Rediscovery of the Anti-Pancreatic Antibodies and Evaluation of their Prognostic Value in a Prospective Clinical Cohort of Crohn's Patients: The Importance of Specific Target Antigens [GP2 and CUZD1].

BACKGROUNDS Glycoprotein 2[GP2] and CUB zona pellucida-like domain 1[CUZD1] belong to protein families involved in gut innate immunity processes and have recently been identified as specific targets of anti-pancreatic autoantibodies [PAbs] in Crohn's disease[CD]. We aimed to determine the prognostic potential of novel target-specific PAbs regarding long-term disease course of an adult CD patient cohort. METHODS Sera of 458 consecutive well-characterised IBD patients from a single referral IBD centre were tested by enzyme-linked immunosorbent assay [ELISA] with isoform 4 of recombinant GP2 [anti-MZGP2 and anti-GP2 IgA/IgG] and indirect immunofluorescence test [IIFT] system with GP2 and CUZD1 expressing transfected HEK 293 cells [anti-rPAg2 and rPAg1 IgA/IgG]. Clinical data were available on complicated disease or surgical interventions as well as disease activity and medical treatment during the prospective follow-up [median, 108 months]. RESULTS Totals of 12.4% and 20.8% of CD patients were positive for IgA/IgG type of anti-GP2 and anti-CUZD1, respectively, with a significant difference compared with UC [p < 0.01]. Antibody status was stable over time. Agreement among three different anti-GP2 assays was good. Positivity for PAbs, mainly IgA subtypes, predicted a faster progression towards complicated disease course. In Kaplan-Meier analysis, time to surgery or development of perianal disease was associated with anti-GP2 IgA [pLogRank < 0.01] or anti-CUZD1 IgA [pLogRank < 0.001] positivity, respectively. Anti-CUZD1 IgA remained an independent predictor in the multivariate Cox-regression model (hazard ratio [HR]: 3.43, 95% confidence interval [CI]: 1.68-7.02, p < 0.001). CONCLUSIONS The present study has shown that specific PAbs [especially IgA subtype] predict complicated disease course including the development of perianal disease in CD

Prevalence estimation of celiac disease in the general adult population of Latvia using serology and HLA genotyping

BACKGROUND: Prevalence estimates for celiac disease (CD) depend on the method used. The role of deamidated gliadin peptide (DGP) and genetic testing in epidemiological studies and diagnostic settings of celiac disease (CD) has still to be established. OBJECTIVES: The objective of this article is to assess the prevalence of CD in Latvia by combining serological tests with DQ2.5/DQ8 testing. METHODS: A total of 1444 adults from a randomly selected cross-sectional general population sample were tested by ELISA for tTG IgA, DGP IgA and IgG antibodies (QUANTA Lite®, Inova Diagnostics Inc). Samples with tTG IgA ≥20U were tested for EMA IgA by indirect immunofluorescence assay, and all specimens with tTG IgA ≥15U were tested by QUANTA-Flash® chemiluminescent assays (CIA) (Inova Diagnostics Inc) for tTG IgA, DGP IgA and IgG. DQ2.5/8 was detected in individuals with any positive ELISA test and a subgroup of controls. RESULTS: Forty-three individuals (2.98%; 95% CI: 2.10–3.86%) tested positive by at least one ELISA test; 41.86% of the serology-positive individuals (any test above the cutoff) were DQ positive. Six individuals (0.42%; 95% CI: 0.09–0.75%) were triple ELISA positive, and DQ2.5 or DQ8 was positive in all; 0.35% (95% CI: 0.05–0.65%) were tTG IgA and EMA positive. Two tTG IgA-negative cases were both DGP IgG and IgA positive, both being DQ positive; including them in the “serology-positive” group would increase the prevalence to 0.49% (95% CI: 0.13–0.85%). CIA tests revealed 2 tTG IgA-positive and EMA-negative cases with a positive genotype. DQ2.5 or DQ8 genotype was positive in 28.6% of the serology-negative population. CONCLUSIONS: Estimates of the prevalence of CD in Latvia based on the serogenetic testing approach range from 0.35% to 0.49% depending on the criteria used. There is a rationale for combining serological tests and DQ2.5/8 genotyping

