Diagnostic role and clinical correlates of anti-Saccharomyces cerevisiae antibodies (ASCA) and anti-neutrophil cytoplasmic antibodies (p-ANCA) in Italian patients with inflammatory bowel diseases

Inflammation, Autoinflammation and Autoimmunity in Inflammatory Bowel Diseases

In this review, the role of innate and adaptive immunity in the pathogenesis of inflammatory bowel diseases (IBD) is reported. In IBD, an altered innate immunity is often found, with increased Th17 and decreased Treg cells infiltrating the intestinal mucosa. An associated increase in inflammatory cytokines, such as IL-1 and TNF-α, and a decrease in anti-inflammatory cytokines, such as IL-10, concur in favoring the persistent inflammation of the gut mucosa. Autoinflammation is highlighted with insights in the role of inflammasomes, which activation by exogenous or endogenous triggers might be favored by mutations of NOD and NLRP proteins. Autoimmunity mechanisms also take place in IBD pathogenesis and in this context of a persistent immune stimulation by bacterial antigens and antigens derived from intestinal cells degradation, the adaptive immune response takes place and results in antibodies and autoantibodies production, a frequent finding in these diseases. Inflammation, autoinflammation and autoimmunity concur in altering the mucus layer and enhancing intestinal permeability, which sustains the vicious cycle of further mucosal inflammation.

Butyrate Protects Myenteric Neurons Loss in Mice Following Experimental Ulcerative Colitis

The enteric nervous system is affected by inflammatory bowel diseases (IBD). Gut microbiota ferments dietary fibers and produces short-chain fatty acids, such as Butyrate, which bind to G protein-coupled receptors, such as GPR41, and contribute to maintaining intestinal health. This work aimed to study the GPR41 in myenteric neurons and analyze the effect of Butyrate in mice submitted to experimental ulcerative colitis. The 2, 4, 6 trinitrobenzene sulfonic acid (TNBS) was injected intrarectally in C57BL/6 mice (Colitis). Sham group received ethanol (vehicle). One group was treated with 100 mg/kg of Sodium Butyrate (Butyrate), and the other groups received saline. Animals were euthanized 7 days after colitis induction. Analyzes demonstrated colocalization of GPR41 with neurons immunoreactive (-ir) to nNOS and ChAT-ir and absence of colocalization of the GPR41 with GFAP-ir glia. Quantitative results demonstrated losses of nNOS-ir, ChAT-ir, and GPR41-ir neurons in the Colitis group and Butyrate treatment attenuated neuronal loss. The number of GFAP-ir glia increased in the Colitis group, whereas Butyrate reduced the number of these cells. In addition, morphological alterations observed in the Colitis group were attenuated in the Butyrate group. The presence of GPR41 in myenteric neurons was identified, and the treatment with Butyrate attenuated the damage caused by experimental ulcerative colitis.

Serum ANCA as Disease Biomarkers: Clinical Implications Beyond Vasculitis

Usually associated with autoimmune diseases, anti-neutrophil cytoplasmic antibodies are also detected in other conditions, such as infections, malignancies, and after intake of certain drugs. Even if the mechanisms of production and their pathogenic role have not been fully elucidated yet, ANCA are widely recognized as a clinically alarming finding due to their association with various disorders. While ANCA target several autoantigens, proteinase-3, and myeloperoxidase are the ones proved to be most frequently related to chronic inflammation and tissue damage in murine models. Albeit these autoantibodies could be present as an isolated observation without any implications, ANCA are frequently used in clinical practice to guide the diagnosis in a suspect of small vessel vasculitis. Conditions that should prompt the clinician to test ANCA status range from various forms of lung disease to renal or peripheral nervous system impairment. ANCA positivity in the presence of an autoimmune disease, especially rheumatoid arthritis, or connective tissue diseases, is frequently correlated with more clinical complications and treatment inefficacy, even in the absence of signs of vasculitis. For this reason, it has been postulated that ANCA could represent the final expression of an immune dysregulation rather than a pathogenic event responsible for organs damage. Recently, it has also been proposed that ANCA specificity (PR3 or MPO) could possibly define ANCA-associated vasculitides better than clinical phenotype. This review aims at summarizing the latest advancements in the field of ANCA study and clinical interpretation.

