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

Development and validation of diagnosis model for inflammatory bowel diseases based on a serologic biomarker panel: A decision tree model study

BACKGROUND AND STUDY AIMS

Currently, an increasing amount of experimental data is available on newly discovered biomarkers in inflammatory bowel diseases (IBD), but the role of these biomarkers is often questionable due to their limited sensitivity. Therefore, this study aimed to build a diagnostic tool incorporating a panel of serum biomarkers into a computational algorithm to identify patients with IBD and differentiate those with Crohn's disease (CD) from those with ulcerative colitis (UC).

PATIENTS AND METHODS

We studied sera from 192 CD patients, 118 UC patients, 60 non-IBD controls and 60 healthy controls. Indirect immunofluorescence (IIF) assays were utilized to determine several serum biomarkers previously associated with IBD, and the decision tree algorithm was used to construct the diagnosis model. Performances of models were evaluated by prediction accuracy, precision, AUC and Matthews's correlation coefficient (MCC). The "Inflammatory Bowel Disease Multi-omics Database (IBDMDB)" cohorts were used to validate the model as external validation set.

RESULTS

The prediction rates were determined and compared for decision tree models after each data was developed using C5.0, C&RT, QUEST and CHAID. The C5.0 and CHAID algorithms, which ranked top for the prediction rate in the IBD vs. non-IBD model and the CD vs. UC model, respectively, were utilized for final pattern analysis. The final decision tree model achieved higher classification accuracy than the approach based on conservative marker combinations (sensitivity 75.0% vs. 79.5%, specificity 93.8% vs. 78.3% for differentiating IBD from non-IBD; and sensitivity 84.3% vs. 73.4%, specificity 92.5% vs. 54.9% for differentiating CD from UC, respectively). The model prediction consistency was 93% (28/30) in the external validation set.

CONCLUSION

The decision-tree-based approach used in this study, based on serum biomarkers, has shown to be a valid and useful approach to identifying IBD and differentiating CD from UC.

Role of Serum Proteinase 3 Antineutrophil Cytoplasmic Antibodies in the Diagnosis, Evaluation of Disease Severity, and Clinical Course of Ulcerative Colitis

Background/Aims

Proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA) is a serologic marker for granulomatosis with polyangiitis. However, recent studies have also shown their role as diagnostic markers for ulcerative colitis (UC). This study was performed to investigate the clinical roles of PR3-ANCAs in the disease severity, disease extension, and clinical course of UC.

Methods

Serum PR3-ANCAs were measured in 173 UC patients including 77 patients with new-onset patients UC diagnosed within 1 month, 110 patients with Crohn’s disease, 48 patients with other intestinal diseases, and 71 healthy controls. Associations between the PR3-ANCA titer and clinical data, such as disease severity, disease extension, and clinical course, were assessed. The clinical utility of PR3-ANCA measurement was evaluated by receiver operating characteristic (ROC) analysis.

Results

PR3-ANCA ≥3.5 U/mL demonstrated 44.5% sensitivity and 95.6% specificity for the diagnosis of UC in all patients. PR3-ANCA positivity was more prevalent in the 77 new-onset UC patients (58.4%). In this group, the disease severity and extension were more severe in PR3-ANCA positive patients than in PR3-ANCA negative group (p<0.001). After treatment, the partial Mayo scores were significantly decreased with the PR3-ANCA titers. The proportion of patients who required steroids for induction therapy was significantly higher among PR3-ANCA positive than negative group. ROC analysis revealed that PR3-ANCA ≥3.5 U/mL had 75% sensitivity and 69.0% specificity for steroid requirement in new-onset UC patients.

Conclusions

Our results indicate that PR3-ANCA measurement is useful not only for diagnosing UC but also for evaluating disease severity and extension and predicting the clinical course.

