Objectives. To evaluate in various soups of patients with chronic joint disease the sensitivity and specificity of nti-Sa antibody, recently described in sera from adults with rheumatoid arthritis (RA); and to determine the prognostic significance of anti-Sa in initial sera from patients with long standing RA with or without severe joint destruction.Methods. Serum samples from 489 patients were included. Of these, 154 were collected from patients with RA attending 2 rheumatology units. Controls were 335 patients with a variety of inflammatory joint diseases other than RA. IgG anti-Sa was detected using an immunoblotting method with purified Sa antigen from human placenta extracts. All patients were tested for the following antibodies: rheumatoid factor (RF), anti-keratin antibody (AKA), antiperinuclear factor (APF), and anti-RA 33. HLA class II DRB alleles were also determined.Results. Anti-Sa was detected in 39.8% of RA sera overall, 46.7% of sera from the long standing Re group, and 23.5% of sera from the recent onset RA group (p < 0.01). In patients with long standing RA, statistically significant associations were found between the presence of anti-Sa and the following variables: RF (p < 0.0001), AKA (p < 0.0001), APF (p < 0.00001), and HLA DRB1*04 or 01 (p < 0.01). In contrast, no association was found with anti-RA33. Anti-Sa was positive in 11 adult controls (7.8%) and in 26 pediatric patients with juvenile chronic arthritis (22%). The specificity of anti-Sa for RA was 92.1% in adults with well characterized rheumatic diseases and 85.9% in adults and children together. Among patients with long standing RA, those with destructive disease were more likely to test positive for anti-Sa (66.6%) than those with nondestructive disease (22.2%) (p < 0.0001). Comparisons with other serologic markers for RA demonstrated that anti-Sa was sensitive (68.4%) and was also the test with the highest specificity (79%), positive predictive value (75%), and negative predictive value (71%) for discriminating between patients who do and those that do not develop late severe radiographic damage.Conclusion. Immunoblot-detected IgC anti-Sa is a sensitive serologic marker for RA patients with severe radiographic damage.

Objectifs. Cette etude s'est attachee a determiner par Western blot le profil des proteines 68 kDa, A, B/B', C et D des complexes Ul-RNP reconnues par des serums de patients souffrant de connectivites mixtes, de lupus systemiques et de diverses autres connectivites comportant des anticorps anti-RNP depistes par precipitation en gelose. Materiel et methodes. Un dosage ELISA des IgG anti-68 kDa U1-RNP a ete effectue pour comparer les taux d'anticorps obtenus dans les differentes situations cliniques: connectivites mixtes du Sharp (n=20), lupus (n=14) et autres connectivites (n=5). Une etude longitudinale a compare le profil clinique des patients, l'evolutivite de leur maladie et soit le spectre des anticorps (68 kDa, A, B/B', C et D) deceles, soit le taux des anti-68 kDa U1-RNP. Resultats. Les resultats obtenus montrent que les connectivites mixtes et les lupus systemiques ont une frequence egale d'anti-68 kDa U1-RNP et des taux identiques d'IgG anti-68 kDa U1-RNP. Les connectivites mixtes ont de facon significative plus souvent des anti-A et des anti-C-RNP que les lupus systemiques (p<0,03 et 0,04). La taille de la serie ne permet pas de trouver une association significative entre un signe clinique de connectivite mixte (Raynaud, myosite, doigts boudines,...) et un auto-anticorps particulier. Le suivi longitudinal (moyenne de suivi: 7 ans, extremes: 1-25 ans) montre l'existence de variations dans le profil des anticorps anti-proteines du Ul-RNP, ainsi que dans le taux des anti-68 kDa, sans toutefois trouver de relation avec l'evolutivite clinique de la maladie, qu'il s'agisse de connectivite mixte ou de lupus systemique. Conclusion. L'existence d'IgG anti-68 kDa ne permet pas de differencier les differentes connectivites avec anti-RNP. II n'est pas utile de suivre la maladie sur le taux d'IgG anti-68 kDa Ul-RNP. L'existence en Western blot d'anti-A et/ou C -Ul RNP est associee aux connectivites mixtes de Sharp.

