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.
Objective To investigate the prevalence of primary biliary cirrhosis (PBC) and PBC-associated autoantibodies in Japanese systemic sclerosis (SSc) patients. Methods Clinical data from 225 Japanese SSc patients were retrospectively obtained. Serum samples from these patients were examined for PBC-associated autoantibodies, anti-mitochondrial M2 antibodies (AMA), anti-sp100 antibodies (anti-sp100), and anti-gp210 antibodies (anti-gp210) by enzyme-linked immunosorbent assay. Results Of 225 patients, 37 (16.4%) had AMA, 13 (5.8%) had anti-sp100, and 3 (1.3%) had anti-gp210. Three patients were positive for both AMA and anti-sp100, and 2 were positive for both AMA and anti-gp210. PBC was found in 22 (9.8%) patients positive for AMA with or without anti-sp100 or anti-gp210, but not in those with anti-sp100 or anti-gp210 without AMA. Furthermore, 13 patients lacking these three antibodies were diagnosed with or suspected of PBC by liver biopsy and/or their clinical manifestation. Multivariable analysis revealed that AMA and anti-centromere antibodies were independently associated with PBC in SSc patients, while anti-sp100 and anti-gp210 were not. Conclusions This study has demonstrated even higher prevalence of both PBC-associated autoantibodies and PBC in the Japanese SSc population than in the Caucasian SSc population. AMA and anti-centromere antibodies are likely to indicate increasing risk of PBC in SSc patients.
Objective. To investigate the validity of the global APS score (GAPSS) to predict thrombosis in patients with autoimmune diseases. Methods. This prospective cohort study included consecutive patients with aPL or SLE. aPL, aPS-PT and GAPSS were determined. A Cox proportional hazards model assessed the validity of GAPSS and identified other potential independent predictors of thrombosis. Results. One hundred and thirty-seven patients [43.5 (s.d. 15.4) years old; 107 women] were followed up for a mean duration of 43.1 (s.d. 20.7) months. Mean GAPSS was significantly higher in patients who experienced a thrombotic event compared with those without [10.88 (s.d. 5.06) vs 8.15 (s.d. 5.31), respectively, P = 0.038]. In univariate analysis, age [hazard ratio (HR) = 1.04 (95% CI 1.01, 1.08)] and GAPSS above 16 [HR = 6.86 (95% CI 1.90, 24.77)] were each significantly associated with thrombosis during follow-up, while history of arterial thrombosis [HR = 2.61 (95% CI 0.87, 7.82)] failed to reach significance. Among aPL assays, IgG aPS/PT—a component of the GAPSS—was significantly associated with thrombosis [HR = 2.95 (95% CI 1.02, 8.51)]. In multivariate analysis, GAPSS above 16 remained the only significant predictor of thrombosis [HR = 6.17 (95% CI 1.70, 22.40)]. Conclusion. This first external validation study confirmed that GAPSS can predict thrombosis in patients with aPL and associated autoimmune diseases.
Summary Background Primary sclerosing cholangitis (PSC) is associated with progressive liver disease and cholangiocarcinoma. Although risk stratification is crucial for making clinical decisions, it is hindered by a scarcity of proven prognostic markers. Aims To assess the value of novel anti‐glycoprotein 2 (anti‐GP2) and anti‐neutrophil cytoplasmic antibodies to serine proteinase 3 (PR3‐ANCA) in combination with PSC‐specific clinical and laboratory markers as predictors of quality of life, disease severity, and cholangiocarcinoma in two large, independent cohorts of PSC patients Methods Discovery (338 Polish patients) and validation (178 German patients) cohorts with PSC were evaluated. Anti‐GP2 (isoforms 1/4) was detected by ELISAs and PR3‐ANCA by chemiluminescence immunoassay. Clinical and laboratory data were collected and analysed. The outcome was defined as liver transplantation‐free survival and occurrence of cholangiocarcinoma during follow‐up. Results In the discovery group, anti‐GP2 1/4 IgA and PR3‐ANCA were associated with liver dysfunction, anti‐GP2 1/4 IgA with risk scores for PSC and anti‐GP2 4 IgA with cirrhosis. All cholangiocarcinoma patients were positive for PR3‐ANCA and/or anti‐GP2 4 IgA. The association between anti‐GP2 IgA and liver biochemistry, risk scores, cirrhosis, impaired survival, and cholangiocarcinoma was confirmed in the validation cohort. Cox proportional‐hazards regression indicated anti‐GP2 1 IgA as an independent variable of poor outcome in both study cohorts. Analysis of the combined data showed that anti‐GP2 4 IgA and PR3‐ANCA were independent predictors for cholangiocarcinoma, while anti‐GP2 1 IgA and PR3‐ANCA were indicators for poor survival. Conclusions Anti‐GP2 and PR3‐ANCA are prognostic antibodies in PSC as they identify patients at risk of severe disease, poor survival and biliary cancer.