The Role of Biomarkers in Surgery for Ulcerative Colitis: A Review

Ulcerative colitis (UC) is an inflammatory condition that generally affects the rectum and extends proximally into the colon in a continuous, distal-to-proximal pattern. Surgical resection (total proctocolectomy) is the only cure for UC and is often necessary in managing complicated or refractory disease. However, recent advances in biologically targeted therapies have resulted in improved disease control, and surgery is required in only a fraction of cases. This ever-increasing array of options for medical management has added complexity to surgical decision-making. In some circumstances, the added time required to ensure failure of medical therapy can delay colectomy in patients who will ultimately need it. Indeed, many patients with severe disease undergo trials of multiple medical therapies prior to considering surgery. In severe cases of UC, continued medical management has been associated with a delay to surgical intervention and higher rates of morbidity and mortality. Biomarkers represent a burgeoning field of research, particularly in inflammatory bowel disease and cancer. This review seeks to highlight the different possible settings for surgery in UC and the role various biomarkers might play in each.

Anti-neutrophil cytoplasmic antibody testing by indirect immunofluorescence: Computer-aided versus conventional microscopic evaluation of routine diagnostic samples from patients with vasculitis or other inflammatory diseases

BACKGROUND

Detection of anti-neutrophil cytoplasmic antibodies (ANCA) by indirect immunofluorescence assays (IFA) is of diagnostic importance in vasculitides and some other inflammatory diseases. Automation of IFA may be beneficial in high-throughput clinical laboratories. An analytical appraisal of the EUROPattern (EPa) automated microscope and image analysis system has not been reported in a routine clinical laboratory setting testing samples from both vasculitis and non-vasculitis patients.

METHODS

Results of EPa and on-screen ANCA pattern recognition of 568 consecutive routine serum samples were compared to those of conventional visual evaluation.

RESULTS

Agreement of discrimination between negative and non-negative samples was 86.1% comparing EPa and conventional reading, and it increased to 96.7% after on-screen user validation. Importantly, from the 334 samples classified as negative by EPa 328 (98.2%) were also negative by conventional evaluation. Pattern recognition showed 'moderate' agreement between classical microscopic and EPa analysis (κ = 0.446) and 'very good' agreement after user validation (κ = 0.900). Misclassification by EPa was dominantly due to the presence of anti-nuclear/cytoplasmic antibodies (incorrect pattern, 80/568) and the lower fluorescence cut-off of the automated microscope (false positives, 73/568).

CONCLUSIONS

Automated ANCA testing by EPa is a reliable alternative of classical microscopic evaluation, though classification of sera needs correction by trained personnel during on-screen validation.

Ulcerative Colitis in Hematological Malignancies: Paraneoplastic Manifestation or Coincidental Bystander?

Evidence of coexistence of diverse hematological malignancies—lymphoma, leukemia, multiple myeloma, and myelodysplastic syndromes—and either ulcerative colitis or Crohn's disease can be found in the literature. However, a more “systemic” effort to reach further and examine the potential of either one as paraneoplastic manifestation has not been performed. Based on these, three cases of ulcerative colitis manifesting before, simultaneously, and after the onset of different hematological malignancies are presented and critically evaluated.

Serological antibodies and surgery in a population-based inception cohort of Crohn's disease patients - the IBSEN study

