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Biomedical subjects

N Abuaf

Publications and source records attributed to N Abuaf.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Evaluation of a radioimmunologic technique for the detection of anti-native DNA antibodies].

The anti-native DNA antibodies were measured by a radioimmunoassay (RIA) type Farr assay in the sera from 648 patients: 108 with active or inactive systemic lupus erythematosus (SLE), 181 with clinical symptoms of another connective tissue disease, 171 with liver diseases, 29 with different pathology and 159 normal sera were obtained from a blood bank. The anti-DNA kit has been calibrated against the first international units/ml. This assay has proved to be sensitive and specific, and appears to be reliable for the diagnosis and follow-up of SLE patients. The authors propose a new reference cut-off level higher than producer's one.

Antibodies, Antinuclear↗
PubMed1990

Sera with high levels of anti-smooth muscle and anti-mitochondrial antibodies frequently bind to cytoskeleton proteins.

Using ELISA methods, 54 sera from chronic active hepatitis (CAH) patients displaying high levels of anti-smooth muscle antibodies (SMA) and 18 sera from primary biliary cirrhosis (PBC) patients with high levels of anti-M2 antibodies were examined for the presence of high antibody levels against actin, tubulin, myosin, tropomyosin, troponin, vimentin and desmin. Our results showed that: (i) in CAH with high SMA activity, increased antibody levels were found in 51.9% of sera for actin, 31.5% for myosin, 35.2% for tubulin, 34.0% for tropomyosin, 11.3% for troponin, 22.6% for vimentin and 43.4% for desmin, compared with natural antibody levels in 21 normal sera; (ii) Similar high levels of these antibodies were found in the case of PBC; (iii) in most cases, sera simultaneously bound to several antigens of the panel; and (iv) approximately 26% of the CAH sera were found to be negative with the seven antigens examined while 22% were reacted with a cytoskeleton protein (CP) other than actin. These results indicate that current opinion associating SMA with anti-actin activity in CAH is confirmed for only 50% of cases and that although a good correlation between SMA and anti-CP antibodies can be obtained, there is still a significant percentage of SMA for which the putative antigen recognized needs to be determined.

Animals↗
PubMed1990

Detection of autoantibodies to Sm antigen in systemic lupus erythematosus by immunodiffusion, ELISA and immunoblotting: variability of incidence related to assays and ethnic origin of patients.

Autoantibodies to small nuclear ribonucleoproteins (snRNP) were studied using the techniques of immunodiffusion, ELISA, and immunoblotting in the sera of 150 patients with systemic lupus erythematosus (SLE), and of 29 patients with mixed connective tissue disease; 900 control patients and 100 normal blood donors were examined simultaneously. The incidence of anti-Sm antibodies in French SLE patients was low compared with the occurrence observed in similar studies in USA (even when highly sensitive assays were used) but was of the same magnitude as European results. Frequency of anti-Sm antibodies in SLE patients varied moderately when detected by immunodiffusion (12%), or by immunoblotting (17%), however, it seems that the ethnic and/or genetic background of patients induces more significant differences. SLE patients from the French West Indies had anti-Sm antibodies in 39% of cases when detected by immunodiffusion and in 50% when immunoblotting was used. In these patients the incidence of the antibodies was five times more frequent than that of mainland French patients. Immunization against snRNP does not seem to be a common feature of all SLE patients.

Antibody Specificity↗
PubMed1990

[Anti-Scl-70 antibodies in systemic scleroderma].

We looked for anti-Scl-70 and anti-centromere antibodies in 109 patients (26 men and 83 women). Mean age was 43 +/- 15 years. Forty patients had systemic sclerosis according to ARA criteria. The extension of cutaneous involvement was defined by using Barnett and Coventry criteria: 12 patients were type I (sclerodactyly), 20 type II (acrosclerosis) and 8 type III (diffuse scleroderma). Among the 12 patients with type I, there were 8 cases of CREST syndrome defined as follows: presence of sclerodactyly, Raynaud's phenomenon and 2 of the 3 following criteria: oesophageal dysmotility, calcinosis, telangiectasia. Other organ involvement was recorded. Control patients had idiopathic Raynaud's phenomenon (n = 22), other connective tissue diseases (n = 20), and miscellaneous diseases (n = 28). Ninety-nine patients were prospectively included in this study. Patients' sera were stored at -20 degrees C. Ten previously stored sera obtained from patients with systemic sclerosis were also analyzed. Immunological tests were performed simultaneously and with no information on the diagnosis. When antinuclear antibodies were detected by indirect immunofluorescence, double immunodiffusion and immunoblotting were performed. Anti-Scl-70 antibodies were detected in systemic sclerosis only: 1 of 12 type I, 11 of 20 type II and 4 of 8 type III. One serum negative by immunodiffusion was positive using immunoblotting. We found that the specificity of anti-Scl-70 antibodies for systemic sclerosis was 100 p. 100 and their sensitivity 40 p. 100. There was a correlation between the presence of anti-Scl-70 antibodies and the presence of antinuclear antibodies (p less than 0.05) and the extent of cutaneous involvement (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Contribution of immunoenzymatic technics to the assay of anti-native DNA antibodies in the biological diagnosis of lupus erythematosus disseminatus].

