Comprehensive assessment of myositis-specific autoantibodies in polymyositis/dermatomyositis-associated interstitial lung disease.

Myositis-specific autoantibodies (MSAs) are associated with clinical phenotypes in polymyositis/dermatomyositis (PM/DM). No study has investigated the clinical features based on comprehensive MSA assessment in PM/DM-associated interstitial lung disease (ILD). We aimed to determine the practical significance of MSAs in PM/DM-ILD. Sixty consecutive PM/DM-ILD patients were retrospectively analysed. Serum MSAs were comprehensively measured using immunoprecipitation assay. Clinical features and prognosis were compared among MSA subgroups. Twenty-six (43.3%) PM/DM-ILD patients were anti-aminoacyl tRNA-synthetase antibody-positive (anti-ARS-positive), 15 (25.0%) were anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5-positive), 3 (5%) were anti-signal recognition particle antibody-positive, 1 (1.7%) was anti-transcriptional intermediary factor 1-gamma antibody-positive, and 15 (25%) were MSA-negative. There were significant differences in clinical features, including ILD form, serum ferritin and surfactant protein-D levels at ILD diagnosis, and high-resolution CT pattern among the anti-ARS-positive, anti-MDA5-positive and MSA-negative groups. The anti-MDA5-positive group showed the lowest 90-day survival rate (66.7%, anti-MDA5-positive; 100%, anti-ARS-positive; 100%, MSA-negative; P < 0.01). The anti-ARS-positive group had the highest 5-year survival rate (96%, anti-ARS-positive; 66.7%, anti-MDA5-positive; 68.3%, MSA-negative, P = 0.02). Univariate analysis revealed that anti-ARS antibody was associated with better prognosis (HR = 0.45; 95% CI, 0.18-0.89; P = 0.02), whereas anti-MDA5 antibody was associated with poorer prognosis (HR = 1.90; 95% CI, 1.02-3.39; P = 0.04). The comprehensive MSA assessment demonstrated that anti-ARS and anti-MDA5 antibodies were two major MSAs, and the clinical features differed depending on MSA status in PM/DM-ILD. Assessment of anti-ARS and anti-MDA5 antibodies is practically useful for predicting clinical course and prognosis in PM/DM-ILD patients.

Hozumi H ，Fujisawa T ，Nakashima R ，Johkoh T ，Sumikawa H ，Murakami A ，Enomoto N ，Inui N ，Nakamura Y ，Hosono Y ，Imura Y ，Mimori T ，Suda T ... -  《-》

Association of anti-aminoacyl-transfer RNA synthetase antibody and anti-melanoma differentiation-associated gene 5 antibody with the therapeutic response of polymyositis/dermatomyositis-associated interstitial lung disease.

We attempted to clarify whether the presence of anti-aminoacyl-transfer RNA synthetase antibody (anti-ARS Ab) or anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) is associated with the therapeutic response of polymyositis/dermatomyositis-associated interstitial lung disease (PM/DM-ILD). We retrospectively investigated 22 patients with PM/DM-ILD (10 positive for anti-ARS Ab and nine positive for anti-MDA5 Ab) for whom antibody analysis of conserved serum was possible. We assessed mortality in the first three months as the therapeutic response in the acute phase and compared changes in clinical data for up to one year considered as the chronic phase. We classified the clinical changes over the year into three groups: Improvement (increased % vital capacity [%VC] or diffusing capacity of the lung for carbon monoxide [%DLCO]≥10 or 15%), deterioration (decreased %VC or %DLCO≥10 or 15%), and no change (remainder of the changes). The extent of abnormality demonstrated by high-resolution computed tomography (HRCT) was scored. Positivity for anti-MDA5 Ab, but not for anti-ARS Ab, was associated with mortality in the first 3 months. Evaluation of the therapeutic response in the first year showed that positivity for the anti-ARS Ab, but not for the anti-MDA5 Ab, was associated with an improvement in %DLCO and a decline in the serum KL-6 levels. Positivity for the anti-ARS Ab or negativity for anti-MDA5 Ab was associated with a greater decrease in bronchial dilatation as seen by HRCT. Anti-ARS and anti-MDA5 Abs are associated with the therapeutic response of PM/DM-ILD.