Adverse Reaction to Zirconia in a Modern Total Hip Arthroplasty with Ceramic Head

Hypersensitivity reactions to zirconia (ZrO2) or similar ceramics is highly unusual. Owing to the stable oxide formed between the base metal and oxygen, ceramics are considered relatively biologically inert. We report the case of an otherwise healthy 50-year-old woman with a 5-year history of progressively worsening right hip pain who underwent a ceramic-on-polyethylene total hip replacement and subsequently developed hypersensitivity reaction. After metal allergy testing showed her to be highly reactive to zirconium, the femoral head was revised to a custom titanium implant and her symptoms resolved.

Inflammatory Bowel Disease in Children: Experience and Constraints in a Resource-limited Setting

Introduction: Inflammatory bowel disease (IBD), though well described in the Caucasian population, is rarely encountered in the black African children. The aim of this study was to increase the awareness of this emerging condition in African children and highlight the constraints of management in a resource-limited setting like Nigeria.

Methods: This study included an audit of children with IBD who were seen between January 2015 and February 2020 at the Lagos University Teaching Hospital (LUTH). The clinical records of children aged one to 16 years who presented with recurrent abdominal pain, weight loss, and gastrointestinal (GI) bleeding with clinical suspicion of IBD were reviewed. Clinical features, endoscopic findings, histopathologic findings, and treatment were documented.

Results: Eight children with IBD were seen during the study period. The median age was 12.0 years (range: five to 15 years). The most common reported concerns in the children were chronic abdominal pain [seen in four patients (50%)] and bloody diarrhea [seen in three patients (42.30%)]. Weight loss and arthritis were seen in three (37.5%) and one (12.5%) children, respectively. Endoscopy confirmed two cases of Crohn’s disease (CD), three cases of ulcerative colitis (UC), and three cases of indeterminate colitis (IC). The children with CD were treated with steroids and exclusive enteral nutrition, with one patient receiving methotrexate, while the UC and IC patients received 5-aminosalicylate therapy.

Conclusion: Although IBD is uncommon in Nigeria, a high index of suspicion is vital to enable early diagnosis and appropriate treatment. Management in the African setting is severely constrained by limited access to endoscopy facilities and nonavailability of other effective treatment options such as biologic agents.

The significance of ANCA positivity in patients with inflammatory bowel disease

Traditionally anti-neutrophil cytoplasmic antibodies (ANCA) are used to subtype patients with inflammatory bowel disease (IBD) and to predict primary sclerosing cholangitis (PSC). The clinical utility of this testing in the Australian context is not known. Our retrospective, cross-sectional study looked at the results of ANCA testing performed during routine clinical review and aimed to retrospectively review (1) the distribution of different ANCA subtypes for IBD patients, (2) the temporal change of ANCA status, and (3) the predictive value of ANCA for PSC. Sixty-four IBD patients attending our hospital gastroenterology clinic between 2012 and 2016 had at least one ANCA test requested. Surprisingly, >80% of the IBD patients in our cohort who underwent ANCA testing had a positive ANCA result and a significant proportion had positive PR3 antibodies. However, no specific ANCA pattern predicted a specific IBD subtype or clinical course. Pairing ANCA and anti-Saccharomyces cerevisiae (ASCA) did not add value in subtyping IBD for these patients. Our study suggests that there is little value in ordering an ANCA for patients with IBD.

Retrospective evaluation of the clinical utility of serological biomarkers in Chinese patients with inflammatory bowel disease: 2-year clinical experience

BACKGROUND

Antibodies to saccharomyces cerevisiae (ASCA), antibodies to perinuclear anti-neutrophil cytoplasmic (pANCA), pancreatic autoantibodies (PAB) and antibodies against intestinal goblet cells (GAB) are important in diagnosing Crohn's disease (CD) and ulcerative colitis (UC). However, little is known about their diagnostic value in real clinical practice in China. This retrospective study aimed to present our 2-year clinical experience with those biomarkers in diagnosis of CD and UC.

METHODS

A total of 140 patients with UC, 128 patients with CD, and 224 patients with intestinal associated diseases as disease controls were included. Serum ASCA were determined by ELISA. Serum pANCA, GAB, and PAB were tested by indirect immunofluorescent assay. Retrospective review of laboratory results and clinical information was performed.