Anti native DNA antibodies (anti nDNA Ab), which are a highly specific feature of systemic lupus erythematosus (SLE) were measured by 3 methods: an enzyme linked immunosorbent assay (ELISA), an indirect immunofluorescence test on Crithidia luciliae (IFCL) and the Farr assay (reference test). 114 sera from patients with SLE or another connective tissue disease or without autoimmune rheumatic disease were tested. This study showed that ELISA seemed to be a more sensitive and specific test than IFCL (classical test). ELISA was also as sensitive as the Farr assay. ELISA should replace IFCL for the diagnosis and the follow up of patients with SLE. In other connective tissue diseases, ELISA might give more positive results. Thus these had to be confirmed, especially in the case of low antibodies levels, by using another method (e.g., the Farr assay).

Antibodies, Antinuclear↗
PubMed1990

Serological arguments for classifying Raynaud's phenomenon as idiopathic.

Twenty-five patients with idiopathic Raynaud's phenomenon were followed prospectively for a mean period of 48 months. Clinical and laboratory assessments were performed on admission and on followup. The sera were analyzed for the presence of autoantibodies (antinuclear, antiskeleton and antiorganelle antibodies). Sixteen patients were antinuclear antibody positive and 2 anticentromere antibody positive. Eight patients produced antivimentin, 5 antimitochondrial, 4 anti-Golgi complex, and 3 anticentriol antibodies. Eleven patients produced antidesmosome antibodies. Only one patient (anti-RNP and antidesmosome antibody positive) developed a systemic disease (mixed connective tissue disease) during followup. The initial screening of sera may help to classify Raynaud's phenomenon as idiopathic more accurately.

Adolescent↗
PubMed1989

[Anti-Scl-70 and anti-centromere autoantibodies. Biological markers of 2 forms of systemic scleroderma].

The diagnostic and prognostic value of anti-Scl-70 autoantibodies in systemic scleroderma and other connective tissue diseases was investigated. A clinical and immunological study consisting of a search for anti-Scl-70 autoantibodies by immunodiffusion and immunoblot and a search for anti-centromere autoantibodies and antinuclear factors by indirect immunofluorescence was conducted in 57 cases of systemic scleroderma, 45 cases of CREST syndrome, 41 patients with suspected systemic scleroderma but who did not respond to the American rheumatism association (ARA) criteria, 35 cases of systemic lupus erythematosus, 8 cases of polymyositis, 40 cases of Raynaud's phenomenon and 48 controls. Anti-Scl-70 autoantibodies were found by immunodiffusion in 40 and by immunoblot in 45 cases of scleroderma with lesions proximal to the metacarpo-phalangeal joint (a major ARA criterion) and in 3 patients with suspected scleroderma but only one minor criterion: sclerodactyly. In systemic scleroderma with proximal lesions, the anti-Scl-70 autoantibody has a sensitivity of 0.85 and a specificity of 0.99. Anti-centromere autoantibodies were present in 39 cases of complete or incomplete CREST syndrome, 3 cases of Raynaud's phenomenon probably evolving towards a connective tissue disease and 1 case of systemic scleroderma with proximal lesions. The anti-Scl-70 and anti-centromere autoantibodies seem unable to coexist in the same patient and appear to be markers of two forms of scleroderma with different courses and prognoses. The Scl-70 antigen, which is the target of the anti-Scl-70 antibody, has been identified as topoisomerase 1, and a functional abnormality of this enzyme might contribute to some of the chromosomal abnormalities described in scleroderma.

Autoantibodies↗
PubMed1989

Characteristics of clometacin-induced hepatitis with special reference to the presence of anti-actin cable antibodies.

