Clinical characteristics of 272 cases with anti-MDA5 antibody positive dermatomyositis / 中华风湿病学杂志

ABSTRACT

Objective:To analyze the clinical features of MDA5 antibody positive dermatomyositis (MDA5-DM) and to provide evidence for early diagnosis and treatment.Methods:From March 2019 to June 2021, 272 patients with anti-MDA5-DM from the Nanjing Medical University myositis-associated interstitial lung disease cohort were enrolled, with 76 patients with anti-synthetase syndrome (ASS) as the control group. The clinical characteristics and the occurrence of interstitial lung disease were analyzed. T-test was used for normally distributed and variance-homogeneous independent samples, Mann-Whitney U test for non-normally distributed data, and chi-square test or Fisher′s exact test for dichotomous variables. Results:Among the 272 anti-MDA5-DM patients, 88.6% (241/272) developed interstitial lung disease (ILD), and 33.8% (92/272) developed rapidly progressive ILD (RP-ILD). The six-month all-cause mortality rate of anti-MDA5-DM patients was 16.9% (46/272), and it was as high as 47.8% (44/92) for those with RP-ILD. Compared with ASS patients, anti-MDA5-DM patients had a significantly higher proportion of males, arthritis, Gottron's sign, heliotrope rash, V-sign, periungual erythema, and skin ulcers ( P<0.05). The levels of ALT, AST, and ferritin were significantly increased ( P<0.05). Compared with non-RP-ILD patients, RP-ILD patients had a significantly higher proportion of males [35.9%(33/92) vs. 23.3%(42/180), χ2=4.79, P=0.029], higher levels of LDH [387 (276, 547) U/L vs. 310 (245, 400) U/L, Z=-3.67, P<0.001], ESR [45.5 (29.25, 63.25) mm/1 h vs. 31.2 (20, 51) mm/1 h, Z=-3.71, P<0.001], CRP [10.9 (4.1, 25.2) mg/L vs. 4.54 (2.58, 9.08) mg/L, Z=-4.97, P<0.001], ferritin [1 340 (650, 2 000) ng/ml vs. 556 (203, 1 186) ng/ml, Z=-4.40, P<0.001], and a higher proportion of anti-Ro52 antibody and anti-MDA5 antibody co-positivity [87.0%(80/92) vs. 52.2%(94/180), χ2=31.87, P<0.001]. Conclusion:Anti-MDA5-DM patients are prone to develop RP-ILD and have poor prognosis.