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C Johanet

Publications and source records attributed to C Johanet.

At least 37 records · Page 2Linked to original sources
PubMed1996

Specificity and sensitivity of gp210 autoantibodies detected using an enzyme-linked immunosorbent assay and a synthetic polypeptide in the diagnosis of primary biliary cirrhosis.

Between 10% and 42% of patients with primary biliary cirrhosis (PBC) have been reported to have autoantibodies directed against a restricted epitope of gp210, a glycoprotein of the nuclear pore membrane. The prevalence and specificity of these antibodies was studied in a French series of 285 patients with PBC and 497 control individuals affected with other liver or autoimmune diseases. Sera were analyzed by an enzyme-linked immunosorbent assay (ELISA) that used a synthetic polypeptide containing the predominant autoepitope of gp210, in parallel to immunoblotting of gp210 protein and immunofluorescence microscopy. Autoantibodies to the gp210 epitope detected by ELISA were 25.5% sensitive and 99.5% specific for the diagnosis of PBC. These results were in agreement with a 99.4% specificity with immunoblotting analysis and a 96.6% specificity with immunofluorescence. In a subset of PBC patients without detectable antimitochondrial autoantibodies (AMA), gp210 autoantibodies were found in 7 of 15 patients (47%). Therefore, gp210 autoantibodies are highly specific for PBC and may be of particular utility in assessing patients without AMA or with other atypical presentations.

Amino Acid Sequence↗
PubMed1996

Antineutrophil cytoplasmic autoantibodies in autoimmune liver and inflammatory bowel diseases.

Perinuclear antineutrophil cytoplasmic autoantibodies have been described in inflammatory bowel diseases and in primary sclerosing cholangitis. Because the data concerning their occurrence are conflicting, we have used indirect immunofluorescence on ethanol-fixed neutrophils to test the sera from a large population of 382 patients with various liver and digestive diseases: in particular, from 27 patients with primary sclerosing cholangitis, 105 patients with autoimmune chronic active hepatitis, 30 patients with primary biliary cirrhosis and 124 patients with inflammatory bowel disease. The prevalence of the perinuclear antineutrophil cytoplasmic autoantibodies was 37% in ulcerative colitis and 15% in Crohn's disease. They would not be helpful in the differential diagnosis between these two inflammatory bowel diseases. Within the group of autoimmune liver diseases, perinuclear antineutrophil cytoplasmic autoantibodies were detected in 44% of sera from patients with primary sclerosing cholangitis and in 36% of sera from patients with type I autoimmune active hepatitis, but not in primary biliary cirrhosis. When primary sclerosing cholangitis was associated with an inflammatory bowel disease, the prevalence of these autoantibodies was 60%. They were 88% specific for primary sclerosing cholangitis and 86% specific for type I autoimmune active hepatitis. Despite their moderate sensitivity and specificity in primary sclerosing cholangitis, they remain the only serologic marker of this autoimmune liver disease. Moreover, they turned out to be a more sensitive marker for inflammatory bowel disease with associated primary sclerosing cholangitis.

Adolescent↗
PubMed1996

Antimitochondrial antibodies in patients with chronic hepatitis C.

Although autoantibodies have been found in the serum of patients with chronic hepatitis C virus (HCV) there has been no convincing evidence of the presence of antimitochondrial antibodies, until now. Sera from 460 untreated patients with chronic hepatitis C were tested for antimitochondrial antibodies, using an indirect immunofluorescence technique; and if they tested positive for the antibodies (titer more than 1:50), they also were treated by Western blot analysis. Seven (1.5%) sera were positive. None of the patients had biological or histological evidence of primary biliary cirrhosis. Antimitochondrial antibodies recognized one of the oxo-dehydrogenase multienzyme complexe's epitopes by Western blot assay in three patients only. All seven patients were then treated by interferon alpha for six months. None showed exacerbation of liver disease during treatment. HCV-RNA disappeared from the serum in one patient who became negative for anti-M2 antibodies. The four patients who did not respond to interferon-alpha therapy, and the two who relapsed after treatment withdrawal, had sustained positive antimitochondrial antibodies. These data suggest that: 1) antimitochondrial antibodies present in patients with chronic hepatitis C do not always recognize the same epitopes as in primary biliary cirrhosis; 2) these antibodies may disappear after eradication of HCV, suggesting that the production of antimitochondrial antibodies is linked to the presence of the virus and 3) the clinical and biological course of chronic hepatitis C, and the response to interferon-alpha therapy, does not seem to be different in patients who are positive for antimitochondrial antibodies.