Introduction: Serological antibodies have been associated with complicated disease course in Crohn's disease (CD), including the need for surgery.Aim: The aim of this study was to investigate if a panel of relevant antibodies could predict surgery in a prospective population-based cohort of patients with CD.Methods: The population-based IBSEN cohort has been followed prospectively for 20 years. At the 10- and 20-year follow-up, the following panel of serological antibodies was analysed: pANCA, ASCA IgA, ASCA IgG, anti-OmpC, anti-I2, and anti-CBir1. At the 20-year follow-up or until lost to follow-up, all CD-related surgeries were registered.Results: Serum was available from 159 patients at 10-year follow-up and 135 patients at 20-year follow-up. In 113 patients, serum was available at both time points. No significant change of antibody status (positive vs. negative) was found from 10-year to 20-year follow-up. Negative pANCA, positive ASCA IgA and positive ASCA IgG at 10-year follow-up were all individually associated with increased risk for CD-related surgery. There was no association between anti-OmpC, anti-I2 or anti-CBir1 and CD-related surgery. In a multiple regression model including disease location and behaviour, only stricturing or penetrating disease behaviour and negative pANCA remained significantly associated with higher odds for surgery.Conclusion: Positive ASCA IgA and IgG, and negative pANCA were associated with higher odds for CD-related surgery in univariate analysis. Since disease phenotype changes during the disease course, while serological antibodies are stable, our results support the use of pANCA, ASCA IgA and ASCA IgG as prognostic markers in CD.

Epidemiology and Clinical Outcomes of Inflammatory Bowel Disease: A Hospital-Based Study in Central Taiwan

The incidence and prevalence of inflammatory bowel disease (IBD) are low but increasing in Taiwan. We aimed to investigate the epidemiology and clinical outcomes of IBD in central Taiwan. We retrospectively analyzed patients with IBD diagnosed at our hospital between January 2000 and September 2018. The diagnostic criteria were based on endoscopic and pathologic findings. Clinical characteristics, treatment regimens, and treatment outcomes were analyzed. A total of 190 patients with IBD were enrolled (80 with Crohn's disease (CD) and 110 with ulcerative colitis (UC)). The mean age at diagnosis was 38.4 years (CD: 36 years, UC: 40 years). Male patients accounted for the majority of patients (71.1%). The male-to-female ratio was 3 : 1 for CD and 2.1 : 1 for UC. Current and ever smokers accounted for 30.5% of all patients. Only 4.2% of patients had a family history of IBD. Extraintestinal manifestations (EIMs) were reported in 7.9%, and colorectal cancers (CRCs) were reported in 2.1% of all patients. In patients with CD, the ileal type was the most common disease phenotype (57.5%), and the stricturing type was the most common disease behavior (60.0%). In patients with UC, left-sided colitis was the predominant disease extent (42.7%). The seroprevalence of hepatitis B virus (HBV) was 13.3%. The incidence of perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA) in patients with UC was 22%. 5-Aminosalicylic acids were the preferred treatment for UC, whereas corticosteroids, immunomodulators, and biologic agents were preferred for CD. In patients with CD, the bowel resection rate was 38.8%, and the incidence of hip avascular necrosis was 3.8%. In Taiwan, patients with IBD showed a male predominance, lack of familial clustering, a higher prevalence of HBV infection, and a lower prevalence of p-ANCA, EIMs, and CRC. Moreover, a higher incidence of the ileal type with poor outcomes of CD and left-sided predominance in UC were found.

Serologic testing of a panel of five antibodies in inflammatory bowel diseases: Diagnostic value and correlation with disease phenotype

The aim of the present study was to evaluate the diagnostic value of five serological antibodies, perinuclear antineutrophil cytoplasmic antibody (pANCA), anti-Saccharomyces cerevisiae antibodies [ASCA; ASCA-immunoglobulin (IgG)and ASCA-IgA], Escherichia coli outer membrane porin C antibody (anti-OmpC) and CBir1 flagellin antibody for detection in inflammatory bowel diseases. Whether the antibody status correlated with the disease phenotype was also evaluated. Sera from 71 patients with Crohn's disease (CD), 41 patients with ulcerative colitis (UC), 78 patients with other gastrointestinal diseases and 31 healthy control subjects were investigated. Clinical data were gathered at the time of serum sampling and enzyme-linked immunosorbent assay was used to determine titers of the above mentioned five antibodies. The pANCA test exhibited a sensitivity of 53.7% for UC and the ASCA test had a sensitivity of 66.2% for CD. The prevalence of anti-OmpC was significantly higher in CD than in intestinal tuberculosis (TB), indicating that anti-OmpC may be a serologic marker distinguishing CD from TB. The pANCA⁺/ASCA- exhibited the best specificity for differentiating between CD and UC. In UC, the presence of pANCA was greater in the patients with moderate to severe activity than in those with mild activity. ASCA was more positive in ileal CD. Furthermore, positive ASCA-IgG or anti-OmpC implied that complicated CD and pANCA was associated with colonic CD. Seropositivity of anti-CBir1 was lowest in colonic CD.