OBJECTIVES To determine whether the anti-68 kDaU1snRNP antibody is associated with mixed connective tissue disease and not with SLE; to evaluate correlations between anti-U1snRNP titers and disease activity; and to look for associations between anti-U1snRNP specificities and specific clinical features. PATIENTS AND METHODS 40 patients with a positive double diffusion test for anti-68 kDa U1snRNP were studied, including 21 with mixed connective tissue disease, 14 with systemic lupus erythematosus and five with other connective tissue diseases. IgGs to 68 kDa U1snRNP were assayed using an ELISA. Clinical features, disease activity and antibody test findings were evaluated longitudinally in nine patients. RESULTS Both proportions of patients with anti-68 kDa U1snRNP and titers of IgG to 68 kDa U1snRNP were similar in the mixed connective tissue disease and systemic lupus erythematosus groups. Patients with mixed connective tissue disease were significantly more likely to have anti-A U1snRNP or anti-C U1snRNP than those with systemic lupus erythematosus (P < 0.03 and P < 0.04, respectively). No significant correlations were found between any of the features of mixed connective tissue disease (e.g., Raynaud's phenomenon, myositis, or sausage digits) and a specific anti-U1snRNP antibody. During follow-up (mean, seven years; range, 1-25 years), changes occurred in the anti-U1snRNP profile and in the anti-68 kDa U1snRNP titer. These changes were not correlated with disease activity. CONCLUSIONS IgGs to 68 kDa U1snRNP are not associated with a specific pattern of anti-RNP-positive connective tissue disease. No useful information can be gained by monitoring anti-68 kDa U1snRNP IgG titers over time. A Western blot profile including anti-A U1snRNP or anti-C U1snRNP indicates a high likelihood of U1snRNP-associated mixed connective tissue syndrome (MCTD).

Anticentromere antibodies identified by indirect immunofluorescence are a valuable aid to the diagnosis and prognosis of patients with systemic sclerosis since they are associated in 50% to 80% of cases with limited cutaneous systemic sclerosis, a pattern usually associated with a good prognosis. We studied clinical presentations in rheumatology patients with anticentromere antibodies by indirect immunofluoresence and by ELISA and/or Western blot, but without scleroderma or Raynaud's phenomenon. Eight of 34 (23.5%) rheumatology clinic patients with centromere antibodies met these criteria, seven women and one man, with a median symptom duration of six years (range 1-20 years). Four had Sjögren's syndrome, one had isolated xerostomia, one systemic lupus erythematosus, one seronegative symmetric polyarthritis and one primary biliary cirrhosis with arthralgia. The mean anticentromere antibody titer in these eight patients was similar to that in the patients who had at least Raynaud's phenomenon. Given the low incidence of scleroderma, these data illustrate the poor predictive value of anticentromere antibodies for the diagnosis of scleroderma in rheumatology clinic patients.

Les anticorps anticentromere deceles par immunofluorescence indirecte (IFI) constituent un marqueur de diagnostic et de pronostic tres utile devant une sclerodermie systemique, puisqu'ils sont associes dans 50 a 80 % des cas a une sclerodermie systemique a forme cutanee, limitee, presumee benigne. Ce travail s'est interesse a la presentation clinique des malades rhumatologiques ayant des anticentromere en IFI confirmes en ELISA et/ou en Western blot, mais ne repondant pas au diagnostic de sclerodermie et n'ayant pas de phenomene de Raynaud: ainsi 8 observations ont ete retenues parmi 34 malades ayant des anticorps anticentromere et consultant en rhumatologie (23,5 %). Il s'agit de 7 femmes et 1 homme dont le recul evolutif moyen des manifestations est de 6 ans (extremes = 1-20 ans): 4 ont un syndrome de Gougerot-Sjogren, 1 a une xerostomie isolee. Les trois derniers ont: un lupus systemique 1 fois, une polyarthrite symetrique seronegative 1 fois et une cirrhose biliaire primitive avec arthralgies 1 fois. Le titre moyen des anticorps anticentromere est identique, chez ces 8 malades, a celui observe dans les autres observations qui comportaient au moins un phenomene de Raynaud. Compte tenu de l'incidence faible des sclerodermies, ces resultats attirent l'attention sur la valeur predictive positive mediocre des anticorps anticentromere pour le diagnostic de sclerodermie dans une population consultant en rhumatologie.