3-Methyl-2-Oxobutanoate Dehydrogenase (Lipoamide)↗
PubMed1996

[Comparative study of serological markers for intolerance to gluten].

In France as well as in most of the other European countries, the prevalence of coeliac disease is underestimated. In order to point out a good screening test, we have determined the most sensitive combination (technique-marker) for the diagnosis of the disease among 81 individuals (50 with coeliac disease and 31 controls). Serum anti-gliadin antibodies were measured using three methods: the qualitative dot-blot (Gliastick-Eurospital) and two quantitative methods Elisa (homemade-Saint-Antoine Hospital and alpha-Gliatest-Eurospital); serum anti-endomysium antibodies (EmA) and anti-reticulin antibodies (ARA) were detected using an indirect immunofluorescence assay. We have shown that the simple and fast Gliastick test can fulfil the selected criterion with a sensitivity of 0.90. Nevertheless, uncertain and positives results have to be confirmed by one of the two more specific quantitative tests. The two other markers (ARA and EmA) have shown a better specificity (1) but they were less sensitive (0.54 and 0.56 for ARA and EmA respectively). Thus, they have both to be used as confirmation tests and for follow-up with supervision of the compliance to recommended diet. In conclusion, the Gliastick can be considered as a good screening test for the detection of anti-gliadin antibodies and it would represent the expected help to determine the prevalence of coeliac disease on a large-scale map.

Adult↗
PubMed1995

Kinetics of anti-M2 antibodies after liver transplantation for primary biliary cirrhosis.

BACKGROUND/AIMS: Orthotopic liver transplantation is currently considered as the treatment of choice for primary biliary cirrhosis in the terminal stage and, as for other autoimmune liver disease, the risk of recurrence of the disease within the graft has been raised. There is, however, some discrepancy about the risk of recurrence based on pathological analysis. In addition, pathological recurrence of primary biliary cirrhosis within the graft is not always associated with a rise in the serological markers of the disease. In order to clarify this situation, we have monitored antimitochondrial antibodies before and after transplantation. METHODS: Antimitochondrial antibodies were detected by indirect immunofluorescence (variation in antibody titers) and the antimitochondrial antibodies-2 by western blotting (variation in the number of peptides recognized in 16 primary biliary cirrhosis patients followed for at least 4 years after transplantation. RESULTS: Antimitochondrial antibody titers had normalized 1 year after transplantation in seven patients, declined in seven others and remained unchanged in two. Over the 4 years of follow up, four patients demonstrated a subsequent increase in antimitochondrial antibody titers. Western blot analysis demonstrated the loss of one or more bands in seven patients during the first operative year after transplantation and in three other patients thereafter; in six patients the western blotting profile remained identical to that obtained before transplantation. The important changes generally occurred during the first year post-transplantation, without significant changes thereafter, except for three patients who demonstrated a secondary reappearance of the initially lost band. Disappearance of all bands was never observed. There was no concordance between the normalization of antimitochondrial antibody titers (indirect immunofluorescence) and the reduction in the number of peptides recognized (western blotting). Serum bilirubin and alkaline phosphatase levels had normalized by 1 year after transplantation, and remained normal thereafter. Routine liver biopsies performed on a yearly basis did not disclose any pattern suggestive of primary biliary cirrhosis recurrence. CONCLUSIONS: Antimitochondrial antibody titers decreased in primary biliary cirrhosis patients after liver transplantation, although antimitochondrial antibodies-2 never disappeared as assessed by western blotting. In the present study these features were not associated with biochemical or histological (correction of histoclogical) evidence of primary biliary cirrhosis recurrence.

