Objective: To summarize the characteristics of different subtypes of antisynthetase syndrome (ASS) and ASS complicated with rapidly progressive interstitial lung diseases (RP-ILD). Methods: Clinical data of 78 patients with ASS were retrospectively analyzed

clinical manifestations and laboratory test results of different subtypes of ASS were compared

and clinical characteristics

treatment and outcome of ASS combined with RP-ILD were emphatically analyzed. Results: A total of 78 ASS patients were divided into five groups: the anti-Jo-1 antibody positive group was 33 patients (42.3%)

the anti-PL-7 positive group was 15 patients (19.2%)

the anti-PL-12 positive group was 16 patients (20.5%)

the anti-EJ positive group was 11 patients (14.1%) and anti-OJ positive group was 3 patients (3.8%). The incidence of ASS complicated with interstitial lung diseases (ILD) was 84.6%. Among ILD

RP-ILD was found in seven patients (9%)

of which two were positive for anti-PL-12 antibody (12.5%)

four were positive for anti-JO-1 antibody (12.1%)

and one was positive for anti-PL-7 antibody (6.6%). Six of the seven RP-ILD patients had non-specific interstitial pneumonia (NSIP) and one had usual interstitial pneumonia (UIP). Six patients with NSIP in RP-ILD type were treated by methylprednisolone combined with cyclophosphamide

five of whom were relieved after treatment and one was lost to follow-up. One patient with UIP of RP-ILD type was passed away. Conclusion: Among the clinical manifestations of ASS

the incidence of ASS with ILD is the highest. The incidence of RP-ILD is the highest in the anti-PL-12 positive group. NSIP main in the RP-ILD can be treated with glucocorticoid combined with immunosuppressive therapy.