The clinical, biochemical, histopathological and immunological features of 30 cases of clometacin-induced hepatitis are described. The age range of the patients was 32-84 years with a notable female predominance of 29:1. The hepatitis was highly cytolytic with high values of transaminases but with little or no cholestasis. Gammaglobulins were higher than 18 g/l in 73% of the cases. 25 liver biopsies were performed and showed acute hepatitis with a predominant centrilobular necrosis in 17; chronic aggressive hepatitis was noted in 8 cases but 1 showed concomitant cirrhotic changes. Anti-tissue antibodies were looked for in all cases. Anti-smooth muscle antibodies of anti-actin cable type (titre 1/80 to 1/2, 560) were detected in 19 cases, anti-nucleus antibodies in 16 cases which were associated to the former in 14 cases. The above findings show that clometacin produces a hepatitis syndrome quite akin to autoimmune chronic active hepatitis (lupoid hepatitis) and to the hepatopathy induced by oxyphenisatin.

Actins↗
PubMed1989

[Idiopathic portal hypertension associated with connective tissue disease similar to systemic lupus erythematosus].

A case of idiopathic portal hypertension associated with connective disease resembling systemic lupus erythematosus is described. The patient was a 50-year-old woman with splenomegaly, ascites, esophageal varices, and pancytopenia, but without extrahepatic portal obstruction or cirrhosis of the liver. Electron microscopy of the liver showed perisinusoidal fibrosis. High titers of autoantibodies against proliferating cell nuclear antigen (PCNA) were found in the sera as well as in ascites; anti-DNA antibodies appeared after anti-PCNA antibodies and remained thereafter at a moderate titer. The possibility of an immunological process in the pathogenesis of idiopathic portal hypertension is discussed.

Antibodies, Antinuclear↗
PubMed1987

Autoimmunity in 28 patients after allogeneic bone marrow transplantation: comparison with Sjögren syndrome and scleroderma.

The occurrence of autoantibodies in 28 long-term survivors of allogeneic bone marrow transplantation (BMT) (21 with chronic graft-versus-host disease) was compared with 48 cases of idiopathic Sjögren syndrome and 82 cases of scleroderma. Antinuclear, anti-smooth muscle, and anti-mitochondria antibodies occurred respectively in 80%, 82% and 14% of the post BMT cases. Anti-native DNA, anti-soluble nuclear antigen and anticentromere antibodies were not found. Antiepidermal antibodies were present in 14% of the cases but their pathological role is unclear. Although the clinical manifestations of chronic graft-versus-host disease are similar to Sjögren syndrome and scleroderma the autoantibody profile is significantly different.

Adult↗
PubMed1987

Anti-mitochondrial type 5 antibodies and anti-cardiolipin antibodies in systemic lupus erythematosus and auto-immune diseases.

Twenty sera from patients with systemic lupus erythematosus (SLE) and high titre of IgG anti-cardiolipin antibodies (ACA) were studied in order to evaluate the prevalence of anti-mitochondrial type 5 antibodies (AMA 5). None of these sera were found to be AMA 5 positive but five of 18 were positive for VDRL. Twenty sera from patients with AMA 5 were studied in order to evaluate the prevalence of ACA: only six of 20 were positive for ACA. In contrast to this finding, 15 of the 20 sera positive for AMA 5 were also positive for VDRL (P less than 0.001). The six sera positive for ACA and AMA 5 were absorbed with cardiolipin micelles. This absorption eliminated the ACA activity but not the AMA 5 activity. Despite the clinical similarities between the two groups of patients with AMA 5 or ACA, these data suggest that patients with AMA 5 and patients with ACA belong to two different subsets of SLE or SLE-like syndromes and that AMA 5 antigen is different from cardiolipin.

Autoantibodies↗
PubMed1987

Detection of anti-mitochondrial antibodies by ELISA and Western-blot techniques and identification by one and two-dimensional gel electrophoresis of M2 target antigens.

Seven hundred and eleven sera were simultaneously studied by immunofluorescence (IF), complement fixation test (CFT) and ELISA for the detection of anti-mitochondrial antibodies (AMA). One hundred and nineteen of these sera were also studied by Western-blot techniques, while some of them were examined by two-dimensional gel electrophoresis so as to identify the polypeptides recognized by M2 antibodies. The results indicated that: (1) ELISA is a more sensitive technique for detecting type M2 AMA (27 scored positive in 27 primary biliary cirrhosis (PBC), as compared to 21/27 by IF and 16/27 by CFT). (2) Although ELISA appeared to be a promising screening method, some false positive results were observed that necessitated a double confirmation of positive sera by another technique. (3) Western-blot experiments with rat mitochondrial purified preparation indicated that sera from AMA type 2 could recognize eight different polypeptides and that most of them identified 63-60, 48, 44, and 35-33 kD polypeptides, whereas the 54 and 27 kD were less frequently recognized. A trypsin treatment of antigens confirmed the enzyme sensitivity of most of these antigens. These results suggested some heterogeneity among M2 AMA, though this series of PBC was not large enough to relate the heterogeneous pattern noticed in Western-blot to the clinical and histological patterns observed in PBC.

