Anti-cardiolipin and anti-beta 2-glycoprotein I antibodies in celiac disease.

AIMS: To determine the frequency of anti-cardiolipin (aCL) and anti-ß2-glycoprotein I antibodies (aß2GPI) in celiac disease (CD) patients. PATIENTS AND METHODS: Sixty-three untreated CD patients and 40 healthy blood donors (HBD) were studied. IgG, IgA and IgM aCL and aß2GPI were detected by Elisa. RESULTS: The frequency of antiphospholipid antibodies (aPL) (aCL and/or aß2GPI) was significantly higher in CD patients (12 out of 63) than in HBD (two out of 40) (19% vs 5%, P=0.04). Six CD patients out of 63 (9.5%) and one HBD out of 40 (2.5%) had aCL. Ten CD patients (15.9%) and two HBD (5%) had aß2GPI. Only aß2GPI-IgA was significantly more frequent in CD patients than in HBD (14.3% vs 2.5%, P=0.048). In CD patients, aß2GPI-IgA (nine out of 63) was significantly more frequent (14.3%) than aß2GPI-IgG (1.6%) and IgM (1.6%) (P=0.008). In CD patients, the frequency of aCL-IgA and IgM was 6.3% (four out of 63) and aCL-IgG were not detected. Simultaneous presence of positive antibodies was found in four CD patients: one patient had four aPL, one had three aPL and two had two aPL. The four patients who had aCL-IgA had also aß2GPI-IgA and three of them had a titer higher than 50 units. Among nine patients with aß2GPI-IgA, four had a titer higher than 100 units. The highest titers were found in adults. CONCLUSIONS: aPL and particularly aß2GPI-IgA are frequent in CD. The significance of these antibodies has to be determined.

IgA anti-actin antibodies in celiac disease.

AIMS: The purpose of this study was to determine the sensitivity and specificity of IgA anti-actin antibodies (IgA-AAA) for celiac disease (CD), to investigate their usefulness as a marker of compliance in CD patients to the gluten-free diet (GFD), and to assess the relationship between their presence in the sera of CD patients and severity of intestinal mucosal damage. PATIENTS AND METHODS: A total of 182 patients with CD were studied: 63 patients were untreated; 50 patients were following a strict GFD; and 69 patients were non-compliant with a GFD. IgA-AAA was detected using a homemade enzyme-linked immunosorbent assay (ELISA). RESULTS: IgA-AAA showed a sensitivity of 41.3% and a specificity of 71.4% for a diagnosis of CD. In children, the frequency of IgA-AAA detection was lower in those following a strict GFD (23.1%) compared with untreated patients (39.4%) and those not complying with a GFD (32.5%). In patients following a strict GFD, IgA-AAA detection was significantly less frequent in children than in adults (23.1% vs. 58.3%, respectively; P<0.001). IgA-AAA was found in 17 out of 52 CD patients with total villous atrophy (32.7%), and in one out of 11 patients with subtotal villous atrophy (9%). CONCLUSION: IgA-AAA cannot replace anti-endomysium and anti-tissue transglutaminase antibodies in the diagnosis algorithm of CD, but it can serve as a reliable marker of severe intestinal mucosal damage in CD patients.

Detection of M2 antimitochondrial antibodies by dot blot assay is more specific than by enzyme linked immunosorbent assay.

AIMS: The objective of our study was, in one hand, to determine the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of ELISA and dot blot assay to investigate IgG M2 antimitochondrial antibodies (M2 AMA) and, on the other hand, to compare these results with those of indirect immunofluorescence technique (IIF). METHODS: Sera from patients suffering from primary biliary cirrhosis (PBC) (n=55), systemic lupus erythematosus (n=21), celiac disease (n=30) and blood donors (n=75) were analyzed. M2 AMA were detected by ELISA and dot blot using pyruvate dehydrogenase purified from porcine heart and by IIF on cryostat sections of rat liver-kidney-stomach. RESULTS: IIF was more sensitive (98%) than ELISA (93%) and dot blot (91%). The specificity of AMA for PBC using IIF, ELISA and dot blot reached 100%, 92% and 100%, respectively. The PPV of IIF, ELISA and dot blot was 100%, 93% and 100%, respectively. The NPV was 98% for IIF, 92% for ELISA and 91% for dot blot. CONCLUSION: Dot blot, using purified pyruvate dehydrogenase, had a higher specificity than ELISA and may be useful in confirming the specificity of AMA in cases of doubt with IIF.

B cell-ablative therapy: where are we now?

Based on their multifaceted functions, B cells participate in several pathological settings such as lymphoproliferative disorders, autoimmune diseases and graft rejection. B cell-ablative therapy has thus emerged as a mainstay in these diseases. A number of anti-B cell antibodies (Abs) have been generated, among which anti-CD20 Abs appear to be efficient. Rituximab (RTX) is one of these anti-CD20 monoclonal Abs. Originally approved for the treatment of non-Hodgkin lymphoma, RTX is now being administered in other malignant proliferations, applied to an increasing number of autoimmune diseases and required to prevent rejection of a graft. Although this medication is remarkably safe, a handful of laboratory tests have been proposed to monitor RTX-treated patients. The efficacy in different diseases, and the emergence of new anti-CD20 Abs raise many questions. Thus, their detailed understanding can lead to a better issue for inhibition of immune responses.

[Antihistones antibodies in systemic lupus erythematosus, comparison of three assays: Elisa, dot blot and immunoblot]. / Anticorps antihistones au cours du lupus érythémateux systémique, comparaison entre trois techniques: Elisa, dot blot et immunotransfert.