Prevalence, significance and predictive value of antiphospholipid antibodies in Crohn's disease

AIM To assess the prevalence and stability of different antiphospholipid antibodies (APLAs) and their association with disease phenotype and progression in inflammatory bowel diseases (IBD) patients. METHODS About 458 consecutive patients [Crohn's disease (CD): 271 and ulcerative colitis (UC): 187] were enrolled into a follow-up cohort study in a tertiary IBD referral center in Hungary. Detailed clinical phenotypes were determined at enrollment by reviewing the patients' medical charts. Disease activity, medical treatment and data about evolvement of complications or surgical interventions were determined prospectively during the follow-up. Disease course (development f complicated disease phenotype and need for surgery), occurrence of thrombotic events, actual state of disease activity according to clinical, laboratory and endoscopic scores and accurate treatment regime were recorded during the follow-up, (median, 57.4 and 61.6 mo for CD and UC). Sera of IBD patients and 103 healthy controls (HC) were tested on individual anti-β2-Glycoprotein-I (anti-β2-GPI IgA/M/G), anti-cardiolipin (ACA IgA/M/G) and anti-phosphatidylserine/prothrombin (anti-PS/PT IgA/M/G) antibodies and also anti-Saccharomyces cerevisiae antibodies (ASCA IgA/G) by enzyme-linked immunosorbent assay (ELISA). In a subgroup of CD (n = 198) and UC patients (n = 103), obtaining consecutive samples over various arbitrary time-points during the disease course, we evaluated the intraindividual stability of the APLA status. Additionally, we provide an overview of studies, performed so far, in which significance of APLAs in IBD were assessed. RESULTS Patients with CD had significantly higher prevalence of both ACA (23.4%) and anti-PS/PT (20.4%) antibodies than UC (4.8%, P < 0.0001 and 10.2%, P = 0.004) and HC (2.9%, P < 0.0001 and 15.5%, P = NS). No difference was found for the prevalence of anti-β2-GPI between different groups (7.2%-9.7%). In CD, no association was found between APLA and ASCA status of the patients. Occurrence of anti-β2-GPI, ACA and anti-PS/PT was not different between the group of patients with active vs inactive disease state according to appropriate clinical, laboratory and endoscopic scores in CD as well as in UC patients. All subtypes of anti-β2-GPI and ACA IgM status were found to be very stable over time, in contrast ACA IgG and even more ACA IgA status showed significant intraindividual changes. Changes in antibody status were more remarkable in CD than UC (ACA IgA: 49.9% vs 23.3% and ACA IgG: 21.2% vs 5.8%). Interestingly, 59.1% and 30.1% of CD patients who received anti-TNF therapy showed significant negative to positive changes in ACA IgA and IgG antibody status respectively. APLA status was not associated with the clinical phenotype at diagnosis or during follow-up, medical therapy, or thrombotic events and it was not associated with the probability of developing complicated disease phenotype or surgery in a Kaplan-Meier analysis. CONCLUSION The present study demonstrated enhanced formation of APLAs in CD patients. However, presence of different APLAs were not associated with the clinical phenotype or disease course

The diagnostic value of anti-parietal cell and intrinsic factor antibodies, pepsinogens, and gastrin-17 in corpus-restricted atrophic gastritis

Raksta tekstā kļuda: afilācijai "Digestive Diseases Centre GASTRO Ltd", norādīta atrašanas vieta: Hong Kong, ChinapublishersversionPeer reviewe

Presence of Anti-Microbial Antibodies in Liver Cirrhosis – A Tell-Tale Sign of Compromised Immunity?

