CROSS-REFERENCE TO RELATED APPLICATIONS
BACKGROUND OF THE INVENTION
[0002] Appendicitis is a common acute surgical problem affecting human beings of a wide
age range. There are approximately 700,000 cases annually in the United States. A
large proportion of cases occur in the 10 to 30 age group. An accurate diagnosis at
a sufficiently early stage is a significant factor in achieving a successful outcome.
[0003] Many people present to their physician with symptoms suggestive of appendicitis but
caused by other ailments such as viral infections. Differentiating the appendicitis
patients from those affected with other ailments is a daunting clinical task that
physicians face daily. While medical science has an excellent understanding of appendicitis
and its treatment, it is very limited in its ability to accurately recognize or diagnose
the disease.
[0004] Complicating the goal of an accurate and early diagnosis is the considerable overlap
of genuine appendicitis with other clinical conditions. There appears to be no individual
sign, symptom, test, or procedure capable of providing a reliable indication of appendicitis.
Imaging technology is inadequate in identifying and characterizing the appendix, especially
in the early stages of the disease when treatment is likely to be most effective.
Imaging technology is further handicapped by its expense and its dependence upon the
availability of highly trained and experienced people to interpret the studies. This
limitation affects thousands of people every year by inaccurately diagnosing their
problem or by delaying the accurate diagnosis. In cases of appendicitis, delays in
diagnosis are the single most important factor leading to worsening of the condition
and more complications related to the disease. The misdiagnosis of appendicitis can
lead not only to unnecessary surgery but also to delay of proper therapy for the actual
underlying condition.
[0005] A dilemma for surgeons is how to minimize the negative appendectomy rate without
increasing the incidence of perforation among patients referred for suspected appendicitis.
What is desperately needed to more effectively treat this very common ailment is a
simple, reliable diagnostic test that is capable of recognizing the earliest stages
of the disease process.
[0006] The typical pathogenesis in appendicitis begins with obstruction of the lumen, although
an initial inflammation of the organ can precede and even contribute to the obstruction.
The secreted mucus of the appendix fills the closed lumen, causing an increase in
intralumenal pressure and distension. The increased intralumenal pressure can exceed
the level of capillary perfusion pressure, resulting in perturbation of normal lymphatic
and circulatory drainage. Ultimately the appendix can become ischemic. The appendix
mucosa is compromised, which can allow invasion of intralumenal bacteria. In advanced
cases, perforation of the appendix may also occur with spillage of pus into the peritoneal
cavity.
[0007] Currently, the diagnosis of appendicitis is difficult, and the difficulty persists
during various stages in the progression of the condition. The following represents
a hypothetical portrayal of stages and associated clinical presentations. Artisans
of ordinary skill will recognize that a considerable degree of variation will occur
in a given patient population.
[0008] At the earliest stages of inflammation, a patient can present with a variety of non-specific
signs and symptoms. Upon obstruction, presentation can involve periumbilical pain,
mild cramping, and loss of appetite. The progress toward increased lumenal pressure
and distension can be associated with presentation involving the localization of pain
to the right lower quadrant of the abdomen, nausea, vomiting, diarrhea, and low grade
fever. If perforation occurs, a patient can present with severe pain and high fever.
At this very advanced stage, sepsis can be a serious risk with a potentially fatal
outcome.
[0009] Practitioners currently use several tools to aid in appendicitis diagnosis. These
tools include physical examination, laboratory tests, and other procedures. Routine
laboratory tests include complete blood count (CBC) with or without differential and
urinalysis (UA). Other tests include a computed tomography (CT) scan of the abdomen
and abdominal ultrasonography. Procedures can include, for example, laparoscopic examination
and exploratory surgery.
[0010] Flum et al. attempted to determine whether the frequency of misdiagnosis preceding
appendectomy has decreased with increased availability of certain techniques (Flum
DR et al., 2001). These techniques included computed tomography (CT), ultrasonography,
and laparoscopy, which have been suggested for patients presenting with equivocal
signs of appendicitis. Flum et al. concluded as follows: "Contrary to expectation,
the frequency of misdiagnosis leading to unnecessary appendectomy has not changed
with the introduction of computed tomography, ultrasonography, and laparoscopy, nor
has the frequency of perforation decreased. These data suggest that on a population
level, diagnosis of appendicitis has not improved with the availability of advanced
diagnostic testing." The rate of misdiagnosis of appendicitis is about 9 percent in
men and about 23.2 percent in women (Neary, W., 2001).
[0011] Myeloid-related Protein Complex 8/14 (MRP-8/14) is a heterodimeric complex associated
with acute inflammatory conditions (for review see Striz and Trebichavsky, 2004).
The complex belongs to the S100 superfamily of proteins and is also referred to S100A8/9,
L1, macrophage inhibitory related protein and calprotectin. The heterodimer consists
of an 8 kilodalton (MRP-8) and 14 kilodalton (MRP-14) subunit. MRP-8 and MRP-14 are
alternatively named S100A8/calgranulin and S100A9/calgranulin b, respectively. MRP-8/14
is a calcium binding protein originally discovered in macrophages. Neutrophils expressing
high concentrations of MRP-8/14 are found in a variety of inflammatory conditions,
including rheumatoid arthritis, inflammatory bowel disease and allograft rejections
(Frosch et al., 2000; Limburg et al., 2000; Burkhardt et al., 2001).
[0012] MRP-8/14 is not always diagnostic of inflammation. For example, it does not reliably
indicate the presence of inflammatory diverticuli (Gasché, C. 2005). Lymphocytes do
not generally contain MRP-8/14 (Hycult Biotechnology, Monoclonal Antibody to Human
S100A8/A9), and therefore MRP-8/14 is not diagnostic of inflammation characterized
by the presence of lymphocytes but not neutrophils. Also, this protein is not always
associated with opportunistic infections (Froland, M.F., et al., 1994).
[0013] Haptoglobin is an acute phase protein that binds free hemoglobin following hemolysis.
The haptoglobin-hemoglobin complex is removed by the liver. Haptoglobin is a heterotetramer
composed of two alpha and two beta subunits. The alpha and beta units are derived
from a single polypeptide chain precursor that is enzymatically cleaved to produce
the subunits. The molecular weights of the subunits are approximately 9 kd-18 kd and
38 kd for alpha and beta, respectively.
[0014] In addition to being a hemoglobin scavenger, haptoglobin has a wide range of biological
functions (Dobryszycka, 1997). Haptoglobin has been shown to be upregulated and modulate
the immune response in certain infection and inflammatory conditions perhaps by regulating
monocyte function (Arredouani et al., 2005). The alpha subunit has been demonstrated
to be a potentially useful serum marker for ovarian cancer (Ye et al., 2003).
[0015] The ability to accurately diagnose appendicitis would be greatly augmented by the
identification of molecules differentially associated with appendicitis.
SUMMARY OF THE INVENTION
[0016] This invention provides a method for diagnosing appendicitis in a patient suspected
of having appendicitis, comprising testing for the presence of MRP-8/14, at a level
diagnostic of appendicitis, in a sample of whole blood, plasma or serum obtained from
the patient. The method may also comprise identifying at least one classical symptom
of appendicitis in said patient. The method may further comprise identifying the presence
of at least one molecule differentially associated with appendicitis in a fluid or
tissue sample of said patient. It is recognized in the art that the diagnosis of appendicitis
is difficult, and that it is often misdiagnosed. Thus the term "diagnosing appendicitis"
as used herein does not necessarily mean diagnosing appendicitis with more than usual
accuracy. However, in fact, the methods of the present invention have been shown to
provide improvements in correct diagnosis, with almost no false positives and few
false negatives.
D1
Kumar et al., J. Leuckocyte Biol. 70, 59-64 (2001) discloses that "phagocytic activation of neutrophils,
in vivo in acute appendicitis ..., is characterised by loss of cytoplasmic immunoreactivity
for S100A8".
Ikemoto et al., Clin Chem 49, 594-600 (2003) also discloses a an immunoassay test device for MRP-8/14. However, the presence
of MRP-8/14 in blood, plasma or serum is not disclosed, and certainly not suggested
in diagnostic levels for assessment of appendicitis in either document.
Other documents in the art (
Maruniak et al., Fed. Proc. 46, 986 (1987);
EP 0428 080;
US 5,055,389;
Ng and Lai, Yale J. Biol. Med. 75, 41-45 (2002); and
Barcia and Reissenweber, Ann, Diagn. Path. 6, 352-356 (2002)) disclose various methods of diagnosing appendicitis by testing for a molecule differentially
associated with appendicitis, as well as test devices and kits for such methods. However,
none of these documents relate to MRP-8/14.
