Extended myositis-specific and -associated antibodies profile in systemic sclerosis: A cross-sectional study.

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. 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. 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%). 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.

Leurs A ，Dubucquoi S ，Machuron F ，Balden M ，Renaud F ，Rogeau S ，Lopez B ，Lambert M ，Morell-Dubois S ，Maillard H ，Béhal H ，Hachulla E ，Launay D ，Sobanski V ... -  《-》

Evaluating the diagnostic utility of new line immunoassays for myositis antibodies in clinical practice: a retrospective study.

Montagnese F ，Babačić H ，Eichhorn P ，Schoser B ... -  《-》

Prevalence of anti-synthetase antibodies among systemic sclerosis patients.

we aimed to estimate the prevalence of Amino acyl-transfer ribonucleic acid synthetase antibodies (Anti-ARS); myositis specific antibodies, among patients with systemic sclerosis (SSc), to evaluate the clinical associations of anti-ARS antibodies in SSc patients and to identify risk factors for development of interstitial lung disease (ILD) in SSc. A prospective study of 71 systemic sclerosis patients in our rheumatology clinic in Israel. Sera were tested for myositis antibodies. Data on patients clinical and serological manifestations and treatment were collected and compared according to anti-ARS antibodies and ILD. Prevalence of anti-ARS antibodies was 6% (4/71) with anti PL-7, anti- OJ and Jo-1 positivity. Anti Ro-52 was found in 27%, anti-PM/Scl 75, anti-PM/Scl 100 and anti-SRP in 6%, anti-Ku in 3%, anti-Mi-2 beta and anti-Mi-2 alfa in 4%, anti- NXP2 and anti-TIF1gamma in 1%. ILD complication was observed in 42% of patients and was associated with anti RNAP-III, anti Scl-70 and Anti-ARS antibodies. In multiple logistic regression, anti Scl-70 was associated with 6-fold higher risk for ILD. Anti-ARS antibodies were observed in 6% of SSc patients. All of them had ILD. Due to the low prevalence of anti-ARS, this study could not describe clinical associations of anti-ARS antibodies in SSc patients.

Garra W ，Levy Y 《-》

[Myositis specific and myositis associated autoantibodies in idiopathic inflammatory myopathies: a serologic study of 46 patients].

Ghirardello A ，Zampieri S ，Iaccarino L ，Tarricone E ，Tonello M ，Bendo R ，Rondinone R ，Cozzi F ，Doria A ... -  《-》

Frequencies and clinical associations of myositis-related antibodies in The Netherlands: A one-year survey of all Dutch patients.

Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of connective tissue diseases, collectively known as myositis. Diagnosis of IIM is challenging while timely recognition of an IIM is of utter importance considering treatment options and otherwise irreversible (severe) long-term clinical complications. With the EULAR/ACR classification criteria (2017) considerable advancement has been made in the diagnostic workup of IIM. While these criteria take into account clinical parameters as well as presence of one autoantibody, anti-Jo-1, several autoantibodies are associated with IIM and are currently evaluated to be incorporated into classification criteria. As individual antibodies occur at low frequency, the development of line blots allowing multiplex antibody analysis has improved laboratory diagnostics for IIM. The Euroline myositis line-blot assay (Euroimmun) allows screening and semi-quantitative measurement for 15 autoantibodies, i.e. myositis specific antibodies (MSA) to SRP, EJ, OJ, Mi-2α, Mi-2β, TIF1-γ, MDA5, NXP2, SAE1, PL-12, PL-7, Jo-1 and myositis associated antibodies (MAA) to Ku, PM/Scl-75 and PM/Scl-100. To evaluate the clinical significance of detection and levels of these autoantibodies in the Netherlands, a retrospective analysis of all Dutch requests for extended myositis screening within a 1 year period was performed. A total of 187 IIM patients and 632 non-IIM patients were included. We conclude that frequencies of MSA and MAA observed in IIM patients in a routine diagnostic setting are comparable to cohort-based studies. Weak positive antibody levels show less diagnostic accuracy compared to positive antibody levels, except for anti-NXP2. Known associations between antibodies and skin involvement (anti-MDA5, anti-TIF1-γ), lung involvement (anti-Jo-1), and malignancy (anti-TIF1-γ) were confirmed in our IIM study population. The availability of multiplex antibody analyses will facilitate inclusion of additional autoantibodies in clinical myositis guidelines and help to accelerate diagnosing IMM with rare but specific antibodies.

Platteel ACM ，Wevers BA ，Lim J ，Bakker JA ，Bontkes HJ ，Curvers J ，Damoiseaux J ，Heron M ，de Kort G ，Limper M ，van Lochem EG ，Mulder AHL ，Saris CGJ ，van der Valk H ，van der Kooi AJ ，van Leeuwen EMM ，Veltkamp M ，Schreurs MWJ ，Meek B ，Hamann D ... -  《-》