RESULTS

ASCA and ASCA+/pANCA- showed poor abilities in differentiating CD from UC, CD from intestinal Behçet's disease (BD), or CD from intestinal tuberculosis (ITB). In contrast, PAB exhibited good capacities in differentiating CD from UC, CD from intestinal BD, and CD from ITB. IgG pANCA demonstrated a high sensitivity and specificity in differentiating UC from CD. pANCA+/ASCA- or pANCA+/PAB- displayed a high sensitivity and specificity in differentiating UC from CD. GAB showed poor potential in differentiating UC from CD. PAB were positively correlated with early disease onset, ileocolonic disease, and perianal disease in CD patients.

CONCLUSIONS

Our data suggest that pANCA and PAB are helpful in diagnosis of UC and CD, respectively, while ASCA and GAB were not. Our findings indicate a clear need for additional biomarkers for diagnosis of CD in China.

Coexistence of ulcerative colitis and Sjögren's syndrome in a patient with Takayasu's arteritis and Hashimoto's thyroiditis

A 31-year-old woman with a 15-year history of Takayasu's arteritis (TA) and a 13-year history of Hashimoto's thyroiditis presented with hematochezia. She received a diagnosis of Sjögren's syndrome at 1 month before her visit to Kyungpook National University Medical Center. Her colonoscopic findings were compatible with a diagnosis of ulcerative colitis (UC). She was treated with oral mesalazine, and her hematochezia symptoms subsequently disappeared. The coexistence of UC and TA has been reported; however, reports on the coexistence of UC and Sjögren's syndrome, or of UC and Hashimoto's thyroiditis are rare. Although the precise etiologies of these diseases are unknown, their presence together suggests that they may have a common pathophysiologic background. Furthermore, in patients with autoimmune or vascular diseases, including TA, systemic manifestations should be assessed with consideration of inflammatory bowel diseases including UC in the presence of gastrointestinal symptoms such as diarrhea and hematochezia.

Approach to the Management of Autoimmunity in Primary Immunodeficiency

Primary immunodeficiency diseases (PIDs) consist of a genetically heterogeneous group of immune disorders that affect distinct elements of the immune system. PID patients are more prone to infections and non-infectious complications, particularly autoimmunity. The concomitance of immunodeficiency and autoimmunity appears to be paradoxical and leads to difficulty in the management of autoimmune complications in PID patients. Therefore, management of autoimmunity in patients with PID requires special considerations because dysregulations and dysfunctions of the immune system along with persistent inflammation impair the process of diagnosis and treatment.

Autoimmunity and the microbiome: T-cell receptor mimicry of "self" and microbial antigens mediates self tolerance in holobionts: The concepts of "holoimmunity" (TcR-mediated tolerance for the holobiont) and "holoautoimmunity" (loss of tolerance for the holobiont) are introduced

I propose a T-cell receptor (TcR)-based mechanism by which immunity mediates both "genetic self" and "microbial self" thereby, connecting microbiome disease with autoimmunity. The hypothesis is based on simple principles. First, TcR are selected to avoid strong cross-reactivity with "self," resulting in selection for a TcR repertoire mimicking "genetic self." Second, evolution has selected for a "microbial self" that mimics "genetic self" so as to share tolerance. In consequence, our TcR repertoire also mimics microbiome antigenicity, providing a novel mechanism for modulating tolerance to it. Also, the microbiome mimics the TcR repertoire, acting as a secondary immune system. I call this TcR-microbiome mimicry "holoimmunity" to denote immune tolerance to the "holobiont self." Logically, microbiome-host mimicry means that autoimmunity directed at host antigens will also attack components of the microbiome, and conversely, an immunological attack on the microbiome may cross-react with host antigens producing "holoautoimmunity."

Clinical Utility of Biomarkers in IBD

There is no gold standard for the diagnosis and monitoring of inflammatory bowel diseases (IBD). Biomarkers are useful tools for the management of patients suffering from IBD. However, they should be used only when their additional information is useful for clinical decision-making. In principal, four situations during the management of an individual IBD patient can be discriminated from a clinical standpoint in which biomarkers provide useful information. First, biomarkers may be helpful when the diagnosis of IBD is established and aid in the discrimination between ulcerative colitis (UC) and Crohn's disease (CD) is necessary. Second, biomarkers may be helpful in the prognostic evaluation of IBD severity or disease behavior and for early decisions on the best treatment. The third situation in which biomarkers are useful is the evaluation of disease activity during the disease course, for monitoring and for guidance of ongoing treatment. Finally, the fourth typical situation when biomarkers are of value is after surgery to predict or diagnose a relapse of the disease. From a clinical point of view, it may be more useful to discuss specific biomarkers and their individual value and impact in these four prototypic situations than to sum up advantages and disadvantages for each biomarker isolated from the clinical situation. Therefore, this overview is structured in chapters reflecting those four typical situations during the disease course of IBD patents to critically evaluate the potential and value of each of the biomarkers in the specific situation.