Adult↗
PubMed1995

[Analysis of dot-blot technique for the detection of three autoantibodies (anti-Jo-1, anti-M2, anti-ribosome). Comparison with reference techniques].

A recently commercialized dot-blot (Cyto-Dot, BMD) offered a new method for the detection of three autoantibodies (Ab) anti-Jo-1, anti-M2, and anti-ribosomal protein although their only common point is the cytoplasmic localisation of their respective antigen. These Ab are detected by indirect immunofluorescence (IF) (anti-M2, anti-ribosomal protein), double immunodiffusion (ID) (anti-Jo-1) and western blotting (WB) (anti-M2). The aim of the study was to compare results obtained by the Cyto-Dot with those obtained by our reference technique. One hundred and seventy-seven sera were analysed, divided into four groups: group I (n = 15) with anti-Jo-1 Ab detected by ID, group II (n = 70) with anti-M2 Ab by WB, group III (n = 33) with anti-ribosomal protein Ab by IF (of which, 19 are precipitating by ID), group IV (control group, n = 59) with 31 sera of healthy individuals, six sera of patients with liver diseases resembling primary biliary cirrhosis and 22 with a particular serological profile. Cyto-Dot is very sensitive and specific for the detection of anti-Jo-1 Ab. Also, it represents a reliable method (sensitivity 0.99) for the screening of anti-M2 Ab and for the confirmation of an atypic immunofluorescence pattern. Equivalent to ID for the detection of anti-ribosomal protein Ab, the Cyto-Dot represents a good alternative technique. However, although this new diagnostic method represents a sensitive technique for the detection of the three auto-Ab, unfortunately, it can not be applied for large series.

Autoantibodies↗
PubMed1994

Comparisons of double immunodiffusion, ELISA, western blot and CAPE blot for the detection of anti-SSA antibody: study of anti-SSA prevalence in systemic lupus erythematosus.

The specificity and sensitivity of anti-SSA (Ro) antibody detection by double immunodiffusion, ELISA, western blot and a new method named CAPE blot were studied. Using 79 normal sera, 61 sera positive for anti-SSA (Ro) antibodies (double immunodiffusion), and 39 sera without anti-SSA (Ro) antibodies but containing anti-Sm, anti-RNP, anti-SSB (La), anti-Scl 70 and anti-PCNA antibodies, we compared ELISA, western blot and CAPE blot with the immunodiffusion assay. The sensitivities of the three methods were 100, 62 and 100%, respectively. Sera from 196 patients with systemic lupus erythematosus (SLE) were tested. The prevalence of anti-SSA (Ro) antibodies in this group was scored as 26% by double immunodiffusion, 47% by ELISA, 25% by western blot and 38% by CAPE blot.

Antibodies, Antinuclear↗
PubMed1994

Association of antimitochondrial antibodies type 5 and anti-beta 2 glycoprotein I antibodies in the antiphospholipid syndrome.

OBJECTIVE: To evaluate if antimitochondrial type 5 antibodies (AMA5) might be included among antiphospholipid syndrome (APS) markers. METHODS: In a retrospective study, blood variables of 48 patients with AMA5 were analyzed in relationship with clinical and biological markers of APS and systemic lupus erythematosus (SLE). RESULTS: We observed a high prevalence of false biological test for syphilis (95%), lupus anticoagulant (LAC) (71%), anticardiolipin antibodies (aCL) of IgG (71%) and IgM (75%) isotype, positive direct Coombs' test (54%), thrombocytopenia (52%), anti-B2 glycoprotein I antibodies (38%). Twenty-nine patients (61%) had at least one clinical manifestation of APS; 42% had recurrent arterial and/or venous deep thrombosis and 21% had recurrent fetal loss. But, for 2 patients, AMA5 were the sole detected immunological marker. Moreover, SLE was observed in 35% of the patients. These were different from 100 control patients with SLE with the respect to skin involvement and dsDNA antibodies which were less frequent (p < 0.01) and aCL, LAC, false biological test for syphilis (p < 0.001), positive direct Coombs' test and thrombocytopenia (p < 0.05) which were more frequent. CONCLUSION: Our data suggests (1) AMA5 is another marker of the APS (2) in patients with SLE, AMA5 seems to be a marker of a subset of SLE. This appears to justify the routine detection of these antibodies.