[0017] The term "differentially associated" with respect to a molecule "differentially associated
with appendicitis" refers: (1) to a molecule present in a patient with appendicitis
and not present in a patient not having appendicitis; (2) to a molecule whose relative
level (amount) is distinguishing between appendicitis and non-appendicitis; (3) to
a molecule present, or present at a level, in conjunction with the presence of other
symptoms of appendicitis, that is diagnostic of appendicitis; and/or (4) to a molecule
present, or present at a level; in conjunction with the lack of symptoms associated
with conditions other than appendicitis in which the presence of the molecule occurs,
that is diagnostic of appendicitis.
[0018] The diagnostic level of such a molecule is also referred to herein as the "threshold
amount" or "threshold level." The molecules differentially associated with appendicitis
are preferably protein antigens.
[0019] Classical symptoms of appendicitis include: pain in the abdomen; pain that starts
near the navel, then moves to the lower right quadrant of the abdomen; anorexia (loss
of appetite); trouble eating accompanied by sleepiness; nausea starting after onset
of pain; vomiting starting after onset of pain; vomiting accompanied by fatigue; constipation;
small stools with mucus; diarrhea; inability to pass gas; low-grade fever; abdominal
swelling; pain in the abdomen worsening; tenesmus (feeling of needing to move the
bowels); high fever; and leukocytosis. Increased plasma viscosity is also associated
with appendicitis. In one embodiment of the invention at least two or more symptoms
of appendicitis are identified.
[0020] In one embodiment of this invention patients are screened to determine whether or
not they have an "interfering condition," i.e., another condition in which the molecule
is present in the type of sample being tested. Patients are tested for the presence
of the molecule if they do not have such an interfering condition; or are tested for
the presence of appendicitis-diagnostic levels of the molecule if they do have such
an interfering condition. Appendix-diagnostic levels when the patient has an interfering
condition are levels higher than those present in patients who have the interfering
condition but do not have appendicitis. Interfering conditions include recent allograft;
septicemia; meningitis; pneumonia; tuberculosis; rheumatoid arthritis; gastrointestinal
cancer; inflammatory bowel disease; skin cancer, periodontitis, preeclampsia, and
AIDS.
[0021] A sample can be a fluid or tissue, and can contain whole blood, plasma, serum, milk,
urine, saliva and/or cells. Fecal samples may also be used. Preferably tissue and
fecal samples are liquefied before testing.
[0022] In one embodiment of this invention at least one additional molecule differentially
associated with appendicitis is tested for. Identification of additional molecules
provides greater accuracy to the method.
[0023] One molecule differentially associated with appendicitis is MRP-8/14. Another is
haptoglobin. Both these molecules can be tested for in diagnosing appendicitis.
[0024] MRP-8/14 levels in the range of about 1 to about 11 µg/ml are present in patients
without appendicitis. Levels higher than this provide increased accuracy in diagnosing
appendicitis. Levels higher than about 10, 11, 13, 15 or 20 µg/ml of MRP-8/14 can
be used to diagnose appendicitis. Haptoglobin levels in the range of about 27-139
mg/dL are found in patients without appendicitis. Levels higher than this, e.g., higher
than 125, 130, 135, 139 and 150 provide increased accuracy in diagnosing appendicitis.
[0025] Other molecules that can be tested for, or that can be tested for in addition to
the foregoing molecules, include unique structural proteins of the gastrointestinal
tract, stress-related inflammatory mediators, immunologic factors, indicators of intestinal
bacterial flora, Plasminogen Activator Inhibitor-1, fatty acid binding proteins, nuclear
factor kappa beta (NFκB), specific appendix antigens (HLA-DR), inflammation associated
antigens; and nucleic acids coding for any of the foregoing, including nucleic acids
coding for MRP-8/14 and haptoglobin. Methods for testing for the presence of nucleic
acids are known to the art.
[0026] Methods involving obtaining a first sample from a patient suspected of having appendicitis
can also comprise identifying at least one molecule differentially associated with
appendicitis by a process including obtaining a second fluid or tissue sample from
a second patient, wherein the second patient has appendicitis; obtaining a third fluid
or tissue sample from a third patient wherein the third patient has a non-appendicitis
condition characterized by at least one symptom of appendicitis; and analyzing the
second and third samples so as to detect a molecule differentially associated with
the appendicitis in the second patient, and then identifying the presence of that
molecule, or presence of an increased level of that molecule, in the first sample,
thereby diagnosing appendicitis. Candidate molecules for this process of identifying
molecules differentially associated with appendicitis include unique structural proteins
of the gastrointestinal tract, stress-related inflammatory mediators, immunologic
factors, indicators of intestinal bacterial flora, Plasminogen Activator Inhibitor-1,
fatty acid binding proteins, nuclear factor kappa beta (NFκB), specific appendix antigens
(HLA-DR), inflammation associated antigens, and nucleic acids coding for any of the
foregoing.
[0027] Also disclosed is a method for identifying a molecule differentially associated with
appendicitis, the method comprising obtaining a sample from each of a plurality of
patients who are undergoing surgery for suspected appendicitis; determining during
surgery whether each said patient has appendicitis or not; and analyzing said samples
for the presence of a molecule differentially associated with appendicitis. The samples
can be blood samples or samples of appendix tissue. This method can also include determining
the amount of each molecule found to be differentially associated with appendicitis
in the sample. In one embodiment of the invention, following identification of the
molecule in tissue, it is also identified in plasma. This requires that samples of
blood be taken from patients suspected of having appendicitis. The amount of the molecule
differentially associated with appendicitis in patients who have appendicitis compared
with those who do not is also determined.
[0028] Methods for diagnosing appendicitis can include using test devices, e.g., cartridge
test devices and dipstick test devices, and/or other means for determining the presence
or absence of a molecule differentially associated with appendicitis, e.g., performing
western blots, northern blots, ELISA tests, protein function tests, PCR and other
assays known to the art. In testing molecules differentially associated with appendicitis
that are present in patients without appendicitis, but upregulated in patients with
appendicitis, assays that test for the relative amount of the molecule present in
patient fluids or tissues as well as the mere presence of the molecule are required.
Cartridge immunoassays can be designed to provide information on relative amounts
of such molecules as described herein. Other assays known to the art including ELISAs
and hospital assay devices such as the Synchron LX system of Beckman Coulter can be
used to provide the amount of such molecules present in the patient, which can then
be compared with amounts present in patients without appendicitis to determine whether
or not the patient has appendicitis.
[0029] The methods for diagnosing appendicitis can include performing an immunological assay
using a monoclonal or polyclonal antibody to the molecule differentially associated
with appendicitis. Such antibodies are known to the art or can be generated by means
known to the art without undue experimentation.
[0030] Also disclosed is an immunoassay test device for detecting the presence of a molecule
differentially associated with appendicitis in a sample. The device comprises a first
monoclonal or polyclonal antibody specific to the molecule, a support for the first
monoclonal or polyclonal antibody, means for contacting the first monoclonal or polyclonal
antibody with the sample, and an indicator capable of detecting binding of the first
monoclonal or polyclonal antibody with the molecule.
[0031] Detecting binding of the antibody with the molecule can include binding the antibody/molecule
complex to a second, labeled antibody which binds to the molecule or to the antibody
of the complex.
[0032] Test devices can be in the form of cartridges, dipsticks, or other conformations
known to the art. The test device can also be part of a kit which can contain instructions
for use, instructions for comparison of test results with results of the same test
done on non-appendicitis patient, additional reagents, such as cells or fluids from
non-appendicitis patients, and other reagents known to the art. These types of assay
devices are known to the art and described, e.g., in
U.S. Patent Publication No. 2003/0224452.
[0033] The methods for diagnosing appendicitis can include comparing the level of the molecule
in the sample with a background level of the same molecule in persons not having appendicitis.
This comparison can be made by any means known to the art. It can include comparing
sample results with results from a second sample taken from a person known not to
have appendicitis, or comparing sample results with a photograph or other representation
of results from a person not having appendicitis. Test devices having means for masking
non-appendicitis levels, e.g. a support having the same color or tone as indicators
showing non-appendicitis levels, or a filter having the same color or tone as a non-appendicitis
level, so that only higher, appendicitis-indicating levels of the molecule are detectable,
e.g., by eye, can also be used. The methods can include use of control fluids having
background levels of the molecule typical of non-appendicitis samples, as well as
colored supports and/or light filters as discussed above.
