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N Abuaf

Publications and source records attributed to N Abuaf.

At least 37 records · Page 2Linked to original sources
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

[Conclusions of the first French workshop of standardization of anticardiolipin antibody determination associated with autoimmune pathology].

Anticardiolipine antibodies are a marker of the antiphospholipid syndrome. They are detected by Elisa. Despite its simplicity, the results obtained by this assay are not always reproducible despite several worldwide standardizations and the distribution of calibration sera by EN Harris. On 4 December 1992, the First French Anticardiolipin Antibodies Standardization Workshop was held in Paris. Eight coded standards were sent to 33 laboratories in France, one in Switzerland and one in Luxembourg. Some of them used several assays. Agreement between qualitative results was good for samples with high and moderate level of antibodies. But the results expressed in IgG antiphospholipid units were scattered, the interlaboratory coefficient of variation for each of the eight standards was higher than 70%, though the within-run coefficient of variation had a median value of 10%. Assays using bovine serum for the blocking buffer and for the dilution buffer seemed to give more reproducible results than assays using purified bovine serum albumin (p < 0.001). For only nine assays out of 38 which expressed results quantitatively, was a linear regression observed between the dilutions of a sample and the results expressed in IgG antiphospholipid units. Absence of linearity is an obstacle which must be overcome if we wish to compare quantitative results obtained by different laboratories.

Antibodies, Anticardiolipin↗
PubMed1994

[Anti-mitochondrial antibodies type 5 are markers of antiphospholipid syndrome].

In order to investigate the clinical value of anti-mitochondrial antibodies type 5 (anti-M5), we carried out a retrospective study on 48 patients with these antibodies. Seventeen of these 48 patients (35%) satisfied at least 4 criteria of the revised American Rheumatism Association classification of SLE. Twenty-nine (61%) had at least one clinical manifestation of anti-phospholipid syndrome; thirteen had symptoms consistent with primary anti-phospholipid syndrome; five had isolated recurrent thrombosis; five had Evans' syndrome; four had auto-immune haemolytic anaemia; two had immunologic thrombocytopenia. Two of the 48 patients had no clinical manifestations, but only anti-M5 and a false laboratory test for syphilis (FBTS). Our data confirm that patients with anti-M5 have a high prevalence of: 1) thrombosis (42% had three or more deep thromboses) and fetal loss (21%); 2) auto-immune cytopenia with idiopathic thrombocytopenic purpura (29%) and auto-immune haemolytic anaemia (54%); 3) laboratory markers of anti-phospholipid syndrome (lupus anticoagulant (71%), FBTS (95%) and anticardiolipin antibodies (aCL) (71%). For 32 patients with anti-M5, anti-beta 2 glycoprotein I antibodies were also tested; 12 (38%) were positive, all of whom had IgG aCL, ie none had anti-beta 2GPI antibodies without aCL. There was no association between the presence of anti-beta 2GPI antibodies and recurrent thrombosis among patients with anti-M5. All these findings suggest that anti-M5 is another marker of the antiphospholipid syndrome. Even though the prevalence of anti-M5 is low, especially in SLE, it was the only marker of the anti-phospholipid syndrome in two patients; this appears to justify routine screening for these antibodies.

Adolescent↗
PubMed1994

[Why are some allergens enzymes?].

In the last ten years, progress in the field of allergy research has led to the purification of some of the major allergens and to a better knowledge of their physico-chemical properties. A number of studies have shown that some allergens have enzymatic activities. Molecular biology has provided the means to clone and sequence genes encoding these allergens and to produce recombinant allergens in yeast and bacteria. Epitope mapping of natural and synthetic allergens, using polyclonal or monoclonal antibodies and cell-stimulation tests, has also contributed greatly to the understanding of their immunogenicity and allergenicity. Analysis of these new data allow us to explain why some allergens are enzymes.

Acari↗
PubMed1994

[Prevalence and significance of non-specific anti-organelle antibodies of the liver in chronic viral hepatitis C].