TNFAIP6 is a potential biomarker of disease activity in inflammatory bowel disease

AIM

Ideal biomarkers are needed for evaluating the activity of inflammatory bowel disease (IBD). We aimed to investigate the value of TNFAIP6 as a biomarker.

MATERIALS & METHODS

Inflamed colonic samples and serum samples were collected from patients with Crohn's disease (CD), patients with ulcerative colitis (UC), and normal controls. SPSS 18.0 was used for statistical analysis.

RESULTS

Serum TNFAIP6 was higher in IBD patients than in normal controls and correlated with the inflammatory indicators. Compared with active patients, TNFAIP6 was decreased in both CD and UC patients in remission. Furthermore, TNFAIP6 concentrations consistent with TNF-α level, correlated well with disease location and extent of both CD and UC.

CONCLUSION

Serum TNFAIP6 may be a promising biomarker for evaluating the disease activity of IBD, demonstrating the diagnostic value in disease location differentiation.

Asia Pacific Consensus Statements on Crohn's disease. Part 1: Definition, diagnosis, and epidemiology: (Asia Pacific Crohn's Disease Consensus--Part 1)

Inflammatory bowel disease (IBD) was previously thought to be rare in Asia, but emerging data indicate rising incidence and prevalence of IBD in the region. The Asia Pacific Working Group on Inflammatory Bowel Disease was established in Cebu, Philippines, at the Asia Pacific Digestive Week conference in 2006 under the auspices of the Asian Pacific Association of Gastroenterology with the goal of developing best management practices, coordinating research, and raising awareness of IBD in the region. The consensus group previously published recommendations for the diagnosis and management of ulcerative colitis with specific relevance to the Asia-Pacific region. The present consensus statements were developed following a similar process to address the epidemiology, diagnosis, and management of Crohn's disease. The goals of these statements are to pool the pertinent literature specifically highlighting relevant data and conditions in the Asia-Pacific region relating to the economy, health systems, background infectious diseases, differential diagnoses, and treatment availability. It does not intend to be all comprehensive and future revisions are likely to be required in this ever-changing field.

Diagnostic Potential of Zymogen Granule Glycoprotein 2 Antibodies as Serologic Biomarkers in Chinese Patients With Crohn Disease