The promise and pitfalls of serologic testing in inflammatory bowel disease

The role of IBD serologies is still evolving. However, as that evolution progresses, it will continue to provide important insights into the etiology of IBD and help define individualized treatment strategies for patients. The presence of multiple IBD antimicrobial antibodies and increased reactivity form a useful heuristic model to understand the evolution of CD. The role of ANCAs and autoantibodies in pathogenesis of UC is an area that requires further investigation. Although IBD serologies exhibit considerable diagnostic accuracy, it is unclear whether they will supplant simpler and more direct evaluations in making an initial diagnosis of UC or Crohn (Table 3). The utility of panels of IBD serologies to stratify and predict the course of CD has been an arena of fertile investigation. Developing individual treatment strategies based on the probability of developing complicated aggressive disease would be a significant advance in medical management of CD. However, if major clinical decisions are to be made based on these serologies, we will need more prospective critical studies from the time of diagnosis to define their clinical applicability and to demonstrate a true difference in outcomes.

Antibodies anti-Saccharomyces cerevisiae (ASCA) do not differentiate Crohn's disease from celiac disease

CONTEXT

Anti-Saccharomyces cerevisiae antibodies (ASCA), considered serologic markers for Crohn's disease, were described in patients with celiac disease, disappearing after a gluten-free diet.

OBJECTIVES

Evaluation of ASCA positivity in patients with Crohn's disease and celiac disease in relation to healthy individuals.

METHODS

A total of 145 individuals were studied: 36 with Crohn's disease and 52 with celiac disease, that fulfilled the diagnostic criteria for both affections, and 57 healthy individuals for control. The celiac patients were divided as follow: group CeD I at diagnosis (n = 34), group CeD II with gluten-free diet compliance (n = 13) and group CeD III with transgressions to the diet (n = 5). ASCA IgA and IgG were determined by ELISA.

RESULTS

With statistical significance, ASCA IgA were positive in Crohn's disease, celiac disease at diagnosis and celiac disease with diet transgressions; ASCA IgG in Crohn's disease and in all groups with celiac disease.

CONCLUSIONS

The detection of ASCA in patients with celiac disease allows to suggest that ASCA is not a specific marker for Crohn's disease, but was associated with the inflammation of the small intestine. The increased levels of positive ASCA may be due to genetic factors and increased intestinal permeability.

Diagnostic role and clinical association of ASCA and ANCA in Brazilian patients with inflammatory bowel disease

BACKGROUND

Anti-Saccharomyces cerevisae antibody (ASCA) and perinuclear anti-neutrophil cytoplasmatic antibody (pANCA) remain the most well-established markers in inflammatory bowel disease (IBD), and both may be associated with disease phenotype.

AIM

To determine the utility of ASCA and pANCA as markers in a Brazilian cohort of IBD patients.

MATERIALS AND METHODS

A total of 90 patients with ulcerative colitis (UC), 77 patients with Crohn's disease (CD), and 57 healthy individuals were included in the study. ASCA was determined by enzyme-linked immunosorbent assay (ELISA) and pANCA by immunofluorescence assay.

RESULTS

In support of diagnosis of UC, the sensitivity and specificity of pANCA were 51% and 100%, respectively. ASCA (IgA or IgG isotypes) presented sensitivity of 62% and specificity of 93% for CD. The combination of ASCA negativity and pANCA positivity (ASCA-/pANCA+) displayed sensitivity of 43% and specificity of 100% for diagnosis to UC. In CD patients, ASCA+/pANCA- presented sensitivity and specificity of 57% and 93%, respectively. Additionally, ASCA positivity correlated with early age at disease onset and ileal location in CD patients. In UC patients, pANCA positivity was correlated with pancolitis or left colitis.

CONCLUSIONS

The results evidenced that low sensitivity of ASCA and pANCA markers limits their use in IBD screening in the general population; however, their specificity may contribute to differentiation between CD and UC in IBD patients. Our study lends further support to the suggestion that serologic assessment identifies different subtypes of IBD.