[0034] When the sample is blood, the method can also include processing the blood by a means
known to the art, such as filtration or centrifugation, for separating plasma or serum
which is to be assayed.
[0035] Antibody supports are known to the art. Antibody supports may be absorbent pads to
which the antibodies are removably or fixedly attached. In the devices disclosed,
any indicator means known to the art to detect antibody binding with the molecule
can be used. The indicator means can include second, labeled, monoclonal or polyclonal
antibodies which bind to the selected protein, which preferably bind to a substantially
different epitope on the selected protein from that to which the first monoclonal
or polyclonal antibodies bind, such that binding of the first monoclonal or polyclonal
antibody will not block binding of the second antibody, or vice versa. The indicator
means can also include a test window through which labeled antibodies can be viewed.
Any label known to the art can be used for labeling the second antibody. The label
may be colloidal gold. The second antibody can be monoclonal or polyclonal. The first
antibody may be a polyclonal or a monoclonal antibody made using a specific polypeptide
sequence of the molecule differentially associated with appendicitis, and the second
antibody may be a different monoclonal or polyclonal antibody which binds to a different
site of the molecule or binds to the first antibody. Antibodies for MRP-8 and MRP-14
are commercially available through Cell Sciences, Canton, MA. Monoclonal antibodies
to haptoglobin useful in the methods of this invention are also known to the art,
e.g., as described in
U.S. Patent No. 5,552,295.
[0036] The sample to be assayed may be a liquid, and the immunoassay test device may be
a lateral flow device comprising inlet means for flowing a liquid sample into contact
with the antibodies. The test device may also include a flow control means for assuring
that the test is properly operating. Such flow control means can include control antigens
bound to a support that capture detection antibodies as a means of confirming proper
flow of sample fluid through the test device. Alternatively, the flow control means
can include capture antibodies in the control region which capture the detection antibodies,
again indicating that proper flow is taking place within the device.
[0037] Methods for detecting the presence of a molecule differentially associated with appendicitis
using the foregoing devices are also disclosed, the methods comprising: providing
an immunoassay test device of this invention; contacting a first antibody with a sample;
and reading an indicator which is capable of detecting binding of the first antibody.
Preferably, binding indicates appendicitis in.the patient being tested. Methods of
using these devices can be performed in the doctor's office, emergency room, or surgery,
rather than requiring sending the patient or the sample to a separate laboratory.
[0038] The devices disclosed are useful for testing the above-mentioned samples. When cells
are tested, e.g., when the molecule differentially associated with appendicitis is
suspected to be in blood or tissue cells rather than serum, the method and/or device
can include a cell-lysing step or means using detergent, puncture or other physical
or chemical process known to the art.
BRIEF DESCRIPTION OF THE FIGURES
[0039] Figure 1: Two-dimensional electrophoresis image of proteins from (A) normal and (B)
diseased appendix tissue. Proteins were separated by isoelectric focusing on the x
axis and by molecular weight on the y axis. The molecular weight in kilodaltons is
shown on the left. The arrow indicates the upregulated protein, AP-93.
[0040] Figure 2: MRP-14 western blot analysis of normal (N) and diseased (A) tissue. The
numbers are sample ID numbers. Molecular weights are shown in kilodaltons.
[0041] Figure 3: MRP-8 western blot analysis of normal (N) and diseased (A) tissue. The
numbers are sample ID numbers. Molecular weights are shown in kilodaltons.
[0042] Figure 4: Relative levels of MRP-8/14 in normal and appendicitis serum as determined
by ELISA. The levels are given as a fraction of the mean for the patients not having
appendicitis, said fraction also being referred to herein as a "fold increase." Dark
bars represent samples from patients having appendicitis. White bars represent samples
from patients not having appendicitis.
[0043] Figure 5: Two-dimensional electrophoresis image of proteins in depleted serum samples
from (A) normal and (B) appendicitis patients. Proteins were separated by isoelectric
focusing on the x-axis and by molecular weight on the y-axis. The molecular weight
in kilodaltons is shown in the right. The tailed arrow indicates the upregulated protein,
AP-77 (haptoglobin alpha subunit). The untailed arrow indicates a control protein
that is equally abundant in diseased vs. normal.
[0044] Figure 6: Two-dimensional electrophoresis image of proteins from (A) normal and (B)
diseased (perforated) appendix tissue. Proteins were separated by isoelectric focusing
on the x axis and by molecular weight on the y axis. The molecular weight in kilodaltons
is shown on the left. The arrow indicates the upregulated protein, AP-91 (haptoglobin
alpha subunit).
[0045] Figure 7: Haptoglobin distribution. Haptoglobin western blot analysis of normal (N)
and diseased (A) tissue. The numbers are sample ID numbers. Molecular weights are
shown in kilodaltons. The alpha and beta subunits are >20 kd and 38 kd, respectively.
DETAILED DESCRIPTION
[0046] The vermiform appendix is recognized as a separate organ from the large and small
intestines. It extends as a finger-like pouch from the base of the ascending colon,
which is also called the cecum. The appendix, like the large intestine, is hollow
and composed of the same three tissue layers. These three layers are a mucosa, muscularis
and a serosa. The appendiceal lumen communicates with the lumen of the cecum via a
round opening (os) through which the appendix adds its secretions to the fecal stream.
These secretions are excess mucus produced from the appendiceal mucosa. In addition
to containing mucus, the appendix also contains numerous bacteria common to the right
colon. Obstruction of the appendiceal lumen is the dominant factor causing acute appendicitis.
While fecaliths are the usual cause of appendiceal obstruction, hypertrophied lymphoid
tissue, inspissated barium from previous x-ray studies, vegetable and fruit seeds,
and intestinal worms like ascarids can also block the appendiceal lumen.
[0047] Following luminal obstruction an escalating cycle of events ensues. The proximal
obstruction of the appendix produces a closed-loop obstruction that blocks the normal
flow of appendiceal mucus into the cecum. The continuing normal secretion of the appendiceal
mucus very rapidly fills the luminal capacity of the appendix (approximately 0.1 cc).
Once the luminal capacity of the appendix is reached additional mucus production from
the obstructed appendix rapidly elevates the intraluminal pressure within the organ.
This elevated intraluminal pressure is exerted outward against the appendiceal wall
and causes the appendix to distend. Distention stimulates nerve endings of the visceral
afferent pain fibers, producing vague, dull, diffuse pain in the midabdomen or lower
epigastrium. Peristalsis is also stimulated by the rather sudden distention, so that
some cramping may be superimposed on the visceral pain early in the course of appendicitis.
[0048] Distention of the appendix continues, not only from continued mucosal secretion,
but also from rapid multiplication of the resident bacteria of the appendix. As pressure
in the organ increases, venous pressure within the appendiceal wall is exceeded. This
rising intraluminal pressure then occludes capillaries and venules, but arteriolar
inflow continues, resulting in engorgement and vascular congestion. Distention of
this magnitude usually causes reflex nausea and vomiting, and the diffuse visceral
pain becomes more severe. The inflammatory process soon involves the serosa of the
appendix and in turn parietal peritoneum in the region, producing the characteristic
shift in pain to the right lower quadrant (RLQ). The disease process is fairly advanced
when pain is localized to the RLQ.
[0049] The mucosa of the gastrointestinal tract; including the appendix, is very susceptible
to impaired blood supply. Thus mucosal integrity is compromised early in the process,
allowing bacterial invasion of the deeper tissue layers. This bacterial invasion leads
to appendiceal destruction and systemic liberation of various bacterial toxins. Fever,
tachycardia, and leukocytosis develop as a consequence of this systemic release of
dead tissue products and bacterial toxins. As progressive appendiceal distention rises,
encroaching on the arteriolar pressure, ellipsoidal infarcts develop in the antimesenteric
border of the appendiceal serosa. As distention, bacterial invasion, compromise of
vascular supply and infarction progress, perforation occurs through one of the infarcted
areas on the antimesenteric border. This perforation then releases the bacteria and
its toxins into the abdominal cavity.
[0050] Appendicitis has been called the "great imitator," as its symptoms are frequently
confused with those of other conditions. This confusion stems from the nonspecific
nature of the pain early in its course and the variability in how appendicitis progresses.
Pain in the right lower quadrant of the abdomen is the hallmark of appendicitis but
this is not typically what the patient first perceives. When the appendiceal lumen
first obstructs, the patient will have few if any symptoms because the appendiceal
lumen has not yet had the chance to fill with mucus. The time required to fill the
appendiceal lumen is proportional to the lumen volume available behind the obstruction.