Adolescent↗
PubMed1994

[Comparison of indirect immunofluorescence on Crithidia luciliae of Farr test, and immunoenzymatic methods for the screening of anti-native DNA autoantibodies].

Anti-native DNA (ds DNA) antibodies were measured by the Farr assay, an indirect immunofluorescence on Crithidia luciliae (IIFCL) and a newly commercialised enzyme-linked immunosorbent assay (Elisa) in the sera of 270 patients: 73 negative controls, 67 patients with systemic lupus erythematosus (SLE), 73 with clinical symptoms of another connective tissue disease and 61 patients with liver diseases. The Farr assay remains a reliable method, IIFCL seems to be as specific but less sensitive and Elisa has a higher sensitivity but a lower specificity. Finally, 35 sera from the 270 patients were tested for anti-ds DNA antibodies using two other commercialised Elisa-related techniques. The results suggest little correlation between the three Elisa methods.

Animals↗
PubMed1994

[Prevalence and characteristics of anti-tissue antibodies in chronic hepatitis caused by hepatitis C virus].

OBJECTIVES: The prevalence and significance of antiorganelle antibodies in the serum of patients with chronic hepatitis C is a subject of controversy. We studied prospectively these characteristics in patients with chronic hepatitis C. METHODS AND RESULTS: Among 156 patients (age: 55 +/- 14 years; 83 females), 30 (19%) had significant titers of antiorganelle antibodies: anti-nuclear antibodies in 18, anti-smooth muscle antibodies in 8 (no anti-actin or anti-vimentine subtypes), anti-LKM1 in 2, type 2 anti-mitochondrial antibodies in 2 patients. Anti-organelle antibodies were not detected in 126 patients. Patients with anti-organelle antibodies were significantly older but no difference was found between the two groups for sex ratio, serum amino-transferases or gammaglobulins, histopathological liver activity or prevalence of lymphocytic sialadenitis. The presence of anti-organelle antibodies was not related to HLA phenotype, especially B8 DR3, or DR4. Response to alpha interferon, estimated by serum aminotransferase levels after six months of treatment, was the same in both groups. CONCLUSIONS: These results suggest that serum anti-organelle antibodies are prevalent in during chronic hepatitis C but do not indicate a distinct autoimmune mechanism. Furthermore, the typing of anti-smooth muscle antibodies might help distinguish chronic hepatitis C from type 1 autoimmune chronic hepatitis.

Adult↗
PubMed1993

[Development of an immunoenzyme assay technique of ELISA type for detecting anti-SSB antibodies. Comparative study of 2 kits].

The anti-SSB antibodies were measured using two enzyme immunoassays (ELISA). The difference between the both results from the preparation of the SSB antigenic extract. The first method, developed in our laboratory, uses a purified SSB antigen extracted from calf thymus, while the other uses an antigen cloned by genetic engineering. We have realized an analytic investigation about the repetability, the reproducibility and the detection limit of our ELISA method and we have refined its evaluation in using a clinic study carried out on 203 subjects (55 had a Sjögren syndrome, 47 had a systemic lupus erythematosus, 17 had a rheumatoid arthritis, 13 a progressive systemic sclerosis, 10 a polymyositis and 61 healthy subjects (blood donors)). These measures were worked out in order to compare them with the Ouchterlony method of reference. The results we have obtained are totally similar to the ELISA methods, with a global correlation factor of 0.96 in spite of the difference on the preparation of SSB antigenic extract. The enzyme immunoassay is a lot more sensitive than the Ouchterlony method since, for a Sjögren sample, we obtain a sensitivity of 0.69 while the sensitivity is only of 0.51 for the immunoprecipitation. In the lupus sample, the sensitivity is respectively of 0.42 and 0.25.

Antibodies, Antinuclear↗