目的 Infection occurrence, especially its risky factors and its indicators during immunosuppressive agents use for patients with interstitial lung diseases (ILD) secondary to dermatomyositis (DM) are not well described.The aim of this study was to establish indicators and risky factors of infection during intensive treatment for DM patients.方法 The clinical records of 76 patients with DM-ILD (135 episodes) were retrospectively reviewed.And infection-related data was extracted, including symptom of fever, microbiological study, inflammatory markers CRP and D-dimer, CD4+ T cell counts, steroids and immunosuppressive agents use during hospitalization, and in-hospital mortality.结果 According to patients with positive microbiological results or not, patients were divided into two groups.Patients with DMILD who had positive microbiological findings were easier to manifest as fever and had higher degree of fever than that of negative populations.Accordingly, laboratory data indicated that positive patients had elevated serum inflammatory indicator CRP, and decreased CD3+CD4+ T cells counts, when compared to negative ones.For exploring the infection-related factors, longer intensive steroids use more than 14 days and higher FK506 serum concentrations were related to the microorganism occurrence.Meanwhile, short-term investigation of in-hospital mortality related to infection had no statistical difference when compared the both groups.结论 The current study indicates that DM-ILD patients with positive microbiological results have higher CRP level and lower CD4+ T cell counts, and its appearance is associated with longer steroids use and higher serum concentration of tacrolimus.