Bacterial translocation plays important role in the complications of liver cirrhosis. Antibody formation against various microbial antigens is common in Crohn's disease and considered to be caused by sustained exposure to gut microflora constituents. We hypothesized that anti-microbial antibodies are present in patients with liver cirrhosis and may be associated with the development of bacterial infections.<0.001, OR:2.02) by Cox-regression analysis.The present study suggests that systemic reactivity to microbial components reflects compromised mucosal immunity in patients with liver cirrhosis, further supporting the possible role of bacterial translocation in the formation of anti-microbial antibodies

Diagnostic and clinical significance of Crohn’s disease-specific anti-MZGP2 pancreatic antibodies by a novel ELISA:New anti-MZGP2 ELISA in Crohn’s

The recent identification of the pancreas major zymogen granule membrane glycoprotein 2 (MZGP2) as the major autoantigen of pancreatic autoantibody (PAB) has led to the appreciation of anti-MZGP2 antibodies as specific markers of Crohn’s disease (CrD). We have recently developed new, robust, highly sensitive and specific IgA and IgG anti-MZGP2 antibody ELISAs and assessed their clinical relevance in the largest inflammatory bowel disease (IBD) cohort tested to date for anti-MZGP2 antibodies. In contrast to currently available anti-MZGP2 ELISAs, the new QUANTA Lite® MZGP2 ELISA (INOVA Diagnostics, San Diego, CA) utilizes the eukaryotically-expressed specific isoform 4 of human GP2 UniProtKB: P55259. A total of 832 sera were studied including 617 consecutive IBD patients (323 CrD and 294 UC) under regular follow-up in a tertiary centre, 112 patients with various diseases, and 103 healthy blood donors. The new ELISA’s calculated AUC was 0.5968, 95% CI (0.5552, 0.6383) for IgA anti-MZGP2 [CD vs non-CD (UC plus controls)] and 0.6236, 95% CI (0.5813, 0.6659) for IgG anti-MZGP2. The sensitivity of IgA anti-MZGP2 for CrD in the IBD population was 15% and the specificity was 98% (95, 99), while the sensitivity and specificity of IgG anti-MZGP2 was 27% and 97%. IgA and IgG anti-MZGP2 combined testing led to a sensitivity of 31% and specificity of 96%. Positivity for either ASCA (IgA or IgG) or anti-MZGP2 (IgA or IgG) showed a sensitivity of 75% (70, 80) and specificity of 84% (79, 89). Of clinical relevance, IgA anti- MZGP2 antibodies were more prevalent in patients with early disease onset (Montreal classification A1, p=0.011), while patients with localised colonic disease were less likely to be IgG anti-MZGP2 positive. Anti-MZGP2 positive patients more frequently had extensive disease with ileal involvement and stricture formation. Patients with longer disease duration were more likely to have IgG anti-MZGP2 or IgA ASCA antibodies. In conclusion, the new IgA and IgG anti-MZGP2 antibody ELISAs allow accurate autoantibody determination, and can be used as a tool to study the clinical significance and utility of these autoantibodies in patients with IBD

Gut barrier failure biomarkers are associated with poor disease outcome in patients with primary sclerosing cholangitis

AIM To assess the prevalence of a panel of serologic markers that reflect gut barrier dysfunction in a mixed cohort of pediatric and adult primary sclerosing cholangitis (PSC) patients. METHODS Sera of 67 PSC patients [median age (range): 32 (5-79) years, concomitant IBD: 67% and cirrhosis: 20%] were assayed for the presence of antibodies against to F-actin (AAA IgA/IgG) and gliadin (AGA IgA/IgG)] and for serum level of intestinal fatty acid-binding protein (I-FABP) by ELISA. Markers of lipopolysaccharide (LPS) exposure [LPS binding protein (LBP)] and various antimicrobial antibodies [anti-OMP Plus IgA and endotoxin core IgA antibody (EndoCAb)] were also determined. Poor disease outcome was defined as orthotopic liver transplantation and/or liver-related death during the follow-up [median: 99 (14-106) mo]. One hundred and fifty-three healthy subjects (HCONT) and 172 ulcerative colitis (UC) patients were the controls. RESULTS A total of 28.4%, 28.0%, 9% and 20.9% of PSC patients were positive for AAA IgA, AAA IgG, AGA IgA and AGA IgG, respectively. Frequencies of AAA IgA and AAA IgG ( P < 0.001, for both) and AGA IgG ( P = 0.01, for both) but not AGA IgA were significantly higher compared to both of the HCONT and the UC groups. In survival analysis, AAA IgA-positivity was revealed as an independent predictor of poor disease outcome after adjusting either for the presence of cirrhosis [HR = 5.15 (1.27-20.86), P = 0.022 or for the Mayo risk score (HR = 4.24 (0.99-18.21), P = 0.052]. AAA IgA-positivity was significantly associated with higher frequency of antimicrobial antibodies ( P < 0.001 for EndoCab IgA and P = 0.012 for anti-OMP Plus IgA) and higher level of the enterocyte damage marker (median I-FABPAAA IgA pos vs neg: 365 vs 166 pg/mL, P = 0.011), but not with serum LBP level. CONCLUSION Presence of IgA type AAA identified PSC patients with progressive disease. Moreover, it is associated with enhanced mucosal immune response to various microbial antigens and enterocyte damage further highlighting the importance of the gut-liver interaction in PSC