The need for reliable biomarkers for distinguishing Crohn disease (CD) from ulcerative colitis (UC) is increasing. This study aimed at evaluating the diagnostic potential of anti-GP2 antibodies as a biomarker in Chinese patients with CD. In addition, a variety of autoantibodies, including anti-saccharomyces cerevisiae antibodies (ASCA), perinuclear anti-neutrophil cytoplasmic antibodies (PANCA), anti-intestinal goblet cell autoantibodies (GAB), and anti-pancreatic autoantibodies (PAB), were evaluated.A total of 91 subjects were prospectively enrolled in this study, including 35 patients with CD, 35 patients with UC, 13 patients with non-IBD gastrointestinal diseases as disease controls (non-IBD DC), and 8 healthy controls (HC). The diagnosis of IBD was determined based on the Lennard-Jones criteria, and the clinical phenotypes of the IBD patients were determined based on the Montreal Classification.Anti-GP2 IgG antibodies were significantly elevated in patients with CD, compared with patients with UC (P = 0.0038), HC (P = 0.0055), and non-IBD DC (P = 0.0063). The prevalence of anti-GP2 IgG, anti-GP2 IgA and anti-GP2 IgA, or IgG antibodies in patients with CD was 40.0%, 37.1%, and 54.3%, respectively, which were higher than those in non-IBD DC (anti-GP2 IgG, 15.4%; anti-GP2 IgA, 7.7%; and anti-GP2 IgA or IgG, 23.1%) and those in patients with UC (anti-GP2 IgG, 11.4%; anti-GP2 IgA, 2.9%; and anti-GP2 IgA or IgG, 14.3%). For distinguishing CD from UC, the sensitivity, specificity, positive predictive value (PPV) and positive likelihood ratios (LR+) were 40%, 88.6%, 77.8%, and 3.51 for anti-GP2 IgG, 37.1%, 97.1%, 92.9%, and 13.0 for anti-GP2 IgA, and 54.3%, 85.3%, 79.2%, and 3.69 for anti-GP2 IgA or IgG. For CD diagnosis, the combination of anti-GP2 antibodies with ASCA IgA increased the sensitivity to 68.6% with moderate loss of specificity to 74.3%. Spearman's rank of order revealed a significantly positive correlation of anti-GP2 IgG with ileocolonic location of disease (L3) (P = 0.043) and a negative correlation of anti-GP2 IgA with biologic therapy (P = 0.012).Our findings suggest that anti-GP2 antibodies could serve as a biomarker for distinguishing patients with CD from patients with UC, and the combination of anti-GP2 antibodies with ASCA IgA may improve the predictive power.

Overcoming difficulty in diagnosis and differential diagnosis of Crohn's disease: the potential role of serological and genetic tests

Crohn's disease (CD) represents a heterogeneous group of chronic inflammatory disorders with various phenotypes. Establishing a definite diagnosis of CD should be based upon a combined assessment of clinical, endoscopic, radiological and pathological features. Although segmental disease distribution, transmural inflammation and non-caseating epithelioid granulomas have been considered as a 'hallmarks' for CD, clear diagnosis of CD in some patients has been challenging, due to overlapping endoscopic, radiographic and histologic features with other inflammatory bowel disease-like conditions. Laboratory markers (serological and genetic tests) may provide additional clues for the diagnosis and differential diagnosis of CD. This review focuses on the application of the currently available serological and genomic markers and in diagnosis and differential diagnosis of CD.

Clinical aspects of indirect immunofluorescence for autoimmune diseases

Because the most common term used in conversations considering autoimmunity is autoantibodies, it is well-expected that the indirect immunofluorescence assay, which detects antibodies directed against various antigens, is one of our most impressive techniques for investigating autoimmune diseases (AIDs). Roughly speaking, the current literature corroborates that this immunopathologic investigation means that autoantibodies detection makes a considerable contribution to both diagnostic and prognostic aspects of AIDs in the clinical setting. However, it varies between different AIDs, autoantibodies, ethnicities or detection methodologies. Directly focusing on the indirect immunofluorescence assay, we present evidence to support this multidimensional variation regarding the subject via reviewing briefly the best-investigated autoantibodies in the well-documented AIDs, including vasculitis, inflammatory bowel disease, scleroderma, autoimmune hepatitis, primary biliary cirrhosis, systemic lupus erythematosus and Sjögren's syndrome.

Expression of high mobility group box 1 protein in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory condition of the colon which involves a complex interplay of genetic, immunological and environmental factors. The precise pathogenesis of UC remains unclear till now. The high mobility group box 1 (HMGB1) protein is a nuclear non-histone DNA-binding protein that is present within the nuclei of almost all eukaryotic cells. Recent studies indicate that HMGB1 can be released into the extracellular milieu and mediate inflammatory response, thereby contributing to the pathogenesis of numerous infectious and noninfectious, inflammatory and autoimmune diseases, as well as cancers. Many studies have indicated that HMGB1 is involved in the development of UC. The present paper gives an overview of HMGB1 and UC.

