Search

Resume Objectif Dans la sclerodermie systemique (ScS) et les myopathies inflammatoires idiopathiques (MII), les auto-anticorps sont utilises dans la pratique quotidienne comme biomarqueurs des phenotypes cliniques. Cette etude vise a estimer la prevalence des anticorps specifiques des myosites (ASM) et des anticorps associes aux myosites (AAM) en utilisant deux tests immunoblots differents dans une cohorte de patients atteints de ScS bien caracterises, puis a etudier leurs associations cliniques. Methodes Dans cette etude transversale, les serums de 300 patients ont ete testes de facon consecutive, avec realisation simultanee des tests immunoblots « myosites » Euroimmun® et D-tek®. Resultats La prevalence des ASM/AAM, ASM et AAM etait respectivement de 17,0 %, 8,0 % et 9,7 %. En combinant les resultats des deux tests, des anticorps anti-PM/Scl 100 etaient presents chez 5,0 % (intervalle de confiance a 95 % : 2,8 ; 8,1) ; anti-PM/Scl 75 et anti-TIF1γ chez 3,7 % (1,8 ; 6,5) ; anti-Ku chez 3,0 % (1,4 ; 5,6) ; anti-MDA5 chez 1,3 % (0,4 ; 3,4) ; anti-Mi-2 β, anti-NXP2, anti-PL-7 et anti-SRP chez 0,7 % (0,08 ; 2,4) ; anti-EJ et anti-PL-12 chez 0,3 % (0,01 ; 1,8) des patients. Aucune reactivite anti-SAE1, Jo-1 ou OJ n’a ete observee. Les anticorps anti-PM/Scl 75 etaient associes a la pneumopathie interstitielle (80 % contre 42 %) et la myosite (27 % contre 3 %) ; les anticorps anti-Ku etaient associes avec la myosite (33 % contre 3 %). Conclusion Dans cette etude transversale portant sur 300 patients atteints de ScS, la prevalence des ASM/AAM, des ASM et des AAM, testes a partir de deux immunoblots differents, etait respectivement de 17,0 %, 8,0 % et 9,7 %. La positivite des AAM etait associee a la pneumopathie interstitielle et a la myosite, mais cette etude n’a pas mis en evidence d’association clinique avec les ASM.

Objective In systemic sclerosis (SSc) and idiopathic inflammatory myopathies (IIM), auto-antibodies are used in daily practice as potent biomarkers of clinical phenotypes. This study aimed at estimating the prevalence of myositis-specific (MSA) and myositis-associated (MAA) auto-antibodies in a well-characterised SSc patients cohort using two different immunoblot assays, and studying their clinical associations. Methods In this cross-sectional study, the sera of 300 consecutive patients were tested at the same time with myositis antibodies Euroimmun® and D-tek® immunoblot assays. Results Prevalence of MSA/MAA, MSA and MAA were 17.0%, 8.0% and 9.7%, respectively. When combining results of both tests, anti-PM/Scl 100 were found in 5.0% (95% confidence interval 2.8; 8.1); anti-PM/Scl 75 and anti-TIF1γ in 3.7% (1.8; 6.5); anti-Ku 3.0% (1.4; 5.6); anti-MDA5 in 1.3% (0.4; 3.4); anti-Mi-2 β, anti-NXP2, anti-PL-7 and anti-SRP in 0.7% (0.08; 2.4); anti-EJ and anti-PL-12 in 0.3% (0.01; 1.8) of patients. No reactivity against SAE1, Jo-1 or OJ was observed. Anti-PM/Scl 75 antibodies were associated with interstitial lung disease (80% vs. 42%) and myositis (27% vs. 3%); anti-Ku antibodies were associated with myositis (33% vs. 3%). Conclusion In this cross-sectional study of 300 SSc patients, the prevalence of MSA/MAA, MSA and MAA using immunoblot assays were 17.0%, 8.0% and 9.7%, respectively. MAA positivity was associated with ILD and myositis, but this study did not highlight any clinical associations with MSA positivity.