Detection of Perinuclear Antineutrophil Cytoplasmic Antibodies and Antinuclear Antibodies in the Diagnosis of Canine Inflammatory Bowel Diseas

In recent years, serologic markers for diagnosis and classification of inflammatory bowel disease (IBD) have been used in human medicine. Perinuclear, antineutrophil, cytoplasmic antibodies (p-ANCA) are the most important of these markers. Because of their similar pattern of fluorescence, antinuclear antibodies (ANA) could cause misleading interpretations. The aim of the present study was to evaluate the use of an indirect fluorescent antibody test to detect p-ANCA in dogs with IBD, to compare the presence of p-ANCA in dogs with IBD with the presence of the same antibodies in other dogs, and to analyze the presence of ANAs in the p-ANCA-positive samples. Using a 1:10 dilution as a cutoff point, a sensitivity of 0.34 and a specificity of 0.86 was obtained when dogs with IBD were compared with the other groups as a whole, and specificity increased to 0.94 when dogs with IBD were compared with animals with other chronic gastrointestinal disorders. The lowest specificity value, 0.76, was obtained when the group of dogs with IBD was compared with that of dogs with different inflammatory and infectious disorders. Globally, 78 dogs were positive for p-ANCA when the cutoff was 1:10. Only 1 dog from these 78 animals was also seropositive to ANA. The results suggest that 1) detection of p-ANCA might be included in the IBD diagnostic protocol as another test to differentiate between this disease and other digestive diseases with similar clinical signs, and 2) most p-ANCA- positive dogs are not ANA positive.

The prevalence and diagnostic value of perinuclear antineutrophil cytoplasmic antibodies and anti-Saccharomyces cerevisiae antibodies in patients with inflammatory bowel disease in mainland China

BACKGROUND

Perinuclear anti-neutrophil cytoplasmic (pANCA) and anti-Saccharomyces cerevisiae antibodies (ASCA) have been studied extensively in Western countries. We determined the prevalence of pANCA and ASCA in the mainland Chinese population and the ability of pANCA and ASCA to discriminate between ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

Two hundred-six unrelated patients with IBD (UC, n=152; CD, n=54), 60 patients with other gastrointestinal diseases, and 80 healthy controls were included. Sera pANCA and ASCA titers were determined by a standardized indirect immunofluorescence technique.

RESULTS

The sensitivity, specificity, positive and negative predictive values, and positive likelihood ratio of pANCA were calculated for differentiating UC from healthy controls (43.4%, 96.3%, 95.7%, 47.2%, and 11.7, respectively) and ASCA for differentiating CD from healthy controls and (46.3%, 96.3%, 89.3%, 72.6%, and 12.5, respectively). The combination of pANCA and ASCA did not result in greater diagnostic efficiency than either test alone. pANCA was more frequent in UC with extensive or severe phenotype than others. ASCA was associated with severe CD disease activity.

CONCLUSIONS

pANCA and ASCA are useful in confirming the diagnosis of IBD and differentiating between UC and CD in an IBD cohort in central China.

The prevalence and clinical significance of perinuclear anti-neutrophil cytoplasmic antibody in Korean patients with ulcerative colitis

Perinuclear anti-neutrophil cytoplasmic antibody (pANCA) is a serological marker associated with various immune-mediated diseases whose clinical significance and possible diagnostic roles in ulcerative colitis (UC) are still unclear. We aimed to evaluate the prevalence of pANCA expression and its association with clinical findings and disease course in Korean patients with UC. This study included 484 patients with UC who were diagnosed and treated between 1990 and 2006 at Severance Hospital, Yonsei University, Seoul, Korea, and were followed for at least 1 year. Clinical findings at diagnosis, disease extent, treatment modalities used, and cumulative relapse rates were analyzed and compared to pANCA expression. Of the 484 patients, 405 (83.7%) were evaluated for pANCA and were eligible for analysis. The overall pANCA prevalence was 22.1%, with a female preponderance (male, 21.5%; female, 31.6%; P < 0.05). Proctitis was more common in pANCA-negative patients (pANCA-negative, 37.6%; pANCA-positive, 25.2%, P < 0.05). UC activity index and cumulative relapse rates were higher in pANCA-positive patients. However, there were no significant differences in the cumulative probability of steroid and immunosuppressant use and operation rate between the two groups. The prevalence of pANCA expression in Korean patients with UC was relatively low compared to that in Western countries. Although UC patients with pANCA expression had more severe clinical findings at diagnosis and higher cumulative relapse rates in our study, further prospective studies are warranted to clarify whether pANCA positivity influences the initial clinical presentation or disease aggressiveness.