OBJECTIVES: The aim of this study was to evaluate the prevalence and the clinical signification of non organ specific autoantibodies in chronic hepatitis C. METHODS: We studied retrospectively 158 consecutive patients (97 with chronic hepatitis C, 24 with chronic hepatitis B, 67 with alcoholic cirrhosis) and 100 blood-donors. RESULTS: The prevalence of anti-nuclear and anti-smooth muscle antibodies was lower in blood donors than in patients (P < 0.001), but was comparable among the 3 groups of patients. The anti-liver-kidney microsome type 1 antibodies were detected only in patients with chronic hepatitis C (6%). The serum gammaglobulin level was significantly higher in patients with hepatitis C and anti-nuclear antibody titers > or = 1/50. The anti-smooth muscle antibodies detected in patients with hepatitis C had no anti-actin specificity. The response to interferon was not related to the detection of non organ specific autoantibodies before treatment. CONCLUSION: Anti-nuclear or anti-smooth muscle antibodies are not characteristic of hepatitis C virus infection.

Adult↗
PubMed1994

[Autoantibodies in the diagnosis of vascular diseases].

Vascular abnormalities are frequent in connective tissue disease. In this kind of patients a lot of autoantibodies are observed. To screen them a strategy must be selected according to the connective tissue disease that is suspected. When the diagnosis is unknown the tests must screen a great number of autoantibodies and this is the case for indirect immunofluorescence assays, at the opposite when the diagnosis is known antibodies specific for the disease should be screened. Some antibodies are specific for a disease this is the case for antibodies directed against double stranded DNA, centromere, extractable nuclear antigens Sm, RNP, Scl-70, Pm-Scl, Jo1, neutrophil cytoplasmic antigen proteinase 3, and beta 2-glycoprotein I the cofactor of anti-cardiolipin antibodies. Anti-SS-A(Ro) antibodies are very frequent in autoimmune diseases and they are not specific for anyone of them. Some autoantibodies are frequent in autoimmune and also in non autoimmune diseases and this is the case for antibodies directed against phospholipids, single stranded DNA, histones, rheumatoid factor. The detection of antibodies depends on the assays used for screening, that is why results should mention the assay used for their detection. The standardization of the detection of the autoantibodies especially when quantitative results are requested, is not yet performed enough. So to obtain reproducible results when monitoring a patient the screening must be done by the same assay in the same laboratory.

Antibody Specificity↗
PubMed1993

Flow cytometric evaluation of human basophils.

The expression of CD45 and IgE cell surface antigens on human leucocytes was studied by flow cytometry. More than 80% of sorted cells that expressed low CD45 (CD45dim) and high IgE (IgEbright) antigen site density were identified as basophils. Immunomagnetic depletion of the CD45dim-IgEbright cell subset by a biotin-coupled anti-IgE antibody and streptavidin-coated magnetic beads was greater than 90%, and more than 80% of cells binding significant numbers of beads exhibited the morphological characteristics of basophils. Interestingly, when the cell staining was performed in the presence of calcium and magnesium, we observed a significant increase of CD45 and an equivalent decrease of IgE cell surface expression, as well as an IgE concentration dependent diminution of the number of CD45dim-IgEbright cells.

Antibodies, Anti-Idiotypic↗
PubMed1993

Non-organ specific autoantibodies associated with chronic C virus hepatitis.

Recently antibodies to hepatitis C virus were detected in sera of chronic active hepatitis patients, with anti-smooth muscle autoantibodies or with anti-liver/kidney microsomal type 1 autoantibodies. As the latter were used to differentiate autoimmune chronic active hepatitis from chronic non-A, non-B virus hepatitis, it was mainly important to discover if autoantibodies were associated with chronic hepatitis C virus infection. The sera of 272 chronic hepatitis C patients were screened by indirect immunofluorescence for non-organ specific autoantibodies. Antinuclear antibodies and anti-smooth muscle autoantibodies were more frequent in chronic hepatitis C patients than in blood donors (n = 100). Anti-liver/kidney microsomal type 1 autoantibodies were not detected in the sera of the blood donors, in the 74 hepatitis B patients or in the 30 alcoholic hepatitis or cirrhotic patients' sera tested as controls. They were detected in 14 chronic hepatitis C patients. These antibodies were compared in immunodiffusion to anti-liver/kidney microsomal type 1 autoantibodies sera obtained from type-2 autoimmune chronic active hepatitis patients and an identity reaction was observed. Chronic hepatitis C patients without or with anti-liver/kidney microsomal type 1 autoantibodies, did not differ in age, sex ratio, transaminases and gammaglobulin level, risk factors for hepatitis C virus infection, association with other autoimmune diseases. These patients differed significantly from type-2 autoimmune chronic active hepatitis patients. We conclude that: (i) in some chronic hepatitis C patients the pattern and the titer of autoantibodies may create confusion with an autoimmune chronic active hepatitis; (ii) There is no serological evidence for a hepatitis C virus infection in true type-2 autoimmune chronic active hepatitis.