Reassessment of Intrinsic Factor and Parietal Cell Autoantibodies in Atrophic Gastritis With Respect to Cobalamin Deficiency

OBJECTIVES: Atrophic body gastritis (ABG) is an autoimmune condition eventually manifesting itself as pernicious anemia (PA). Parietal cell autoantibodies (PCAs) and intrinsic factor autoantibodies (IFAs) are considered characteristics of these conditions. Recent studies on IFA and PCA frequency with respect to cobalamin deficiency in biopsy-proven ABG patients are lacking. We addressed this issue using new enzyme-linked immunosorbent assay (ELISA)-based assays. METHODS: Sera from 165 patients with histologically diagnosed ABG and 113 controls were tested for IFA and PCA using ELISA. A total of 81 ABG patients had cobalamin deficiency and macrocytic anemia (Group 1-PA), 36 had cobalamin deficiency without macrocytic anemia (Group 2), and 48 had normal cobalamin levels (Group 3). RESULTS: IFAs were detected in 44/165 ABG patients (27% sensitivity) and in 0/113 controls (100% specificity). PCAs were detected in 134 ABG patients (81% sensitivity) and in 11 controls (90% specificity). In Group 1, IFAs showed 37% sensitivity and 100% specificity, whereas PCAs showed 81% sensitivity and 90% specificity. Combining IFA and PCA testing increased the sensitivity to 61% in all ABG patients and to 73% in Group 1, while maintaining 100% specificity. CONCLUSIONS: IFAs are 100% specific for biopsy-proven ABG and occurred in 27% of patients. PCAs occurred in 81% of ABG patients and in 10% of controls. Combining IFA and PCA testing significantly increases their diagnostic performance for ABG and PA, yielding a 73% sensitivity for PA. The non-invasive combined PCA and IFA assessment may be useful in selecting patients at risk for autoimmune gastritis to be confirmed by gastroscopic-histologic examination

Comparative analysis of different enzyme immunoassays for assessment of phosphatidylserine-dependent antiprothrombin antibodies

Phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT) were strongly correlated with the presence of lupus anticoagulant showing a high specificity for the diagnosis of antiphospholipid syndrome. However, the main criticism for the clinical applicability of aPS/PT testing is the lack of reproducibility of the results among laboratories. In this study, we measured IgG and IgM aPS/PT using our original in-house enzyme-linked immunosorbent assays (ELISA) and commercial ELISA kits to assess the assay performance and to evaluate the accuracy of aPS/PT results. The study included 111 plasma samples collected from patients and stored at our laboratory for aPS/PT assessment. Sixty-one samples were tested for IgG aPS/PT using two assays: (1) aPS/PT in-house ELISA and (2) QUANTA Lite (TM) aPS/PT IgG ELISA kit (INOVA Diagnostics, Inc., USA). Fifty samples were evaluated for IgM aPS/PT using two assays: (1) aPS/PT in-house ELISA and (2) QUANTA Lite (TM) aPS/PT IgM ELISA kit (INOVA Diagnostics). Ninety-eight percent of samples yielded concordant results for IgG aPS/PT and 82 % for IgM aPS/PT. There was an excellent agreement between the IgG aPS/PT assays (Cohen kappa = 0.962) and moderate agreement between the IgM aPS/PT assays (kappa = 0.597). Statistically significant correlations in the aPS/PT results were obtained from both IgG and IgM aPS/PT assays (r = 0.749, r = 0.622, p < 0.001, respectively). In conclusion, IgG and IgM detection by ELISA is accurate. The performance of aPS/PT is reliable, and concordant results can be obtained using different ELISA methods