Acute respiratory distress syndrome (ARDS) occurs in Clinically Amyopathic Dermatomyisitis(CADM) combined with Rapidly Progressive Interstitial Lung Disease(RPILD) within 1-3 months, which leads to death of patients and is difficult to treat. Even if high doses of glucocorticoids are ineffective, there is no recommended treatment for such patients, which is a huge medical challenge.Lymphopenia is an independent risk factor for death in CADM-RPILD, but the cause of lymphopenia is unclear.In this study, the level of lymphocyte subsets in peripheral blood was detected by flow cytometer, in order to further clarify the pathogenesis of the disease, to facilitate clinical guidance of treatment, and to improve the survival rate of patients.In addition, studies have shown that INF-α levels are significantly increased in CADM patients combined with RPILD and are a poor prognostic factor for CADM-RPILD, suggesting that the interferon system plays a role in the pathogenesis of CADM and can be used as an evaluation index of the severity of CADM-RPILD.In this study, the levels of relevant cytokines including INF and IL-2, IL-17, IL-18, IL-6 were detected simultaneously, and the relationship between disease activity and lymphocyte subsets was analyzed, and the changes of lymphocyte subsets after Tofacitinib treatment were determined in order to facilitate clinical guidance of treatment.

Inclusion Criteria:

1. Age≥18 years old,≤80years old,no gender limit;
2. CADM of diagnosis according to Sontheimer diagnostic criteria;
3. combined with Rapidly Progressive Interstitial Lung Disease

Exclusion Criteria:

1. Age<18years old，>80years old;
2. potential malignant tumor

Patient with Clinically Amyopathic Dermatomyisitis combined with Rapidly Progressive Interstitial Lung Disease