This is variable and unpredictable, as that volume is dependent upon the individual's
appendix size and precisely where the fecalith or other obstruction is located along
that length. Should the fecalith or other obstruction be close to the tip of the appendix
the available volume is relatively small and the time to symptoms or perforation short.
In contrast, the opposite will be true should the fecalith or other obstruction be
near the base of the appendix and provide for the largest possible appendiceal volume.
[0051] Once the appendix begins to distend, the appendicitis patient will begin to experience
a nonspecific discomfort usually in the mid portion of the abdomen. This discomfort
can be easily confused with common ailments such as indigestion, constipation or a
viral illness. Continued appendiceal distention is also accompanied by some nausea
and frequently vomiting. Rarely is the vomiting severe or unrelenting, which reinforces
the confusion with common ailments.
[0052] Later in the progression of appendicitis, inflammation will have progressed to the
outermost layer of the appendix. This outmost layer is called the serosa and it touches
the inner lining of the abdominal cavity called the peritoneum. This contact irritates
the peritoneum, producing peritonitis that is perceived by the appendicitis patient
as focal pain wherever the appendix is touching the peritoneum. This too can vary
between different individuals. The appendix is most usually located in the right lower
quadrant under an area known as McBurney's point. McBurney's point is a position on
the abdomen that is approximately two-thirds of the distance from the anterior superior
iliac spine in a straight line toward the umbilicus. The appendix can, however, reside
in other locations in which case the peritonitis produced by the appendix will be
in an atypical location. This again is a common factor producing an erroneous diagnosis
and delays surgical treatment in cases of appendicitis.
[0053] Regardless of its location, if appendicitis is allowed to progress the organ will
eventually perforate. This contaminates the abdominal cavity around the perforated
appendix with bacteria producing a severe infection. This infection will usually lead
to a localized intra-abdominal abscess or phlegmon and can produce generalized sepsis.
[0054] To identify molecules differentially associated with appendicitis, a proteomic approach
was used. A protein complex, MRP-8/14, that is present in appendix tissue in patients
with acute appendicitis was identified. The highly correlative nature of this complex
with appendicitis led us to examine MRP-8/14 serum levels in patients with apparent
appendicitis. MRP-8/14 is significantly elevated (p<0.02) in patients with appendicitis
as compared to levels in patients with apparent appendicitis yet having no appendiceal
inflammation. The source of MRP-8/14 in the serum is the inflamed appendix tissue.
This is consistent with the known functions of MRP-8/14.
[0055] The role of MRP-8/14 in inflammation is not fully understood but it does seem to
play a vital role in retaining leukocytes in microcapillaries. Extracellular MRP-8/14
interacts with endothelial cells by binding to heparin sulfate and specifically carboxylated
glycans (Robinson et al., 2002). The intracellular signal pathways and effector mechanisms
induced by binding of MRP-8/14 to endothelial cells are not well defined. However,
interaction of MRP-8/14 with phagocytes increases binding activity of the integrin
receptor CD11b-CD18. This is one of the major adhesion pathways of leukocytes to vascular
endothelium (Ryckman et al., 2003). It is believed that the MRP-8/14 utilizes the
receptor for advanced glycation end products (RAGE). A relative of MRP-8/14, S100A12,
is a specific ligand of RAGE expressed by endothelial cells and their interaction
activates NF-kappa B binding in these cells (Hsieh et al., 2004). The NF-kappa B binding
subsequently induces expression of many proinflammatory molecules, such as various
cytokines or adhesion molecules. Thus, release and extracellular functions of S100
proteins represent a positive feedback mechanism by which phagocytes promote further
recruitment of leukocytes to sites of inflammation. Taken together, these proteins
appear to play a role in a fundamental inflammatory response in certain inflammatory
conditions, and are excellent markers of appendix tissue inflammation.
[0056] Neutrophils are white blood cells that are the first to migrate from the circulation
into sites of inflammation. Within neutrophils, constituting approximately 40% of
total cytosolic proteins is the MRP-8/14 complex. This protein is specifically expressed
only in cells of macrophage lineage, making blood monocytes and acutely activated
macrophages other potential white blood cell sources of these proteins. MRP-8/14 is
not usually expressed in lymphocytes nor resident macrophages or those macrophages
involved in chronic inflammation. These two proteins are also known to be independently
expressed by mucosal epithelium in specific states of acute inflammation.
[0057] In the case of appendicitis, the luminal obstruction and the resultant distention
of the appendiceal wall triggers an inflammatory response. The circulating neutrophils
are then recruited into the area, as are activated macrophages. While the expression
of this protein complex is related to the activity of the macrophages in inflammation,
the exact relationship between MRP-8/14 and cellular activity is not fully known.
What is known is that the intracellular distribution of MRP-8/14 varies with the activation
state of macrophages. Normal macrophages contain the complexes in the cytosol, but
once stimulated, MRP-8/14 translocates from the cytosol to the cell membrane (specifically
with the proteins of the cytoskeleton). This would imply that MRP-8/14 may be related
to cell movement, phagocytosis or inflammatory signal transduction. The roles of cellular
movement and signal transduction may also explain why MRP-8/14 is produced directly
from vascular epithelium such as that lining the blood vessels within the appendix.
[0058] Regardless of its role in certain inflammatory conditions, MRP-8/14's abundance within
cells of acute inflammation makes it an excellent detector and monitor of acute appendicitis.
The first step in the inflammatory process is the recruitment of neutrophils and macrophages
to a specific site. In our study, the specific site is the appendix, where those MRP-8/14-containing
cells will engage the offending stimulus. This engagement will usually result in MRP-8/14
cell death and the liberation of MRP-8/14 from either the cytosol or cell membrane
into the patient's circulation. At the same time, the mucosal linings of the appendix
will start to produce and release MRP-8/14 to facilitate macrophage migration or inflammatory
amplification. This process will then escalate as increasing amounts of MRP-8/14 cells
are recruited by the appendicitis to ultimately release more MRP-8/14 into the circulation.
Other examples of inflammatory states causing increases of extracellular MRP-8/14
and the tendency of these increases of MRP-8/14 to correlate with extent of inflammation
are known. Specifically, chronic bronchitis, cystic fibrosis and rheumatoid arthritis
are all associated with elevated serum levels of MRP-8/14 and the severity of these
diseases is generally proportional to the serum levels of MRP-8/14 detected.
[0059] The physiological role of MRP-8/14 makes it an ideal clinical marker for acute appendicitis.
As patients with appendicitis are generally young and healthy, they generally produce
a vigorous inflammatory response. This vigorous response is believed to liberate MRP-8/14
in the earliest stages of the disease, which then escalates as appendicitis progresses.
Additionally, the diseases known to be associated with elevated levels of MRP-8/14
are not common in this younger age group and usually do not produce symptomology similar
to appendicitis. Finally, as MRP-8/14 is not located in nor associated with lymphocyte
proliferation, this marker is not believed to be elevated in viral infections. This
is an especially powerful advantage for diagnosing appendicitis, as viral infections
are one of the most common imitators of appendicitis.
[0060] Haptoglobin was also identified herein as a useful marker for appendicitis. A differential
proteomic screen of depleted serum identified haptoglobin as a marker for appendicitis.
A second differential screen of appendix tissue confirmed that haptoglobin is upregulated
in the appendix tissue of patients with appendicitis. This finding was confirmed by
western blotting of tissue protein. In particular the alpha subunit isoforms were
present only in diseased tissue. Since haptoglobin is a plasma protein; it is highly
valuable as a biomarker for appendicitis.
EXAMPLES
[0061] Example 1. MRP-8/14.
[0062] The objective of this study was to identify a tissue-specific marker that could contribute
to the decision matrix for diagnosing early acute appendicitis. A proteomic screen
was used to identify a protein in the appendix specifically upregulated in acute appendicitis.
MRP-8/14 was identified as present both in the diseased appendix and in serum of acute
appendicitis patients.
[0063] MATERIALS AND METHODS
[0064] Specimen and Serum Collection. All patients enrolled in this study were treated according
to accepted standards of care as defined by their treating physicians. Prior to being
approached for inclusion in our study, all patients were evaluated by a surgeon and
diagnosed by that surgeon as having appendicitis. The treating surgeon's plans for
these appendicitis patients included an immediate appendectomy. The specifics of all
treatments such as use of antibiotics, operative technique (either open or laparoscopic)
were determined by the individual surgeon.
