Clinical profile and treatment outcomes in antisynthetase syndrome: a tertiary centre experience

Objectives The aim was to describe the clinical profile and outcomes in patients with antisynthetase syndrome (ASS) from a tertiary care centre. Methods The clinical data and investigations of all patients classified as ASS by Connors criteria over 5years were recorded, and they were followed up prospectively. The median (interquartile range) was used for descriptive statistics. Clinical variables between the Jo-1 and non-Jo-1 groups and between patients with and without anti-Ro52 antibodies were compared using the chi(2) test. Survival analysis was done using the log rank test. Results The 28 patients (23 females) had a median age of 42.5 (34.8-52.3)years, with a disease duration of 1.75 (0.6-3.8)years at diagnosis, and had a follow-up of 2 (0.25-4.25)years. Seronegative arthritis was seen in 23 of 28 patients. Non-specific interstitial pneumonia was seen in 19 patients with interstitial lung disease (ILD). Antibodies to Jo-1 (n=17) were more frequent than non-Jo-1 antibodies (n=11; five anti-PL-12, four anti-PL-7 and two anti-EJ). There was no significant difference in the prevalence of myositis (P=0.07) or ILD (P=0.11) between groups. Anti-Ro52 antibodies were more frequently found in the non-Jo-1 group (P=0.006, =0.51). A partial or complete improvement with treatment was seen in three-quarters of the patients. Five patients succumbed to the illness. Better survival was seen in the Jo-1 group (P=0.05). Conclusion The most typical presenting manifestation of ASS in our cohort was isolated seronegative arthritis. Non-specific interstitial pneumonia was the commonest ILD pattern. Patients with antibodies to Jo-1 had better survival compared with non-Jo-1. The non-Jo-1 aminoacyl-transfer RNA synthetases had a strong association with anti-Ro52 antibodies.