The goal of this prospective longitudinal study was to determine the serological profile of early rheumatoid arthritis (RA), and to test whether antikeratin antibody (AKA), antiperinuclear factor (APF), anti-RA33 antibody and antinuclear antibodies (ANA) had an additional diagnostic value when prescribed after rheumatoid factor (RF)-detecting methods. Sixty-nine patients with early polyarthritis suggestive of RA, seen between 1991 and 1993, were included. Five autoantibodies (i.e. RF, AKA, APF, RA33, ANA) were looked for at regular intervals. After 24 months follow-up, patients were classified as having RA (n = 49), unclassified polyarthritis (UP; n = 15) or other rheumatic diseases. Among patients with early RA, the sensitivity of these markers was 40.8% for RF, 36.7% for AKA, 28.6% for APF and 28.6% for anti-RA33. Among RF-negative RA patients, 51.7% were positive for AKA, APF, anti-RA33 antibodies and/or ANA. Positivity of the three recent markers usually persisted throughout follow-up, whereas RF was lost by 58% of patients with early, RF-positive, treated RA. Using multivariate analysis, only latex, RF test and AKA or APF had an independent and statistically significant diagnostic value for early RA. Our data suggest that RF and AKA (or APF) should be concomitantly determined for diagnosis in patients with suspected early RA.

We determined the occurrence of antineutrophil cytoplasmic antibodies (ANCAs) and their specificities in 77 rheumatoid arthritis (RA) patients and compared them with 25 patients with psoriatic arthritis (Pso), 19 with drug-induced lupus erythematosus (DI-LE) and 11 with systemic lupus erythematosus (SLE). Thirty-two percent of RA patients had positive indirect immunofluorescence (IIF) stains (P or atypical ANCA). Twenty-nine per cent of patients with rheumatoid vasculitis (RAV), 48% with long-standing RA (LSRA) and 20% with early RA (Ely RA) had positive ANCAs compared with 4% of Pso patients, 47% of DI-LE patients and 45% of SLE patients. Western blotting (with polymorphonuclear cell extracts or alpha-granules) and alpha-granule enzyme-linked immunosorbent assay (ELISA) yielded variable results and proved unhelpful for characterizing the specificities of ANCAs. ELISAs based on commercial purified lactoferrin (LF), myeloperoxidase (MPO), human elastase (HLE) and cathepsin G (CG) showed that anti-HLE antibody was the most prevalent (14%) antibody in RA, followed by anti-MPO antibody and anti-LF antibody (10% each). Statistical analysis of antibody prevalence by clinical presentation showed that LSRA patients were more likely to have anti-HLE antibody and that DI-LE patients were more likely to have anti-CG antibody compared with the other patient groups. In lupus patients serial ELISA titration of ANCAs (LF and MPO) was found to be reliable for predicting the outcome. The overall incidence of ANCAs in RA patients was 33% by IIF.