Association of HLA-DRB1 alleles and anti-neutrophil cytoplasmic antibodies in Han and Uyghur patients with ulcerative colitis in China

OBJECTIVE

We aimed to study the association between HLA-DRB1 alleles and anti-neutrophil cytoplasmic antibodies (ANCA) among Uyghur and Han patients with ulcerative colitis (UC) in China.

METHODS

Altogether 160 UC patients and 466 healthy controls of Uyghur and Han groups residing in the Xinjiang Uyghur Autonomous Region of China were included. HLA-DRB1 variants were identified from genomic DNA using polymerase chain reaction and gene sequencing. Serum ANCA were determined by indirect immunofluorescence assay.

RESULTS

Among the Uyghur populations, the HLA-DRB1*08 gene frequency was lower in the UC patients than in the control group (P = 0.012, OR 0.12, 95% CI 0.02-0.91); however, that of HLA-DRB1*13 was much higher in the UC patients than in the controls (P = 0.001, OR 4.32, 95% CI 1.92-9.74). In Han patients with UC, there was no significant difference in HLA-DRB1 frequency between UC patients and healthy controls. The positive rate of ANCA in Uyghur patients with UC was significantly higher than in Han UC patients (P = 0.026), and ANCA positivity was associated with an increased frequency of HLA-DRB1*13 in Uyghur UC patients, but no such difference was observed in the Han patients.

CONCLUSIONS

Genetic polymorphisms of the HLA-DRB1*08 and *13 may contribute to the clinical heterogeneity of UC between Uyghur and Han UC patients in China. In Uyghur UC patients, HLA-DRB1*13 may be correlated with ANCA positivity.

Biomarkers of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic disease mostly involved with intestine with unknown etiology. Diagnosis, evaluation of severity, and prognosis are still present as challenges for physicians. An ideal biomarker with the characters such as simple, easy to perform, noninvasive or microinvasive, cheap, rapid, and reproducible is helpful for patients and clinicians. Currently biomarkers applied in clinic include CRP, ESR, pANCA, ASCA, and fecal calprotectin. However, they are far from ideal. Lots of studies are focused on seeking for ideal biomarker for IBD. Herein, the paper reviewed recent researches on biomarkers of IBD to get advances of biomarkers in inflammatory bowel disease.

Combining TNFSF15 and ASCA IgA can be used as a predictor for the stenosis/perforating phenotype of Crohn's disease

BACKGROUND AND AIM

Focusing on TNFSF15 instead of NOD2, we set out to evaluate whether combining serologic and genetic markers could distinguish between Crohn’s disease (CD) and ulcerative colitis (UC), and whether they could be used to stratify the disease behavior of Taiwanese CD patients.

METHODS

Clinical information, serum isolation, and DNA were collected after obtaining informed consent. The serological markers were analyzed by ELISA kits and the genetic analysis for TNFSF15 single-nucleotide polymorphisms (SNPs) by Sequenom. Statistic analyses were conducted by SAS 9.2 (Cary, NC, USA).

RESULTS

This study included 108 patients (55 CD, 53 UC) and 60 healthy controls. An initial low positive rate and low sensitivity for the serological markers led us to reset the cut-off values. This reset cut-off for ASCA IgA yielded a sensitivity of 0.291 and specificity of 0.925 for differentiating CD from UC patients. The reset cut-off value for p-ANCA (anti-MPO) had a sensitivity of 0.461 and a specificity of 0.817 for differentiating inflammatory bowel disease patients from healthy controls. Among the TNFSF15 SNPs, rs4263839 associated with CD in Taiwan (P = 0.005), haplotype analysis did not increase the association. Combining the genetic marker TNFSF15 (rs4263839) and serological marker ASCA IgA increased the area under the curve from 0.61 to 0.70 for predicting stenosis/perforating phenotype, compared to ASCA IgA alone.