Age of diagnosis influences serologic responses in children with Crohn's disease: a possible clue to etiology?

BACKGROUND

Crohn's disease (CD) is often associated with antibodies to microbial antigens. Differences in immune response may offer clues to the pathogenesis of the disease. The aim was to examine the influence of age at diagnosis on the serologic response in children with CD.

METHODS

Data were drawn from 3 North American multicenter pediatric inflammatory bowel disease (IBD) research consortia. At or shortly after diagnosis, pANCA, ASCA IgA, ASCA IgG, anti-ompC, and anti-CBir1 were assayed. The results were compared as a function of age at CD diagnosis (0-7 years versus 8-15 years).

RESULTS

In all, 705 children (79 <8 years of age at diagnosis, 626 >or=8 years) were studied. Small bowel CD was less frequent in the younger group (48.7% versus 72.6%; P < 0.0001), while colonic involvement was comparable (91.0% versus 86.5%). ASCA IgA and IgG were seen in <20% of those 0-7 years old compared to nearly 40% of those 8-15 years old (P < 0.001), while anti-CBir1 was more frequent in the younger children (66% versus 54%, P < 0.05). Anti-CBir1 detected a significant number of children in both age groups who otherwise were serologically negative. Both age at diagnosis and site of CD involvement were independently associated with expression of ASCA and anti-CBir1.

CONCLUSIONS

Compared to children 8-15 years of age at diagnosis, those 0-7 years are more likely to express anti-CBir1 but only half as likely to express ASCA. These age-associated differences in antimicrobial seropositivity suggest that there may be different, and as yet unrecognized, genetic, immunologic, and/or microbial factors leading to CD in the youngest children.

Diagnostics of inflammatory bowel disease

The diagnosis of inflammatory bowel disease (IBD) with its 2 main subforms, Crohn's disease and ulcerative colitis, is based on clinical, endoscopic, radiologic, and histologic criteria. This paradigm remains unchanged despite the advent of new molecular technologies for the examination of serum proteins and genetic sequences, respectively. The main innovations in diagnostic technologies include the development of more sophisticated endoscopic and noninvasive imaging techniques with the aim of improving the identification of complications, in particular malignant diseases associated with IBD. The future will see further progress in the identification of genetic susceptibility factors and of protein biomarkers and their use to describe the molecular epidemiology of IBD. It can be expected that future diagnostic algorithms will include molecular parameters to detect early disease or guide therapies by predicting the individual course of disease.

Update on Anti-Saccharomyces cerevisiae antibodies, anti-nuclear associated anti-neutrophil antibodies and antibodies to exocrine pancreas detected by indirect immunofluorescence as biomarkers in chronic inflammatory bowel diseases: Results of a multicenter study

AIM: Anti-Saccharomyces cerevisiae antibodies (ASCA), anti-nuclear associated anti-neutrophil antibodies (NANA) and antibodies to exocrine pancreas (PAB), are serological tools for discriminating Crohn’s disease (CrD) and ulcerative colitis (UC). Like CrD, coeliac disease (CoD) is an inflammatory bowel disease (IBD) associated with (auto) antibodies. Performing a multicenter study we primarily aimed to determine the performance of ASCA, NANA and PAB tests for IBD diagnosis in children and adults, and secondarily to evaluate the prevalence of these markers in CoD.

METHODS: Sera of 109 patients with CrD, 78 with UC, 45 with CoD and 50 healthy blood donors were retrospectively included. ASCA, NANA and PAB were detected by indirect immunofluorescence (IIF).

RESULTS: ASCA+/NANA- profile displayed a positive predictive value of 94.2% for CrD. Detection of ASCA was correlated with a more severe clinical profile of CrD and treatment of the disease did not influence their serum levels. ASCA positivity was found in 37.9% of active CoD. PAB were found in 36.7% CrD and 13.3% CoD patients and were not correlated with clinical features of CrD, except with an early onset of the disease. Fifteen CrD patients were ASCA negative and PAB positive.