[0065] Exclusion Criteria: Any patients with pre-existing chronic inflammatory diseases
such as asthma, rheumatoid arthritis, inflammatory bowel disease, psoriasis, or neutropenia.
Pregnancy was also considered an exclusion criterion.
[0066] An investigator counseled all patients about the study and informed consent was obtained.
At the time of informed consent, the subject was assigned an identification number
and non-personal demographic and clinical information was obtained (age, sex, race,
duration of symptoms, white blood count (WBC), results of imaging studies, etc). At
the time of surgery, following induction of general anesthesia, a whole blood sample
(5-10 cc volume) was obtained via peripheral venopuncture. This blood specimen was
then placed on ice. As soon as possible, a small sample (approximately 1 gram) of
inflamed appendix was taken from the pathologic specimen and also placed on ice. The
iced blood specimens were then centrifuged for 20 minutes at 3000 rpm and the separated
serum isolated. This isolated serum and the piece of appendix tissue were then stored
separately, frozen at -80° C.
[0067] Appendicitis Tissue Processing. Appendix tissue from appendectomy patients was harvested
and stored at -80°C until processed. Individual tissue samples were ground into powder
using a sterile mortar and pestle under liquid nitrogen. Protein was extracted from
tissue powder by incubating at 37°C in Extraction Buffer (0.025M Tris-base, 200 mM
Sodium Chloride, 5 mM EDTA, 0.1% Sodium Azide, pH 7.5). Samples were centrifuged for
10 minutes at 14K rpm. Supernatants were stored at -80°C until analysis.
[0068] 2D Gel Analysis of Extracted Tissue Samples. 2D gel analysis was performed on depleted
serum samples and extracted tissue samples. Isoelectric focusing (IEF) and SDS-PAGE
were performed according to the Zoom (Invitrogen) protocol for 2D Gel analysis. Equal
quantities of protein were analyzed on each gel.
[0069] Comparisons between negative serum gel and positive serum gel were made to determine
which proteins were present in positive samples and absent in negative samples. Candidate
gel spots were identified and submitted to MALDI-TOF protein identification analysis
(Linden Biosciences).
[0070] Western Blot Analysis of Extracted Appendix Tissue Samples. Samples. (10 µg) were
subjected to standard Laemmli SDS-PAGE and proteins were transferred to nitrocellulose
membrane for western blot analysis using standard techniques with chemiluminescent
detection. Magic Mark Western Standard (Invitrogen) was used to determine molecular
weight. MRP-8 (Calgranulin A C-19, Santa Cruz, SC-8112) was used in a 1:100 dilution
in 0.5x Uniblock (AspenBio, Inc) for primary antibody. The secondary antibody was
Peroxidase anti-goat IgG (H+L), affinity purified (Vector, PI-9500) in a 1:2000 dilution
in Uniblock. MR-14 (Calgranulin B C-19, Santa Cruz, SC-8114) was used in a 1:100 dilution
in 0.5x Uniblock for primary antibody. The secondary antibody was Peroxidase anti-goat
IgG (H+L), affinity purified (Vector, PI-9500) in a 1:2000 dilution in Uniblock.
[0071] Serum MRP-8/14 Determinations. Serum levels of MRP-8/14 were determined by ELISA
using a commercially available ELISA (Buhlmann S100-Cellion S100 A8/A9) according
to the manufacturer's protocol.
[0073] Identification of Proteins Present in Appendix Tissue from Appendicitis Patients.
A differential proteomic analysis was performed on depleted serum samples with the
goal of identifying proteins elevated in patients with acute appendicitis. The analysis
involved comparing samples from normal patients versus patients with perforated appendices.
Blood samples were obtained immediately prior to surgery. A normal patient in this
study is one that presented with abdominal pain, underwent surgery, and was found
to have a normal appendix. Normal and diseased appendix tissue was collected during
surgery.
[0074] The proteomic approach was to compare a pool of 4 normal samples with a pool of 4
appendicitis samples using two-dimensional electrophoresis. Figure 1 shows the 2D
profile of proteins analyzed. Comparison between the gels was performed and the most
obvious difference is indicated in Figure 1B as AP- 93. Based on the gel in Figure
1, the molecular weight of AP-93 is approximately 14 kilodaltons. The corresponding
gel slice was analyzed by MALDI-TOF and a positive identification was made. The identification
was based upon spectra of two tryptic peptides, NIETIINTFHQYSVK [SEQ ID NO:1] and
LGHPDTLNQGEFKELVR [SEQ ID NO:2]. The peptides correspond to the underlined residues
in the following amino acid sequence of MRP-14 (GenBank Accession Number P06702):
[0075] MTCKMSQLER
NIETIINTFHQYSVKLGHPDTLNQGEFKELVRKDLQNFLK KENKNEKVIEHIMEDLDTNADKQLSFEEFIMLMARLTWASHEKMHEGDEGPGHHH KPGLGEGTP [SEQ ID
NO:3].
[0076] The MALDI-TOF identification of AP-93 as MRP-14 was confirmed by the matching molecular
weights. Based on this data, MRP-14 protein was more highly abundant in the diseased
sample pool than in the normal sample pool.
[0077] Presence of MRP-14 and MRP-8 in Diseased Appendix Tissue. In order to confirm the
presence of MRP-14 in diseased tissue, an anti-MRP-14 antibody was used in western
blotting of tissue extracts from individual normal and diseased appendices. Figure
2 shows the western blot data from 9 normal and 11 appendicitis samples. A 14 kilodalton
band is present in every appendicitis sample. There is no detectable signal in the
normal samples. This data confirms the proteomic screen data and shows that the protein
is an indicator of diseased appendix tissue.
[0078] Since it is known that MRP-8 exists as a dimer with MRP-14, tissue specimens were
also examined for the presence of MRP-8. Figure 3 shows the western blot data using
an anti-MRP-8 antibody on the normal and diseased tissue samples. As expected, MRP-8
is present in all of the diseased appendix samples and not detectible in the normal
appendix tissue. These western blot data show that the MRP-8 and MRP-14 proteins are
markedly more abundant in appendicitis than in normal appendix tissue.
[0079] Elevated Serum Levels of MRP-8/14 Patients with Acute Appendicitis. The high correlation
between appendicitis and the presence of MRP-8/14 in the appendix led us to examine
the MRP-8/14 levels in serum of those patients and other patients subsequently added
to the study. The sera were collected before surgery, banked and analyzed after the
disease status was known. MRP-8/14 levels were measured using a sandwich ELISA specific
for the complex.
[0080] Table 1 lists serum MRP-8/14 levels for 39 patients as determined by an ELISA manufactured
by Hycult (Netherlands) and available commercially through Cell Sciences, Canton,
MA. The amounts are given as fractions compared to an average level for patients in
the study without appendicitis. Note that all patients with appendicitis show a fold-increase
of MRP-8/14 over average normal levels. The procedure was conducted according to instructions
accompanying the ELISA product. The sample numbers do not correspond to the sample
numbers shown in Figures 2 and 3 as the samples were renumbered.