AIMS: The purpose of our study is to determine and compare the sensitivity of an enzyme linked immunosorbent assay (ELISA), a dot blot assay and an immunoblot assay for the detection of the IgG class antihistones antibodies in a population of systemic lupus erythematosus. The correlation between antihistones antibodies and the main clinical features of SLE or between antihistones antibodies and the presence of anti-double-stranded-DNA antibodies were analysed. MATERIALS AND METHODS: Serum samples from 126 systemic lupus erythematosus patients, classified according to the criteria of the American College of Rheumatology, were analysed for the presence of antihistones antibodies using a dot blot assay and an ELISA. Antihistones subfractions antibodies were assessed using the immunoblot technique on 88 out of the 126 sera. Serum samples from 50 blood-donors were analyzed as negative controls. RESULTS: The sensitivity of antihistones antibodies assessed by dot blot assay and ELISA was 69% and 54% respectively, and was lower than that of anti-double-stranded-DNA antibodies (83%). The sensitivity of the immunoblot assay for the detection of antihistones antibodies was 72%. Incidence of autoantibodies against histones H1, H2 A, H2B, H3 and H4 was 60%, 53%, 48%, 36% and 29.5% respectively. We found a correlation between the presence of antihistones antibodies, detected by the dot blot assay and ELISA, and the presence of anti-double-stranded-DNA antibodies. Antihistones antibodies detected by ELISA were correlated with renal disease in systemic lupus erythematosus; they showed a specificity, a positive and a negative predictive value for renal disease in systemic lupus erythematosus higher than those of anti-double-stranded-DNA antibodies. CONCLUSIONS: The sensitivity of the dot blot assay for the detection of antihistones antibodies is better than that of ELISA, but the latter technique could detect some cases negative by ELISA. Antihistones antibodies detected by ELISA have an important predictive value in the renal complications in systemic lupus erythematosus, better than that of AdsDNA. Antibodies to histone H1 were the most frequent antihistones autoandibodies in systemic lupus erythematosus and they were highly correlated with anti-double-stranded-DNA antibodies and renal disease.

Celiac disease in Tunisia: serological screening in healthy blood donors.

BACKGROUND: Recent epidemiological studies in Europe and in USA using antigliadin antibodies and antiendomysium antibodies for initial screening have shown that the overall prevalence of celiac disease (CD) is about 1:200 (0.5%). AIM: To screen for CD in healthy blood donors in Tunisia. PATIENTS AND METHODS: Sera from 2500 healthy blood donors (median age: 21 years, 70% men and 30% women) were screened for IgG-antigliadin antibodies and IgA-antigliadin antibodies with an enzyme-linked immunosorbent assay. All sera with positive antigliadin antibodies were tested for antiendomysium antibodies using human umbilical cord cryosections as substrate. RESULTS: Seven healthy blood donors (median age: 21 years; four men, three women) have antiendomysium antibodies. The prevalence of antiendomysium antibodies in healthy blood donors in Tunisia is 1:355 (0.28%). CONCLUSIONS: On the basis of a high specificity of the antiendomysium antibodies, it is likely that the seven blood donors identified in this study have CD. These data suggest that CD is frequent in Tunisia.

Tissue transglutaminase antibodies in celiac disease, comparison of an enzyme linked immunosorbent assay and a dot blot assay.

AIMS: The purpose of our study is to determine the sensitivity, specificity and predictive values of an enzyme linked immunosorbent assay (ELISA) and a dot blot assay for the detection of IgA class anti-tissue transglutaminase antibodies (IgA-AtTGA) and to compare these results with those of IgA class anti-endomysium antibodies (IgA-AEA), IgA class anti-reticulin antibodies (IgA-ARA) and IgA class anti-gliadin antibodies (IgA-AGA). PATIENTS: Serum samples from 143 patients (97 children, 46 adults) with untreated celiac disease (CD) confirmed by intestinal biopsy and 74 disease controls (64 children, 10 adults) were studied. Methods. - The anti-tissue transglutaminase antibodies were detected by dot blot assay and an ELISA using guinea pig tissue transglutaminase (gp-tTG) as antigen. The anti-endomysium antibodies were detected by an indirect immunofluorescence technique on cryostat sections of human umbilical cord. The anti-reticulin antibodies were also investigated by indirect immunofluorescence on cryostat sections of kidney, liver and stomach of rat. The anti-gliadin antibodies were determined by an ELISA. RESULTS: The sensitivity of an ELISA for the detection of anti-tissue transglutaminase antibodies was 86% in children and 87% in adults and the sensitivity of dot blot assay was 57% in children and 54% in adults. The specificity of an ELISA and dot blot for the detection for anti-tissue transglutaminase antibodies was, respectively, 96% and 88% lower than that of anti-endomysium antibodies (100%). The sensitivity of anti-gliadin antibodies was 97% in children and 91% in adults and their specificity was 85%. The sensitivity of anti-reticulin antibodies was 94% in children and 87% in adults. Their specificity was 100%. CONCLUSIONS: The sensitivity and specificity of an ELISA for the detection of anti-tissue transglutaminase antibodies were better than that of dot blot assay. However, this dot blot assay could screen four celiac patients who have not had anti-tissue transglutaminase antibodies by an ELISA. The sensitivity of anti-endomysium antibodies was better than that of anti-tissue transglutaminase antibodies, anti-reticulin antibodies and anti-gliadin antibodies but in children aged less than 2 years, the sensitivity of anti-gliadin antibodies was better than that of anti-tissue transglutaminase antibodies.