CONCLUSION: ASCA and PAB detected by IIF are specific markers for CrD although their presence does not rule out a possible active CoD. The combination of ASCA, NANA and PAB tests improves the sensitivity of immunological markers for CrD. Repeating ASCA, NANA, and PAB testing during the course of CrD has no clinical value.

Management of inflammatory bowel diseases in Eastern Europe

Limited data are available on the management of inflammatory bowel diseases (IBD) in East European countries. The diagnostic tools and most treatment options are also available in Eastern Europe. The diagnostic procedures commonly used became more sophisticated in the past few years, with a greater use of computed tomography/magnetic resonance imaging and serology testing; however, double contrast barium enema, enteroclysis, and endoscopy remained standard. The medical therapy and surgical strategies are also somewhat different from those applied in Western countries. In ulcerative colitis, besides mesalazine, the use of sulphasalazine is still frequent, while azathioprine is only used in a minority of patients. The use of conventional corticosteroids is common and the rate of non-colorectal cancer associated colectomies is low. In contrast, 5-aminosalicylates are still used for maintenance in Crohn's disease and azathioprine is generally less frequently given compared with Western Europe. Biological agents have also become available about five years ago, yet their use is restricted mainly to specialised centres.

Diagnostic precision of anti-Saccharomyces cerevisiae antibodies and perinuclear antineutrophil cytoplasmic antibodies in inflammatory bowel disease

AIMS

The aim of this study was to assess the diagnostic precision of antiSaccharomyces cerevisiae (ASCA) and perinuclear antineutrophil cytoplasmic antibodies (pANCA) in inflammatory bowel disease (IBD) and evaluate their discriminative ability between ulcerative colitis (UC) and Crohn's disease (CD).

METHODS

Meta-analysis of studies reporting on ASCA and pANCA in IBD was performed. Sensitivity, specificity, and likelihood ratios (LR+, LR-) were calculated for different test combinations for CD, UC, and for IBD compared with controls. Meta-regression was used to analyze the effect of age, DNAse, colonic CD, and assay type.

RESULTS

Sixty studies comprising 3,841 UC and 4,019 CD patients were included. The ASCA+ with pANCA- test offered the best sensitivity for CD (54.6%) with 92.8% specificity and an area under the ROC (receiver operating characteristic) curve (AUC) of 0.85 (LR+ = 6.5, LR- = 0.5). Sensitivity and specificity of pANCA+ tests for UC were 55.3% and 88.5%, respectively (AUC of 0.82; LR+ = 4.5, LR- = 0.5). Sensitivity and specificity were improved to 70.3% and 93.4% in a pediatric subgroup when combined with an ASCA- test. Meta-regression analysis showed decreased diagnostic precision of ASCA for isolated colonic CD (RDOR = 0.3).

CONCLUSIONS

ASCA and pANCA testing are specific but not sensitive for CD and UC. It may be particularly useful for differentiating between CD and UC in the pediatric population.

Analysis of serum antibodies in patients suspected of having inflammatory bowel disease

Inflammatory bowel disease (IBD) is the general term used for a heterogeneous group of intestinal disorders, including Crohn's disease (CD) and ulcerative colitis (UC). Serological markers such as anti-Saccharomyces cerevisiae antibodies (ASCA) and atypical perinuclear antineutrophilic cytoplasmic antibody (atypical pANCA) have proven useful in the diagnosis and differentiation of CD and UC. Immunoglobulin A (IgA) antibody directed against the outer membrane protein C (OmpC) of Escherichia coli is said by one group to have clinical utility in diagnosing IBD, specifically in ASCA-negative CD patients. Our objective in this study was to compare the results obtained from two separate laboratories offering similar IBD tests using sera from suspected IBD patients. One hundred ninety-seven sera received for IBD testing were included in the study. The agreement between the two laboratories was 93.4% for ASCA IgA, 90.9% for ASCA IgG, and 87.8% for atypical pANCA IgG. There were 25 sera with ASCA-negative/OmpC-positive results reported by one laboratory. Thirteen of these 25 (52.0%) ASCA-negative/OmpC-positive sera were also atypical pANCA positive (9 as determined by both laboratories, 3 by one, and 1 by the other). Atypical pANCA antibody is found primarily in IBD patients with UC and colon-limited CD (Crohn's colitis). We conclude that the ASCA and atypical pANCA assays showed good agreement between the two laboratories, but the data for ASCA-negative/OmpC-positive sera suggest that many (52.0%) of these patients were more likely to have had UC or Crohn's colitis based on the presence of an atypical pANCA.