TABLE 1
| Sample Number |
Clinical Diagnosis |
Pathology |
Grading |
Fraction of Normal |
| 1 |
Advanced Appendicitis |
Mild Acute Appendicitis |
2 |
2.80428 |
| 2 |
Normal Appy |
Normal |
1 |
0.960805 |
| 3 |
Advanced Appendicitis |
Transmural Appendicitis |
3 |
5.554904 |
| 4 |
Perforated Appy |
Perforated Appy-Necrosis |
4 |
6.53913 |
| 5 |
Early Appy |
Mild Acute Appendicitis |
2 |
4.562059 |
| 6 |
Early Appy |
Mild-Acute Appendicitis |
1 |
2.881124 |
| 7 |
Horrible perforated |
Perforated Appy-Necrosis |
4 |
7.906886 |
| 8 |
Normal Appy |
Mild Acute Appendicitis |
2 |
3.971489 |
| 9 |
Early Appy |
Transmural Appendicitis |
3 |
3.83328 |
| 10 |
Advanced Appendicitis |
Transmural Appendicitis |
3 |
3.566665 |
| 11 |
Appendicitis |
Mild Acute Appendicitis |
2 |
3.205335 |
| 12 |
Appendicitis |
Transmural Appendicitis |
3 |
5.51224 |
| 13 |
Advanced Appendicitis |
Transmural Appendicitis |
3 |
2.92671 |
| 14 |
Advanced Appendicitis |
Transmural Appendicitis w Necrosis |
4 |
3.866306 |
| 15 |
PERFORATED |
Transmural Appendicitis |
3 |
4.54657 |
| 16 |
Advanced Appendicitis |
Perforated Appy |
4 |
7.01877 |
| 17 |
Advanced Appendicitis |
Transmural Appendicitis |
3 |
4.25998 |
| 18 |
Appendicitis |
Transmural Appendicitis |
3 |
6.90312 |
| 19 |
Normal Appy |
Normal |
1 |
0.838679 |
| 20 |
Normal Appy |
Normal |
1 |
0.590095 |
| 21 |
Early Appy |
Appendicitis with Peri appy changers |
3 |
1.682291 |
| 22 |
Normal Appy |
Normal |
1 |
1.128849 |
| 23 |
Advanced appendicitis |
Transmural Appendicitis |
4 |
2.338583 |
| 24 |
Normal Appy |
Normal |
1 |
2.478035 |
| 25 |
Hot appy |
|
|
2.807046 |
| 26 |
Perforated |
Perforated |
4 |
4.954136 |
| 27 |
Normal |
Normal |
1 |
0.918438 |
| 28 |
Hot |
Hot |
2 |
4.387589 |
| 29 |
Early |
Transmural Appendicitis |
3 |
4.015013 |
| 30 |
Hot |
Transmural Appendicitis |
3 |
2.460902 |
| 31 |
Normal |
Normal |
1 |
0.594943 |
| 32 |
Hot |
Transmural Appendicitis |
3 |
4.211086 |
| 33 |
Perforated |
Transmural Appendicitis |
4 |
3.835219 |
| 34 |
Normal |
Normal |
1 |
1.968859 |
| 35 |
Perforated |
Transmural Appendicitis |
4 |
4.126198 |
| 36 |
Advanced |
Transmural Appendicitis |
3 |
2.423726 |
| 37 |
Hot Appy |
Transmural Appendicitis |
3 |
4.178647 |
| 38 |
Early |
Transmural Appendicitis |
3 |
9.584398 |
| 39 |
Normal |
Transmural Appendicitis |
2 |
2.835339 |
[0081] We have identified a protein complex that is present in the appendix and serum of
appendicitis patients. Based on the western blot data, the presence of MRP-8/14 in
appendix tissue is highly correlative with disease. Furthermore, levels of MRP-8/14
in serum are predictive of appendicitis. We presume that this increase is due to increased
production of these proteins from systemic neutrophil infiltration of the appendix
and possibly direct mucosal production of the proteins by the appendix itself. This
study demonstrates that MRP-8/14 is a useful clinical marker for acute appendicitis.
After our discovery that MRP-8/14 was a molecule differentially associated with appendicitis,
our work was confirmed by the finding of Power, C. et al., 2004 and 2005, who reported
detection of this molecule in feces of patients having acute appendicitis.
[0082] Example 2. Haptoglobin.
[0083] Using a proteomic screen of serum and appendix tissue, we determined that haptoglobin
is upregulated in patients with acute appendicitis. The alpha subunit of haptoglobin
is an especially useful marker in screening for the disease.
[0084] MATERIALS AND METHODS
[0085] Specimen and serum collection, appendicitis tissue processing, 2D gel analysis of
extracted tissue samples, and western blot analysis of extracted appendix tissue samples
were as described above in Example 1, except that for the western blot, affinity-purified
anti-human haptoglobin (Rockland, 600-401-272) was used at a 1:5000 dilution in 0.5x
uniblock for the primary antibody; and the secondary antibody was peroxidase anti-rabbit
IgG (h+I), affinity purified (vector, pi-1000) in a 1:5000 dilution in uniblock.
[0087] Identification of proteins present in appendix tissue from appendicitis patients.
A differential proteomic analysis was performed on depleted serum samples with the
goal of identifying proteins elevated in patients with acute appendicitis. The analysis
involved comparing samples from normal patients versus patients with perforated appendices.
Blood samples were obtained immediately prior to surgery. A normal patient in this
study is one that presented with abdominal pain, underwent surgery, and was found
to have a normal appendix. Normal and diseased appendix tissue was collected during
surgery.
[0088] The proteomic approach was to compare a pool of 4 normal samples with a pool of 4
appendicitis samples using two-dimensional electrophoresis. Figure 5 shows the 2D
profile of proteins analyzed from serum depleted of IgG and albumin. Comparison between
the gels was performed and the most obvious difference is indicated in Figure 5B as
AP- 77. The protein in gel spot AP-77 was digested with trypsin and analyzed by MALDI-TOF.
The resulting two peptides have the following sequences: TEGDGVYTLNNEKQWINK [SEQ ID
NO:4] and AVGDKLPECEADDGCPKPPEIAHGYVEHSVR [SEQ ID NO:5]. The sequences were aligned
with the alpha subunit of haptoglobin. The sequence of haptoglobin precursor (GenBank
Accession Number NP005134) is shown below with the tryptic fragments underlined.
[0089] MSALGAVIALLLWGQLFAVDSGNDVTDIADDGCPKPPEIAHGYVEHSVR YQCKNYYKLR
TEGDGVYTLNDKKQWINKAVGDKLPECEADDGCPKPPEIAHGYVE HSVRYQCKNYYKLRTEGDGVYTLNNEKQWINKAVGDKLPECEAVCGKPKNPANPV QRILGGHLDAKGSFPWQAKMVSHHNLTTGATLINEQWLLTTAKNLFLNHSENATAK
DIAPTLTLYVGKKQLVEIEKVVLHPNYSQVDIGLIKLKQKVSVNERVMPICLPSKDYA EVGRVGYVSGWGRNANFKFTDHLKYVMLPVADQDQCIRHYEGSTVPEKKTPKSPV
GVQPILNEHTFCAGMSKYQEDTCYGDAGSAFAVHDLEEDTWYATGILSFDKSCAV AEYGVYVKVTSIQDWVQKTIAEN [SEQ
ID NO:6].
[0090] Figure 6 shows the two-dimensional electrophoresis profile comparison between diseased
and normal appendix tissue proteins. Two spots, AP-91 and AP-93, were analyzed by
MALDI-TOF and positive identifications were determined. AP-91 protein was determined
to be identical to AP-77, haptoglobin-alpha.
[0091] Elevated haptoglobin in diseased appendix tissue. In order to confirm the presence
of haptoglobin in diseased tissue, an anti-haptoglobin antibody was used in western
blotting of tissue extracts from individual normal and diseased appendices. Figure
7 shows the western blot data from 6 normal and 6 appendicitis samples. Nearly every
sample contained some level of the 38 kd beta subunit, however, there appeared to
be an elevated level in cases of appendicitis. A >20 kilodalton band is present in
every appendicitis sample and absent from all of the normal tissue samples. This data
confirms the proteomic screen data and shows that the protein is an indicator of diseased
appendix tissue. The alpha subunit has higher specificity than the beta subunit.
[0092] Example 3. Method of identifying molecules using fluid samples.
[0093] In variations of this example, fluid samples can include whole blood, serum, or plasma.
The samples are whole blood collected from human patients immediately prior to an
appendectomy. The specimens are placed on ice and transported to the lab. The blood
is then processed by centrifugation at 3000 rpm for 15 minutes. Plasma is then separated
by pouring into another container
[0094] Upon performing an appendectomy, a patient is classified as having appendicitis (AP)
or non-appendicitis (NAP). The classification is based on clinical evaluation, pathology,
or both as known in the art. For cases of appendicitis, the clinical condition is
also characterized as either perforated or non-perforated.
[0095] The samples from AP patients are optionally pooled and divided into aliquots. Optionally,
a pooled aliquot is treated so as to remove selected components such as antibodies
and serum albumin. Similarly, the samples from NAP patients are optionally pooled
and divided into aliquots with optional treatment to remove the same selected components.
Preferably the AP samples and NAP samples are processed in a similar manner.
[0096] Next, the pooled aliquots of AP and NAP samples are each subjected to two-dimensional
gel electrophoresis as known in the art. The results of each sample type are compared
with respect to the presence, absence, and relative expression levels of proteins.
Preferably, one detects a signal corresponding to a protein derived from an AP sample
that is either absent or expressed at relatively lower levels in a NAP sample. Further
characterization is performed for such an AP protein.
[0097] The further characterization can include partial amino acid sequencing, mass spectrometry,
and other analytical techniques as known in the art. A full length clone of the gene
corresponding to the partial amino acid sequence can be isolated and expressed as
a recombinant protein. The recombinant protein can be used as an antigen for detection.