Autoantibodies↗
PubMed1987

Comparing HEp-2 cell line with rat liver in routine screening test for antinuclear and antinucleolar autoantibodies in autoimmune diseases.

The comparative study of the human tumor cell line HEp-2 and rat liver for the detection of antinuclear and antinucleolar autoantibodies by the indirect immunofluorescence technic in routine screening test demonstrate that, taking titer and staining pattern into account, both substrates are able to separate autoimmune disease (systemic lupus erythematosus, rheumatoid arthritis, scleroderma and primary biliary cirrhosis) patients from healthy subjects. The minimal screening test must include sera diluted 1:20 and 1:80. The capability of the HEp-2 substrate to reveal and to discriminate different speckled nuclear and nucleolar patterns explain its greater performance, notably in detecting anticentromere antibodies highly specific for the CREST syndrome and a speckled nuclear antibody frequently associated with primary biliary cirrhosis, allowing an earlier diagnosis of autoimmune diseases presenting these patterns.

Adult↗
PubMed1986

Blocking IgG antibodies after rush immunotherapy with mites.

The synthesis of blocking antibodies has been demonstrated in ten patients undergoing rush immunotherapy (R-IT) with mite extracts: basophil degranulation performed on washed cells (Allergolam technique) did not differ significantly before and 10.8 (+/- 6.8) months after R-IT. Preincubation of allergen (100, 25, 10, and 5 micrograms/mL) with individual serum collected before R-IT did not decrease degranulation, but degranulation was significantly decreased when the allergen was incubated 30 minutes at 37 degrees C with individual serum collected after R-IT or with the IgG-fraction of a pool of sera collected in 22 treated patients. A linear correlation between the mean of degranulation and the log allergen concentration was observed in the two latter groups. The antigen neutralizing capacity of the IgG-fraction was studied on basophils of 11 "allergic donors." Antigen neutralizing capacity clearly increased with time of incubation with the allergen (15, 30, and 60 min), but was also significant without preincubation, eg, for 10 and 5 micrograms/mL allergen concentrations. These results indicate that the improvement of asthma usually noticed 2 months after R-IT is probably due, essentially, to blocking antibodies, since the sensitivity of the basophils is not modified significantly.

Adolescent↗
PubMed1984

A new anti-liver-kidney microsome antibody (anti-LKM2) in tienilic acid-induced hepatitis.

The sera of 131 patients with anti-liver-kidney microsome antibodies (anti-LKM) detected between 1973 and 1979 in two different laboratories were re-examined. (1) Eighty-six anti-LKM corresponded to the description given by Rizzetto, Swana & Doniach (1973), with a pattern of fluorescence predominating on the 3rd portion of the proximal tubules (P3). This group comprised 45 cases of idiopathic chronic hepatitis or idiopathic cirrhosis and one case of halothane-induced hepatitis. (2) Forty-five anti-LKM gave a different pattern on male mouse liver and male rat kidney: (a) fluorescence was greater on centrolobular than on periportal hepatocytes; (b) the first and second portions of proximal tubules (P1 and P2) predominated over P3; (c) P1 fluorescence was equally intense as P2 and (d) P3 cells were heterogeneous with one cell out of 20 more positive than the rest. Absorption tests confirmed that the corresponding antigen was also present in the liver microsomal fraction. A retrospective clinical study discovered tienilic acid-induced hepatitis in all cases. We suggest naming this new antibody 'anti-LKM2'.

Adolescent↗
PubMed1984

[Comparison of human tumor cells (Hep 2) and rat liver for the detection of antinuclear antibodies by indirect immunofluorescence].

Indirect immunofluorescent detection of anti-nuclear antibodies was conducted on sections of rat liver and on smears of human Hep 2 tumour cells in the serum of 1017 patients. Overall, the Hep 2 cells gave titres superior by 1 or 2 dilutions. Taking into account this difference, a good agreement was observed between the 2 cellular reagents in 83 per cent of the sera tested. The divergences, which affect almost one half of the positive sera, are largely due to the presence of anti-centromere antibodies, anti-nuclear antibodies giving a patchy "M3" appearance to the Hep 2 cells and, most importantly, anti-nucleolar antibodies. Such differences demonstrate that there are major qualitative or quantitative antigenic differences between the nuclei of rat hepatocytes and those of Hep 2 cells. Although technically rat liver and Hep 2 cells were found to be fairly easy to use and interpret, only a large comparative study of human pathology will be able to determine which is the better reagent for the routine detection of anti-nuclear antibodies.

Animals↗