CONCLUSIONS

Serological markers need to be tested and tailored to different countries/ethnicities. Combining the genetic marker TNFSF15 with ASCA IgA increased the power of predicting stenosis/perforating phenotype in CD patients with TNFSF15 but not with a NOD2 genetic background.

Anti-Saccharomyces cerevisiae antibodies associate with phenotypes and higher risk for surgery in Crohn's disease: a meta-analysis

BACKGROUND

Recent studies suggested that anti-Saccharomyces cerevisiae antibody (ASCA) status was associated with diagnostic findings, stratified classification phenotypes, disease activity and clinical course of Crohn's disease (CD). However, the relationship between ASCA status and phenotypes of CD remains controversial in these studies.

AIMS

The purpose of this study was to evaluate whether ASCA status is associated with the phenotypes and the risk of surgery in diverse populations in CD.

METHODS

We conducted a meta-analysis of studies assessing the association of ASCA status with phenotypes and risk of surgery in CD. Three independent reviewers undertook data extraction. We pooled odds ratios separately for the cohort and case-control studies.

RESULTS

We identified ten cohort studies (n = 2,365) and 14 case-control studies (n = 1,887) that investigated the association of ASCA status with phenotypes and risk of surgery in CD. The meta-analysis of the cohort studies showed significant association between the ASCA-positive status and higher risk of early-onset age (OR 2.25, 95 % CI 1.41-3.57, P < 0.001), ileal involvement disease (1.70, 1.05-2.77, P = 0.03), complicated disease behavior (2.09, 1.71-2.57, P < 0.001), perianal disease (1.49, 1.14-1.94, P = 0.004), and risk for surgery (1.61, 1.29-2.01, P < 0.001). Meta-analysis of the case-control studies also showed a significantly higher risk in ileal involvement disease (1.77, 1.25-2.49, P = 0.001), complicated disease behavior (2.13, 1.70-2.68, P < 0.001), perianal disease (1.96, 1.38-2.78, P < 0.001), and risk for surgery (1.71, 1.17-2.49, P = 0.005), except for the early-onset age (1.16, 0.80-1.69, P = 0.44).

CONCLUSIONS

This meta-analysis indicated that positive ASCA status is a risk factor for early-onset age, ileal involvement, complicated behavior, perianal disease and requirement for surgery in CD.

Autoantibodies to GP2, the major zymogen granule membrane glycoprotein, are new markers in Crohn's disease

BACKGROUND

Crohn's disease (CD) is an inflammatory bowel disease (IBD) characterized by reactivity against microbial and self antigens. Zymogen granule glycoprotein 2 (GP2) was identified as the major autoantigen of CD-specific pancreatic autoantibodies (PAB).

METHODS

Human GP2 was expressed in the Spodoptera frugiperda 9 (Sf9) cell line using the baculovirus system, purified by Ni-chelate chromatography, and used as antigen for anti-GP2 IgA and IgG assessment by enzyme-linked immunosorbent assays (ELISA). Antibodies to mannan of Saccharomyces cerevisiae (ASCA), PAB, and anti-GP2 were investigated in sera of 178 CD patients, 100 ulcerative colitis (UC) patients, and 162 blood donors (BD).

RESULTS

Anti-GP2 IgG and IgA were found in 48/72 (66.7%) and 23/72 (31.9%) PAB positive and 5/106 (4.7%) and 1/106 (0.9%) PAB negative CD patients (p<0.0001), respectively. CD patients displayed significantly higher reactivity to GP2 than UC patients and BD (p<0.0001), respectively. Occurrence of anti-GP2 antibodies correlated with PAB reactivity (Spearmen's rho=0.493, p<0.00001). There was a significant relationship between the occurrence of ASCA IgG and anti-GP2 IgG (p=0.0307).

CONCLUSIONS

Anti-GP2 IgG and IgA constitute novel CD specific autoantibodies, the quantification of which could improve the serological diagnosis of IBD.