Alternatively, a partial or complete recombinant protein can be used to induce or
otherwise generate a specific antibody reagent, polyclonal or monoclonal. The antibody
reagent is used in the detection of antigen in a patient so as to aid in appendicitis
diagnosis. A combination of antigenic molecules can be employed in appendicitis diagnosis.
[0098] Example 4. Method of identifying molecules using tissue samples.
[0099] Tissue samples are collected from appendicitis (AP) and non-appendicitis (NAP) patients.
Preferably the tissue is the appendix. The AP or NAP tissues samples are optionally
pooled so as to generate an AP tissue pool or an NAP tissue pool. The AP and NAP tissue
samples are each used as a source for isolation of total RNA and/or mRNA. Upon isolation,
the AP-RNA and NAP-RNA are maintained separately and used for preparation of cDNA.
[0100] A subtraction library is created using techniques available in the art. A cDNA library
is optionally amplified. The cDNA library is treated so as to remove undesirable constituents
such as highly redundant species and species expressed both in diseased and normal
samples. Examples of the techniques include those described by Bonaldo et al. (1996)
and Deichmann M et al. (2001).
[0101] Upon generation of the subtraction library, one analyzes, isolates, and sequences
selected clones corresponding to sequences differentially expressed in the disease
condition. Using molecular biology techniques, one selects candidates for recombinant
expression of a partial or complete protein. Such a protein is then used as an antigen
for detection. Alternatively, a partial or complete recombinant protein can be used
to induce or otherwise generate a specific antibody reagent, polyclonal or monoclonal.
The antibody reagent is used in the detection of antigen in a patient so as to aid
in appendicitis diagnosis. It is envisioned that a combination of antigenic molecules
can be employed in appendicitis diagnosis
[0102] Example 5. Method of appendicitis diagnosis by evaluation of plasma sample viscosity.
[0103] Whole blood is drawn from a suspected appendicitis patient immediately prior to appendectomy.
The specimens are placed on ice and transported to the clinical lab. The blood is
processed by centrifugation at 3000 rpm for 15 minutes followed by separation of plasma
from the sample by pouring into another container.
[0104] During the step of pouring, the samples are evaluated with respect to viscosity.
Increased viscosity is indicative of appendicitis. Approximately 80% of samples corresponding
to appendicitis cases demonstrate increased viscosity, whereas approximately none
to less than 5% of samples corresponding to non-appendicitis cases demonstrate increased
viscosity. It is noted that the degree of increased viscosity can correlate with the
severity of appendicitis.
[0105] Viscosity measurements can be conducted by visual observation or by using techniques
known in the art. For example, a Coulter Harkness capillary viscometer can be used
(Harkness J., 1963) or other techniques (Haidekker MA, et al., 2002).
[0106] The presence of increased viscosity in plasma may be used in combination with other
diagnostic techniques, for example with one or more of the following: physical examination,
complete blood count (CBC) with or without differential, urinalysis (UA), computed
tomography (CT), abdominal ultrasonography, and laparoscopy.
[0107] Where the terms "comprise", "comprises", "comprised", or "comprising" are used herein,
they are to be interpreted as specifying the presence of the stated features, integers,
steps, or components referred to, but not to preclude the presence or addition of
one or more other feature, integer, step, component, or group thereof.
REFERENCES
[0141] Fagerhol MK, Andersson KB, Naess-Andresen CF, Brandtzaeg P, Dale I. Calprotectin (The
L1 Leukocyte Protein) In: VL Smith & JR Dedman (Eds): Stimulus Response Coupling.
The Role of Intracellular Calcium-Binding Proteins, CRC Press, Boca Raton, Fla., USA,
1990, pp. 187-210.
[0156] Hanai H, Takeuchi K, Iida T, Arai H, Kanaoka K, Iwasaki T, Nakamura A, Hosoda Y, Shirai
N; Hirasawa K, Takahira K, Kataoka H, Sano M, Osawa M, Sugimoto S. Clinical significance
of faecal calprotectin levels in patients with ulcerative colitis. Nippon Shokakibyo
Gakkai Zasshi 2003; 100:21.
[0161] Hycult Biotechnology b.v., ELISA Test Kit for Human Calprotectin information sheet,
Catalog No. HK325.
[0162] Hycult Biotechnology b.v., Monoclonal Antibody to Human S100A8/A9 (MRP-8/MRP-14),
calprotectin Clone 27E10 information sheet, Catalog No. HM2156.
[0206] Tibble JA, Bjarnason I. Department of Medicine, Guy's, King's, St Thomas's Medical
School, Bessemer Road, London SE5 9PJ, UK.Non-invasive investigation of flammatory
bowel disease.
[0207] Tibble JA, Bjarnason I. Department of Medicine, Guy's, King's, St. Thomas's Medical
School, London, UK. Fecalcalprotectin as an index of intestinal inflammation.
[0219] Ye B, Cramer DW, Skates SJ, Gygi SP, Pratomo V, Fu L, Horick NK, Licklider LJ, Schorge
JO, Berkowitz RS, Mok SC. 2003 Haptoglobin-alpha subunit as potential serum biomarker
in ovarian cancer: identification and characterization using proteomic profiling and
mass spectrometry. Clin Cancer Res 9(8):2904-11.
SEQUENCE LISTING
[0221]
<110> AspenBio Pharma, Inc.
<120> Methods and Devices for Diagnosis of Appendicitis
<130> EPP96908
<140> WO 2006/012588 (EP 05775574.6)
<141> 2005-07-25
<150> US 60/590,631
<151> 2004-07-23
<160> 6
<170> PatentIn version 3.2
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1. A method for use in the diagnosis of appendicitis in a patient suspected of having
appendicitis, comprising testing for the presence of MRP-8/14, at a level diagnostic
of appendicitis, in a sample of whole blood, plasma or serum obtained from the patient.
2. A method according to claim 1, wherein said patient presents with at least one classical
symptom of appendicitis selected from the group consisting of: pain in the abdomen;
pain that starts near the navel, then moves to the lower right quadrant of the abdomen;
anorexia (loss of appetite); trouble eating accompanied by sleepiness; nausea starting
after onset of pain; vomiting starting after onset of pain; vomiting accompanied by
fatigue; constipation; small stools with mucus; diarrhoea; inability to pass gas;
low-grade fever; abdominal swelling; pain in abdomen worsening; tenesmus; high fever;
leukocytosis; and increased plasma viscosity.
3. A method according to claim 2, wherein said patient presents with two or more of said
classical symptoms of appendicitis.
4. A method according to any of claims 1 to 3, performed in an immunological assay device.
5. A method according to any preceding claim, wherein the patient is not known to have
an interfering condition associated with the presence of MRP-8/14 in a sample of the
type in which MRP-8/14 is tested for,
wherein said interfering condition is selected from the group consisting of recent
allograft; septicaemia; meningitis; pneumonia; tuberculosis; rheumatoid arthritis;
gastrointestinal cancer; inflammatory bowel disease; skin cancer, periodontitis, pre-eclampsia,
and AIDS.
6. A method according to any preceding claim, wherein a level of MRP-8/14 higher than
about 10 µg/ml of MRP-8/14 is diagnostic of appendicitis is tested for.
7. A method according to any preceding claim, wherein a level of MRP-8/14 higher than
about 11 µg/ml of MRP-8/14 is tested for.
8. A method according to any preceding claim, wherein a level of MRP-8/14 higher than
about 15 µg/ml of MRP-8/14 is tested for.
9. A method according to any preceding claim, wherein a level of MRP-8/14 higher than
about 20 µg/ml of MRP-8/14 is diagnostic of appendicitis.
10. A method according to any preceding claim, wherein at least one additional molecule
differentially associated with appendicitis is tested for, wherein said at least one
additional molecule is selected from the group consisting of: Plasminogen Activator
Inhibitor-1, fatty acid binding proteins, nuclear factor kappa beta (NFκB), nucleic
acids coding for any of the foregoing, and haptoglobin.
11. A method according to claim 10, wherein a level of haptoglobin higher than 139 mg/dL
is tested for.
12. A method according to claim 10, wherein a level of haptoglobin higher than 150 mg/dL
is tested for.
13. A method according to any preceding claim, wherein said MRP-8/14 and said at least
one additional molecule are tested for by testing for the presence of a nucleic acid
sequence coding for said MRP-8/14 or said at least one additional molecule in said
sample.
14. A method according to claim 1, wherein said MRP-8/14 is tested for using antibody
27e10.