Les cellules endotheliales vasculaires sont la cible potentielle d'auto-anticorps (AAEV) vis-a-vis d'antigenes membranaires exprimes constitutivement, induits ou fixes a leur surface. Pour tester cette hypothese, nous avons utilise un test ELISA avec comme substrats deux types de cellules endotheliales humaines : soit des cellules de veine de cordon ombilical humain (CEVH), soit une lignee de cellules hybrides EAhy-926 obtenues par fusion de CEVH avec une lignee tumorale de carcinome bronchique A549. L'etude fonctionnelle comparee des cellules CEVH et de EAhy-926 a montre que les cellules EAHy-926 produisaient peu de facteur VIII Willebrand et de facteur tissulaire, ne comportaient pas de corps de Weibel Palade en microscopie electronique et exprimaient de l'ICAM-1 et de la selectine E a hauteur de 15 p. cent du taux exprime par le CEVH apres stimulation par le lipopolysaccharide bacterien (LPS) ainsi qu'a l'etat basal. Cependant la determination des AAEV IgG sur les deux types de cellules a montre une bonne concordance des taux obtenus par les deux methodes, tant pour les serums de vascularite rhumatoide que pour ceux des malades ayant un syndrome des anticorps anti-phospholipides. Ces anticorps ne sont pas cytotoxiques vis-a-vis des cellules CEVH ou EAhy-926. Ils ne sont pas specifiques de l'endothelium puisqu'il est possible d'adsorber en moyenne 40 p. cent de leur activite par une incubation prealable des serums sur la lignee epitheliale A549. Une etude transversale portant sur 565 serums a montre la presence d'AAEV vis-a-vis de la lignee EAhy-926 de type IgG et IgM, principalement au cours des polydermatomyosites (IgG 58 p. cent, IgM 22 p. cent), des sclerodermies systemiques (IgG 48 p. cent, IgM 18 p. cent), des syndromes de Sjogren primitifs (IgG 44 p. cent, IgM 12 p. cent) et des vascularites systemiques secondaires et primitives (IgG 38 p. cent, IgM 18 p. cent), dont la granulomatose de Wegener (GW). Une etude longitudinale au cours de la GW a montre l'interet de la determination des AAEV au cours du suivi de la maladie comme index evolutif.

Vascular endothelial cells may be a target for autoantibodies (AECAs) against membrane antigens that are constitutively expressed, induced or bound to their surface. To test this hypothesis, we used an enzyme-linked immunosorbent assay (ELISA) with two types of human endothelial cells as the substrate, i.e., human umbilical cord vein endothelial cells (HUVECs) or the hybrid cell line EAhy-926 obtained by fusion of HUVECs with the bronchial carcinoma cell line A549. A comparative functional study of these two cell types demonstrated that EAhy-926 cells produced only small amounts of VIII von Willebrand factor and tissular factor, did not contain Weibel Palade bodies visible under the electron microscope, and expressed ICAM-1 and selectin E in levels of no more than 15% of those expressed by human umbilical cord vein endothelial cells both after stimulation by bacterial lipopolysaccharide and under basal conditions. However, the two assay methods yielded similar IgG AECA titers when used on sera from patients with rheumatoid vasculitis or antiphospholipid syndrome. These antibodies did not exhibit cytotoxicity for cord vein or EAhy-926 cells. They were not specific for endothelium, since their activity decreased by a mean of 40% after incubation of sera with the epithelial cell line A549. A cross-sectional study of 565 sera demonstrated that anti-vascular IgG and IgM AECAs reactive with EAhy-926 cells occurred mainly in patients with dermatomyositis (IgG, 58%; IgM, 22%), systemic scleroderma (IgG, 48%; IgM, 18%), primary Sjögren's syndrome (IgG, 44%; IgM, 12%) and secondary and primary systemic vasculitides (IgG, 38%; IgM, 18%) including Wegener's granulomatosis. A longitudinal study in patients with Wegener's granulomatosis showed that AECAS were predictive of disease activity.

Besides rheumatoid factor (RF), antikeratin antibodies (AKA) and antiperinuclear factor (APN), anti-RA 33 antibody has been described as a highly specific antinuclear antibody for rheumatoid arthritis (RA). In this study RA 33 antibodies were detected using Western blotting with HeLa cell nuclear extract in a group of 94 RA patients and 259 controls. Anti-RA 33 was present in 35% of 94 RA patients, with a similar frequency in RF positive (32%) and RF-negative (45%) RA patients. RA-33 antibody was also present in 60% of a group of 30 patients with anti-U1 RNP positive mixed connective tissue disease. The specificity of anti-RA 33 for RA was 84.6%. Anti-RA 33 antibody was already present in sera from 23.5% of 18 patients with RA of less than one year's duration. Anti-RA 33 antibody was the only positive immunological marker in 3/20 cases of seronegative adult RA. No correlations were found between anti-RA 33 antibody and AKA or APF. Patients with erosive RA and patients whose ESR was > or = 50 mm after 1 hour were more likely to be anti-RA 33 positive (47.6% vs 24.4% and 42.8% vs 29.4%). These results suggest that anti-RA 33 antibody, in the absence of anti-U1-RNP antibodies, can be added to the list of the helpful serological markers for rheumatoid arthritis.