Adolescent↗
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↗
PubMed1992

Liver/kidney microsome antibody type 1 and hepatitis C virus infection.

Recent studies have shown that hepatitis C virus antibodies are present in a large proportion of patients with autoimmune hepatitis type 2. We have studied 83 patients with liver/kidney microsome antibody-positive type 1 hepatitis. Hepatitis C virus antibodies were sought in every case by second-generation tests (hepatitis C virus enzyme-linked immunosorbent assay and recombinant immunoblot assay). Hepatitis C virus RNA sequences were sought in 22 patients (12 with recombinant immunoblot assay-positive results and 10 with recombinant immunoblot assay-negative results) by means of polymerase chain reaction and by use of primers located in the 5' noncoding region. Sixty-four patients (77%) had positive results for hepatitis C virus antibodies in the enzyme-linked immunosorbent assay test, and 41 (49.3%) were confirmed by recombinant immunoblot assay. Hepatitis C virus RNA sequences were found in all the recombinant immunoblot assay-positive patients but in none of the 10 who were recombinant immunoblot assay-negative. The recombinant immunoblot assay-negative patients were younger than those who were positive (13 +/- 11 vs. 50 +/- 11 years) and had higher gamma-globulin levels and liver/kidney microsome antibody-positive type 1 titers (61% had a titer of 1:1,000 or more, vs. only 17% of the recombinant immunoblot assay-positive patients).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Characterization of the liver cytosol antigen type 1 reacting with autoantibodies in chronic active hepatitis.

An autoantibody to liver cytosol was previously described in childhood autoimmune chronic active hepatitis type 2. The antigen, liver cytosol antigen type 1, was for the first time partially purified using gel filtration and ion exchange chromatography, and it was characterized using immunodiffusion, immunoblot and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the immunoprecipitate. Immunoblot detected a unique antigenic peptide at 62 kD from human cytosol and at 58 kD from rat cytosol. The same peptides were also detected when immunoprecipitates of liver cytosol antigen type 1 and autoantibodies to liver cytosol antigen were submitted to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. A polymeric structure, probably a tetramer, is suggested for native liver cytosol antigen type 1 because in gel filtration chromatography liver cytosol antigen type 1 was eluted as a protein of a molecular weight between 240 and 290 kD when human liver cytosol was fractionated and between 220 and 270 kD from rat liver cytosol. Liver cytosol antigen type 1 is probably poor in carbohydrates because it was not stained by periodic acid-Schiff stain. The autoantibodies to liver cytosol were frequently found in association with antiliver kidney microsomal autoantibodies type 1, which are directed against the cytochrome P-450 of the IID6 subfamily. Antiliver kidney microsomal autoantibodies type 1 but not antiliver cytosol autoantibodies were found in association with antibodies to hepatitis C virus. Autoantibodies to liver cytosol antigen type 1 seem to be a more specific marker for autoimmune hepatitis type 2 than antiliver kidney microsomal antibodies type 1 autoantibodies.

Animals↗
PubMed1992

Long-term follow-up study of 164 patients with definite systemic sclerosis: classification considerations.