Objective. Currently, 3 antiphospholipid assays are widely used clinically [lupus anticoagulant (LAC), anticardiolipin (aCL), and anti-ß 2 -glycoprotein I (anti-ß 2 -GPI)]. LAC is the most specific assay, conferring the highest risk of thrombosis and pregnancy loss, but it cannot be validly performed in an anticoagulated patient. We investigated the usefulness of antiphosphatidylserine/prothrombin (anti-PS/PT) and its association with thrombosis. Anti-PS/PT is strongly associated with the presence of LAC. We also studied the association of IgA antiphospholipid isotypes and specific domains of ß 2 -GPI with thrombosis in systemic lupus erythematosus (SLE). Methods. Stored samples from patients with SLE, with and without past thrombosis, were assayed for antibodies to the whole ß 2 -GPI protein (IgG/IgM/IgA), to ß 2 -GPI domain 1 (IgG), to ß 2 -GPI domain 4/5 (IgA), aCL (IgG/IgM/IgA), and anti-PS/PT (IgG, IgM, and IgG/M). LAC was detected using the dilute Russell’s viper venom time (dRVVT) with confirmatory testing. Results. Anti-PS/PT IgG and IgG/M and anti-ß 2 -GPI IgG, IgM, and IgA were highly associated with a history of LAC by dRVVT (p < 0.0001). For all thrombosis, of the traditional ELISA assays, anti-ß 2 -GPI IgA, IgG, and aCL IgA were most associated. Anti-PS/PT IgG and IgG/M had a similar magnitude of association to the traditional ELISA. For venous thrombosis, of the traditional ELISA, anti-ß 2 -GPI (IgG and IgA), anti-PS/PT (IgG and IgG/M), and aCL IgA were associated. Again, anti-PS/PT (IgG and IgG/M) had the same magnitude of association as the traditional ELISA. For stroke, significant association was seen with anti-ß 2 -GPI IgA D4/5. Conclusion. In anticoagulated patients, where LAC testing is not valid, anti-PS/PT, either IgG or IgG/IgM, might serve as useful alternative tests to predict a higher risk of thrombosis. Anti-PS/PT antibodies were associated with all thrombosis and with venous thrombosis. IgA isotypes in secondary antiphospholipid syndrome are associated with thrombosis. Anti-ß 2 -glycoprotein domain 1 was not shown to be associated with thrombosis in SLE.
Antibodies directed against Saccharomyces cerevisiae (ASCA), perinuclear components of neutrophils (pANCA), and porin protein C of Escherichia coli (anti-OmpC) are reported to be associated with disease phenotype and may be of diagnostic importance in inflammatory bowel disease (IBD). Since limited data are available from Eastern Europe, we assessed the above antibodies in Hungarian IBD patients.In all, 653 well-characterized, unrelated consecutive IBD patients (Crohn's disease [CD]: 558, m/f: 263/295, duration: 8.1 +/- 10.7 years; ulcerative colitis [UC]: 95, m/f: 44/51, duration: 8.9 +/- 9.8 years) and 100 healthy subjects were investigated. Sera were assayed for anti-Omp and ASCA by enzyme-linked immunosorbent assay (ELISA) and ANCA by indirect immunofluorescence assay (IIF). TLR4 and NOD2/CARD15 variants were tested by polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP). Detailed clinical phenotypes were determined by reviewing the medical charts.Anti-Omp, ASCA, and atypical pANCA antibodies were present in 31.2%, 59.3%, and 13.8% of CD, 24.2%, 13.7%, and 48.5% of UC patients, and in 20%, 16%, and 5.6% of controls, respectively. ASCA and anti-Omp positivity were associated with increased risk for CD (odds ratio [OR](ASCA) = 7.65, 95% confidence interval [CI]: 4.37-13.4; OR(Omp) = 1.81, 95% CI: 1.08-3.05). In a logistic regression analysis, anti-Omp and ASCA were independently associated with ileal and noninflammatory disease, but not with a risk for surgery or response to steroids or infliximab. A serology dosage effect was also observed. ASCA and anti-Omp antibodies were associated with NOD2/CARD15, in addition to a gene dosage effect. No associations were found in UC.Serological markers were useful in the differentiation between CD and UC in an Eastern European IBD cohort. Reactivity to microbial components was associated with disease phenotype and NOD2/CARD15 genotype, further supporting the role of altered microbial sensing in the pathogenesis of CD.
Aims: Despite methodological difficulties, perinuclear antineutrophil cytoplasmic antibody (P-ANCA) is often screened in IBD patients for its clinical value. The antigen specificity of this atypical P-ANCA is different from the vasculitis associated classic P-ANCA, but the distinction of the two patterns on ethanol-fixed neutrophil substrate by indirect immunofluorescence (IIF) is difficult. Patients and methods: We analyzed the usefulness of applying formaldehyde-fixed neutrophils adding to ethanol-fixed ones in the detection of atypical P-ANCA in 204 IBD patients (CD: 111, UC: 96). Furthermore, we determined the reproducibility, interassay- and interobserver variability of both fixation methods comparing four different commercially available assays (INOVA Diagnostics, IMMCO Diagnostics, Euroimmun Labordiagnostika and Immunoconcepts) in two distinct laboratories. We also added myeloperoxidase (MPO), proteinase 3 (PR3), elastase, lactoferrin, cathepsin G, lysosyme and bactericidal permeability-increasing protein ELISAs (Orgentec) to the IIF. Results: Atypical P-ANCA was detected in 41.1% of patients with UC and 16% with CD. 75.0% and 78.4% of all the detected ANCA positivity was atypical P-ANCA in patients with UC and CD, respectively. The occurrences of classic P-ANCA and C-ANCA pattern were insignificant (1.3–9.5%). On the basis of κ-values, the differences among the commercially available substrates for ANCA detection were remarkable. Better agreement was found in the interobserver study. Conclusions: The IBD associated atypical P-ANCA pattern is most reliably differentiated by testing sera on both ethanol and formalin-fixed neutrophil slides. However, it is technically demanding, subjective, and requires experienced observers for good interpretation. Not all ANCA assays are suitable for the detection of these antibodies and the use of MPO, PR3 and other ELISAs may be unnecessary.
