Clinical management of antisynthetase syndrome: Series of 46 cases

Objective To summarize the characteristics, treatment and prognosis of different subtypes of antisynthetase syndrome(ASS). Methods Clinical data about 46 patients with antisynthetase syndrome admitted to our center from January 2010 to July 2018 were collected, and the clinical manifestations, laboratory test results, treatment, outcomes and prognosis of different subtypes of antisynthetase syndrome were investigated and the characteristics of ASS combined with interstitial lung disease(ILD) were emphasized. Results Of the 46 cases, there were 35 women and 11 men. The age of onset was 24-86 years, and the average age was 53 years. The course of disease was 0.5-720 months(Mean, 36 months). Anti-Jo-1 antibody was found to be positive in 35(76.1%)cases, anti-EJ antibody in 6(13.0%) cases, anti-PL-7 antibody in 3(6.5%) cases, anti-PL-12 antibody in 1(2.2%) case and anti-OJ antibody in 1(2.2%) case. ILD simultaneously occurred in 45 patients(97.8%), and it was the first finding in 23 cases(50%). The definite diagnosis of polymyositis(PM) was established in 9(19.6%) patients and dermatomyositis(DM) in 4(8.7%) cases, mainly presented in anti-Jo-1 antibody and anti-PL-7 antibody positive patients. Arthritis occurred in 22(47.8%) cases, and it showed higher incidence in anti-Jo-1 and anti-PL-12 antibody positive patients. Raynaud's phenomenon showed only in 9(19.6%) anti-Jo-1 antibody positive patients. Mechanic's hands showed in 20(43.5%) cases, and it showed higher incidence in anti-Jo-1 antibody and anti-OJ antibody positive patients. Fever presented in anti-Jo-1 antibody, anti-EJ antibody and anti-PL-7 antibody positive patients(18, 39.1%). Concomitant tumor was found in 3(6.5%) cases, myocardial damage in 3(6.5%) cases and esophageal involvement in 2(4.3%) cases. All patients were given glucocorticoids(≥ 1 mg/(kg · d)) orally or intravenously, 33 patients received intravenous cyclophosphamide, 4 patients received oral mycophenolate mofetil, 4 patients received oral tacrolimus and 25 patients received intravenous immunoglobulin therapy. Forty-two cases recovered and 4 cases died of respiratory failure. Conclusion Different subtypes of antisynthetase syndrome show the same manifestations, but time of onset and frequency are different, and more than half of the patients have ILD as the first finding. Glucocorticoid is the first-line treatment of ASS, and it is suggested to use with immunosuppressive agents together. If the hormone therapy is ineffective or the disease progresses fast, intravenous immunoglobulin therapy may be considered. Earlier diagnosis and milder ILD at diagnosis predict better prognosis.