To evaluate the usefulness of recently proposed schemes of classification for systemic sclerosis an extensive cross-sectional study of a series of 164 consecutive patients with long-term systemic sclerosis was undertaken. There were 47 cases of proximal sclerosis, 93 of distal sclerosis and 24 of complete CREST syndrome. The study included clinical, visceral, immunological and follow-up data. In addition, a quantitative clinical score was calculated for each patient, thus providing indications for prognosis. Data were expressed according to three conventional systems of classification: The ARA system, the diffuse versus limited systemic sclerosis system and the early cutaneous involvement system. The most reliable indications of severe outcome were: proximal sclerosis, trunk skin involvement, presence of anti Scl 70 autoantibody, pulmonary and/or heart involvement and age. Diagnosis and prognosis were not generated by the same items. Prognosis indicators proved more accurate for groups than for individuals. Mortality was 1 death per 149 patient X years of follow-up from diagnosis. We conclude that the ARA criteria for classification should be recognized as a standard, but patients with complete CREST syndrome should be included in the distal group. Other systems of classification, principally 2-way versus 3-way criteria, allow different subsets of patients that correlate with prognosis and the severity of the disease, and could be used for therapeutic purposes.

Adolescent↗
PubMed1992

Platelet size and volume distribution measured by automated platelet analyzer.

Thirty migraine without aura patients between attacks, 10 other during a migraine without aura attack and 30 normal subjects without headache were studied for platelet size and volume distribution using a new quantitative automated hematology analyzer (Coulter STKS). Platelet histograms, platelet counts and mean platelet volume were not significantly different in the three populations.

Adult↗
PubMed1991

Anti-liver-kidney microsome antibody-positive autoimmune hepatitis associated with alopecia.

A 14-year-old girl presented with anti-liver-kidney microsome autoimmune hepatitis preceded by alopecia 3 years earlier. Both pathologies were greatly improved by immunosuppressive therapy. Alopecia is a newly reported extrahepatic manifestation of type 2 autoimmune hepatitis. Its appearance could alert the clinician to an increased risk of autoimmune hepatitis in children.

Adolescent↗
PubMed1991

Mapping of epitopes on U1 snRNP polypeptide A with synthetic peptides and autoimmune sera.

The ability of synthetic peptides encompassing almost the entire sequence of snRNP U1A polypeptide to be recognized in ELISA by sera of autoimmune patients was investigated. Sera from 18 patients with mixed connective tissue disease (MCTD), 145 with systemic lupus erythematosus (SLE) and 120 with other rheumatic autoimmune diseases were tested with 13 overlapping peptides. Among them, peptide 257-282 and, to a lower extent, peptide 1-11 were recognized by MCTD, SLE and Sjögren's syndrome sera. In contrast, peptide 35-58 was recognized by 94% of MCTD and only 19% of SLE sera. It did not react with any of the other patient sera. The ELISA results were compared with the pattern of reactivity observed in immunoblotting. The results indicate that peptide 35-58 probably contains a major epitope recognized by MCTD autoantibodies. It is noteworthy that in snRNP particles, this region of U1A interacts with RNA and presents only limited homology with the corresponding sequence 32-50 of U2B''.

Amino Acid Sequence↗
PubMed1991

The significance of circulating antiethinyl-estradiol antibodies (AEEA) in the occurrence of thrombosis in women while taking the pill.

The aim of the study was to investigate the hypothesis that oral contraceptives (OC) lead to antiethinyl-estradiol antibody (AEEA) synthesis which might in turn be responsible for the thrombo-embolic complications observed in women users. The trial included 428 women divided into a) 204 healthy female volunteers as the control group (CONT), b) 139 women who had suffered thrombo-embolic accidents (THR), c) 85 women suffering from recurrent fetal loss (RFL). In each of these three categories, 50% were pill users (OC+) and 50% were not (OC-). Specific immune markers of systemic autoimmunity and anticardiolipin antibodies were looked for, as they are thought to be present in increased amounts in thrombosis or recurrent fetal loss. The AEEA prevalence differed significantly (p less than 0.05) between the CONT OC+ (32%) and the CONT OC- (13%) women. It also differed (p less than 10(-5)) between the RFL OC+ (60%) and the RFL OC- (12%) women. It did not differ between THR OC+ (36%) and THR OC- (39%) women. Within the OC+ women, the difference between the THR and the CONT groups was not found to be significant, whereas it was found to differ significantly between the RFL and the CONT groups (odds-ratio RFL/CONT estimated at 3.20, confidence interval 1.53, 6.69). Within the OC-women, the AEEA prevalence was found to differ significantly between the THR (39%) and the CONT (13%) groups (odds-ratio THR/CONT estimated at 4.40, confidence interval 2.07, 9.38%) but not between the RFL and the CONT groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