Clinical features and risk factors in 126 patients with anti-MDA5 antibody positive dermatomyositis / 中华风湿病学杂志

ABSTRACT

Objective:To explore clinical factors of poor prognosis in patients with anti-melanoma differentiation-associated gene 5 andtibody positive dermatomyositis (MDA5-DM).Methods:One hundred and twenty-six enrolled adults with MDA5-DM were divided into the survival group and the deceased group according to the outcomes. Survival time, clinical manifestations, laboratory tests, pulmonary function tests, myositis antibodies and treatments were collected for statistical analysis. Serum concentrations of IL-15, HMGB1, and sCD163 were measured by ELISA in MDA5-DM patients and healthy controls. Mann-Whitney U nonparametric test and Student′s t-test were used to compare the continuous variables between the two groups, and χ2 or Fisher′s exact test were used for comparison of categorical variables. Cox regression analysis was used to assess the survival predictors in MDA5-DM patients. The cumulative survival rate was calculated by Kaplan-Meier curve analysis, and Log-rank tests were used to examine differences in survival curves. P<0.05 was considered statistically significant. Results:Cox multivariate regression analysis revealed that age > 57 years [ HR (95% CI)=3.05 (1.20, 7.80), P=0.020], RP-ILD [ HR (95% CI)=25.07 (5.42, 115.98), P<0.001], and levels of anti-Ro52 antibody [ HR (95% CI)=3.41 (1.36, 8.53), P=0.009] were important prognostic factors independent of multiple clinical parameters. The ELISA test results showed that the levels of serum IL-15[0.91 (0.66, 2.00)pg/ml vs. 0.51(0.39, 0.72)pg/ml, Z=-4.57, P<0.001] and HMGB1 [230.53(90.40, 394.31)ng/ml vs. 32.66 (17.82, 46.21)ng/ml, Z=-6.52, P<0.001] in MDA5-DM patients were significantly higher than those in healthy controls, but there were no significant differences in the level of serum IL-15 [1.21(0.63, 2.12)pg/ml vs. 0.91(0.68, 1.66)pg/ml, Z=-0.30, P=0.766], HMGB1[267.61(167.03, 444.23)ng/ml vs. 228.35(74.74, 344.32)ng/ml, Z=0.82, P=0.413], and sCD163 [112.70(93.45, 148.51)ng/ml vs. 132.72(96.79, 203.18)ng/ml, Z=-0.62, P=0.536] between the survival group and the deceased group. Conclusion:Older age, RP-ILD, and high levels of anti-Ro52 antibody significantly increase the risk of death in MDA5-DM patients. Intensive follow-up of patients with the above factors in the early stages may help to improve the prognosis.