1. Verfahren zur Anwendung bei der Diagnose von Appendizitis bei einem Patienten mit
Verdacht auf Appendizitis, wobei das Verfahren aufweist: Test auf Anwesenheit von
MRP-8/14 in einer für Appendizitis symptomatischen Konzentration in einer von dem
Patienten entnommenen Vollblut-, Plasma- oder Serumprobe.
2. Verfahren nach Anspruch 1, wobei sich der Patient mit mindestens einem klassischen
Symptom von Appendizitis präsentiert, das aus der Gruppe ausgewählt ist, die aus den
folgenden Symptomen besteht: Bauchschmerz; Schmerz, der in Nabelnähe beginnt, sich
dann zum unteren rechten Viertel des Bauchs bewegt; Anorexie (Appetitlosigkeit); Eßstörung,
begleitet von Schläfrigkeit; nach Schmerzanfall beginnende Übelkeit, nach Schmerzanfall
beginnendes Erbrechen, von Müdigkeit begleitetes Erbrechen; Verstopfung; kleiner Stuhl
mit Schleim; Durchfall; Unfähigkeit, einen fahren zu lassen; schwaches Fieber; Unterleibsschwellung;
sich verschlimmernder Bauchschmerz; Tenesmus; hohes Fieber, Leukozytose und erhöhte
Plasmaviskosität.
3. Verfahren nach Anspruch 2, wobei sich der Patient mit zwei oder mehreren der klassischen
Appendizitis-Symptome präsentiert.
4. Verfahren nach einem der Ansprüche 1 bis 3, das in einer immunologischen Biotest-
bzw. Assay-Vorrichtung durchgeführt wird.
5. Verfahren nach einem der vorstehenden Ansprüche, wobei von dem Patienten nicht bekannt
ist, daß er an einem störenden Zustand leidet, der mit der Anwesenheit von MRP-8/14
in einer Probe von dem Typ assoziiert ist, in dem auf MRP-8/14 getestet wird,
wobei der störende Zustand aus der Gruppe ausgewählt ist, die aus den folgenden besteht:
kürzliches allogenes Transplantat; Septikämie, Meningitis, Pneumonie; Tuberculose;
Rheumatoidarthritis; Gastrointestinalkrebs; entzündliche Darmerkrankung; Hautkrebs;
Periodontitis; Präeklampsie und AIDS.
6. Verfahren nach einem der vorstehenden Ansprüche, wobei auf eine höhere MRP-8/14-Konzentration
als etwa 10 µg/ml MRP-8/14 getestet wird, die symptomatisch für Appendizitis ist.
7. Verfahren nach einem der vorstehenden Ansprüche, wobei auf eine höhere MRP-8/14-Konzentration
als etwa 11 µg/ml MRP-8/14 getestet wird.
8. Verfahren nach einem der vorstehenden Ansprüche, wobei auf eine höhere MRP-8/14-Konzentration
als etwa 15 µg/ml MRP-8/14 getestet wird.
9. Verfahren nach einem der vorstehenden Ansprüche, wobei eine höhere MRP-8/14-Konzentration
als etwa 20 µg/ml MRP-8/14 symptomatisch für Appendizitis ist.
10. Verfahren nach einem der vorstehenden Ansprüche, wobei auf mindestens ein weiteres
Molekül getestet wird, das selektiv mit Appendizitis assoziiert ist, wobei das mindestens
eine weitere Molekül aus der Gruppe ausgewählt ist, die aus den folgenden besteht:
Plasminogenaktivator-Inhibitor-1, fettsäurebindende Proteine, Nuklearfaktorkappa-Beta
(NFκB) und Nucleinsäuren, die für eines der vorstehenden Moleküle codieren, und Haptoglobin.
11. Verfahren nach Anspruch 10, wobei auf eine höhere Haptoglobin-Konzentration als 139
mg/dl getestet wird.
12. Verfahren nach Anspruch 10, wobei auf eine höhere Haptoglobin-Konzentration als 150
mg/dl getestet wird.
13. Verfahren nach einem der vorstehenden Ansprüche, wobei auf das MRP-8/14 und das mindestens
eine weitere Molekül getestet wird, indem auf die Anwesenheit einer Nucleinsäuresequenz
in der Probe getestet wird, die für das MRP-8/14 oder das mindestens eine weitere
Molekül codiert.
14. Verfahren nach Anspruch 1, wobei mit dem Antikörper 27e10 auf das MRP-8/14 getestet
wird.
1. Méthode pour une utilisation dans le diagnostic de l'appendicite chez un patient suspecté
d'avoir l'appendicite, comprenant un test sur la présence de MRP-8/14, à un niveau
qui est un diagnostic de l'appendicite, dans un échantillon de sang entier, de plasma
ou de sérum obtenu à partir du patient.
2. Méthode selon la revendication 1, dans laquelle ledit patient présente au moins un
symptôme classique de l'appendicite choisi dans le groupe constitué: d'une douleur
dans l'abdomen; d'une douleur qui débute près du nombril, puis se déplace vers le
quadrant droit inférieur de l'abdomen; d'une anorexie (perte d'appétit); d'un trouble
de l'alimentation accompagné d'une insomnie; de nausées débutant après le déclenchement
d'une douleur; de vomissements débutant après le déclenchement d'une douleur; de vomissements
accompagnés d'une fatigue; d'une constipation; de petites selles avec du mucus; d'une
diarrhée; d'une incapacité à faire passer les gaz; d'une faible fièvre; d'un gonflement
abdominal; d'une douleur dans l'abdomen qui empire; d'un ténesme; d'une forte fièvre;
d'une leucocytose; et d'une augmentation de la viscosité du plasma.
3. Méthode selon la revendication 2, dans laquelle ledit patient présente deux ou plus
desdits symptômes classiques de l'appendicite.
4. Méthode selon l'une quelconque des revendications 1 à 3, effectuée dans un dispositif
de dosage immunologique.
5. Méthode selon l'une quelconque des revendications précédentes, dans laquelle le patient
n'est pas connu pour avoir un état interférant associé à la présence de MRP-8/14 dans
un échantillon du type dans lequel MRP-8/14 est testé, dans laquelle ledit état interférant
est choisi dans le groupe constitué d'une allogreffe récente; d'une septicémie; d'une
méningite; d'une pneumonie; d'une tuberculose; d'une polyarthrite rhumatoïde; d'un
cancer gastro-intestinal; d'une maladie intestinale inflammatoire; d'un cancer de
la peau, d'une parodontite, d'une pré-éclampsie et d'un SIDA.
6. Méthode selon l'une quelconque des revendications précédentes, dans laquelle un niveau
de MRP-8/14 supérieur à environ 10 µg/ml de MRP-8/14 qui est testé est un diagnostic
de l'appendicite.
7. Méthode selon l'une quelconque des revendications précédentes, dans laquelle un niveau
de MRP-8/14 supérieur à environ 11 µg/ml de MRP-8/14 est testé.
8. Méthode selon l'une quelconque des revendications précédentes, dans laquelle un niveau
de MRP-8/14 supérieur à environ 15 µg/ml de MRP-8/14 est testé.
9. Méthode selon l'une quelconque des revendications précédentes, dans laquelle un niveau
de MRP-8/14 supérieur à environ 20 µg/ml de MRP-8/14 est un diagnostic de l'appendicite.
10. Méthode selon l'une quelconque des revendications précédentes, dans laquelle au moins
une molécule supplémentaire associée différemment avec l'appendicite est testée, dans
laquelle ladite au moins une molécule supplémentaire est choisie dans le groupe constitué:
de l'inhibiteur-1 des activateurs du plasminogène, de protéines de liaison d'acide
gras, d'un facteur nucléaire kappa bêta (NFκB), d'acides nucléiques codant pour n'importe
lequel de ce qui précède, et l'haptoglobine.
11. Méthode selon la revendication 10, dans laquelle un niveau d'haptoglobine supérieur
à 139 mg/dl est testé.
12. Méthode selon la revendication 10, dans laquelle un niveau d'haptoglobine supérieur
à 150 mg/dl est testé.
13. Méthode selon l'une quelconque des revendications précédentes, dans laquelle ledit
MRP-8/14 et ladite au moins une molécule supplémentaire sont testés en testant la
présence d'une séquence d'acide nucléique codant pour ledit MRP-8/14 ou ladite au
moins une molécule supplémentaire dans ledit échantillon.
14. Méthode selon la revendication 1, dans laquelle ledit MRP-8/14 est testé en utilisant
l'anticorps 27e10.