Antibodies to tissue-type plasminogen activator (t-PA) in patients with inflammatory bowel disease: high prevalence, interactions with functional domains of t-PA and possible implications in thrombosis

BACKGROUND

Patients with inflammatory bowel disease (IBD) have an increased prevalence of thromboembolic events. The pathogenetic mechanisms of these events include reduced fibrinolysis, which may be caused by antibodies to tissue-type plasminogen activator (t-PA).

OBJECTIVES

To evaluate anti-t-PA antibodies in patients with IBD, considering clinical, biochemical and functional characteristics.

PATIENTS AND METHODS

We immunoenzymatically measured anti-t-PA antibodies in plasma from 97 consecutive IBD patients and 97 age- and sex-matched healthy controls. We also assessed the antibody interactions with different epitopes of t-PA, the antibody inhibition on t-PA activity and the correlations with clinical features and other serum antibodies.

RESULTS

IBD patients had higher median anti-t-PA antibody levels (5.4 U mL(-1) vs. 4.0 U mL(-1); P < 0.0001): 18 patients were above the 95th percentile of the controls (OR 5.3; 95% CI 1.7-16.3; P < 0.003), and the six with a history of thrombosis tended to have high levels (6.9 U mL(-1)). Anti-t-PA antibody levels did not correlate with IBD type, activity, location or treatment, or with age, sex, acute-phase reactants or other antibodies. The anti-t-PA antibodies were frequently IgG1 and bound t-PA in fluid phase; they recognized the catalytic domain in 10 patients and the kringle-2 domain in six. The IgG fraction from the three patients with the highest anti-t-PA levels slightly reduced t-PA activity in vitro.

CONCLUSIONS

The prevalence of anti-t-PA antibodies is high in IBD patients. By binding the catalytic or kringle-2 domains of t-PA, these antibodies could lead to hypofibrinolysis and contribute to the prothrombotic state of IBD.

Anti-Saccharomyces cerevisiae and perinuclear anti-neutrophil cytoplasmic antibodies in coeliac disease before and after gluten-free diet

BACKGROUND

Anti-Saccharomyces cerevisiae and perinuclear anti-neutrophil cytoplasmic autoantibodies are markers of Crohn's disease and ulcerative colitis respectively.

AIM

To determine the prevalence of anti-S. cerevisiae and perinuclear anti-neutrophil cytoplasmic autoantibodies in a large series of coeliac disease patients before and after gluten free diet, and to correlate anti-S. cerevisiae-positivity with intestinal mucosal damage.

METHODS

One hundred and five consecutive coeliac disease patients and 141 controls (22 ulcerative colitis, 24 Crohn's disease, 30 primary sclerosing cholangitis, 15 postenteritis syndrome, 50 blood donors) were tested for anti-S. cerevisiae by enzyme-linked immunosorbent assay and for perinuclear anti-neutrophil cytoplasmic autoantibodies by indirect immunofluorescence.

RESULTS

In coeliac disease anti-S. cerevisiae (immunoglobulin G and/or immunoglobulin A) were slightly less frequent (59%) than in Crohn's disease (75%, P = 0.16) and significantly more frequent than in ulcerative colitis (27%), primary sclerosing cholangitis (30%), postenteritis syndrome (26%) and blood donors (4%) (P = 0.009, P = 0.0002, P = 0.025, P < 0.0001). No correlation was found between anti-S. cerevisiae and degree of mucosal damage. Perinuclear anti-neutrophil cytoplasmic autoantibodies were detected only in one coeliac. After gluten free diet the disappearance of anti-S. cerevisiae-immunoglobulin A (93%) was more frequent than that of immunoglobulin G (17%, P = 0.0001); perinuclear anti-neutrophil cytoplasmic autoantibodies disappeared in the only coeliac positive at diagnosis.

CONCLUSION

More than half of untreated coeliacs are anti-S. cerevisiae-positive irrespective of the severity of mucosal damage. Differently from immunoglobulin A, anti-S. cerevisiae-immunoglobulin G persisted in more than 80% after gluten free diet. The high prevalence of anti-S. cerevisiae in coeliac disease suggests that they may be the effect of a non-specific immune response in course of chronic small bowel disease.