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 5 years 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 χ2 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, ϕ = 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.
Keywords: anti-Jo-1; antisynthetase; interstitial lung disease; myositis; seronegative arthritis.
© The Author(s) 2021. Published by Oxford University Press on behalf of the British Society for Rheumatology.