Yoshida N ，Okamoto M ，Kaieda S ，Fujimoto K ，Ebata T ，Tajiri M ，Nakamura M ，Tominaga M ，Wakasugi D ，Kawayama T ，Kuwana M ，Mimori T ，Ida H ，Hoshino T ... -  《-》

Clinical characteristics of dermatomyosits/polymyositis associated interstitial lung disease according to the autoantibody.

Kishaba T ，McGill R ，Nei Y ，Ibuki S ，Momose M ，Nishiyama K ，Nagano H ，Yamashiro S ... -  《-》

The long-term outcome of interstitial lung disease with anti-aminoacyl-tRNA synthetase antibodies.

Anti-aminoacyl transfer RNA synthetase antibodies (anti-ARS) are a group of myositis-specific autoantibodies that are detected in the sera of patients with polymyositis and dermatomyositis (PM/DM) and also in those of patients with idiopathic interstitial pneumonias without any connective tissue disease (CTD), including PM/DM. Although we reported the clinical characteristics of interstitial lung disease with anti-ARS antibodies (ARS-ILD) with and without PM/DM, the long-term prognosis of ARS-ILD remains undetermined. As our previous studies revealed that ARS-ILD without PM/DM was similar to CTD-associated ILD, and that ARS-ILD with PM/DM was radiologically suggestive of a nonspecific interstitial pneumonia (NSIP) pathological pattern, we hypothesized that the prognosis of ARS-ILD might be distinct from that of idiopathic pulmonary fibrosis (IPF) without anti-ARS. To elucidate the long-term outcome of ARS-ILD with and without PM/DM and compare it to that of IPF. A two-center retrospective study was conducted. The study population comprised 36 patients with ARS-ILD (8 with PM, 12 with DM, and 16 without myositis throughout the course), 100 patients with IPF without anti-ARS, and 7 patients with NSIP without anti-ARS. The presence of anti-ARS was determined by RNA immunoprecipitation using the sera obtained at the time of diagnosis before specific treatment. During the observational period (median 49 months; range, 1-114 months), 7 patients with ARS-ILD (19%; 3 with PM, 1 with DM, and 3 without PM/DM) and 51 patients with IPF (51%) died. Patients with ARS-ILD had better overall survival than those with IPF (log-rank test, P < 0.001) and similar survival compared to those with NSIP (log-rank test, P = 0.59). The prognosis for patients with ARS-ILD was similar between those with and without myositis (log-rank test, P = 0.91). At the median follow-up time of 76.5 months, 14 of the 36 patients with ARS-ILD had deteriorated. Both a decline in forced vital capacity or an initiation of long-term oxygen therapy during the course (odds ratio [OR], 5.34) and acute exacerbation (OR, 28.4) significantly increased the mortality risk. The long-term outcome of ARS-ILD was significantly better than that of IPF regardless of the presence or absence of myositis.

Tanizawa K ，Handa T ，Nakashima R ，Kubo T ，Hosono Y ，Watanabe K ，Aihara K ，Ikezoe K ，Sokai A ，Nakatsuka Y ，Taguchi Y ，Hatta K ，Noma S ，Kobashi Y ，Yoshizawa A ，Oga T ，Hirai T ，Chin K ，Nagai S ，Izumi T ，Mimori T ，Mishima M ... -  《-》

Comparison of cytokine profiles between anti-ARS antibody-positive interstitial lung diseases and those with anti-MDA-5 antibodies.

Asakawa K ，Yoshizawa K ，Aoki A ，Kimura Y ，Tanaka T ，Ohashi K ，Hayashi M ，Kikuchi T ，Sato S ，Takada T ... -  《-》