Clinical spectrum and outcomes of patients with anti-jo1 positive antisynthetase syndrome seen at a single tertiary care hospital in North India

Background: Antisynthetase syndrome (ASSD) is a multisystem autoimmune disease characterized by the presence of antibodies against aminoacyl-transfer RNA synthetases, most common being anti-Jo1 antibody. It is an under-recognized entity with a significant delay in diagnosis, both due to lack of awareness of this condition and presentation as “incomplete” form more often than the complete form, characterized by the presence of triad of interstitial lung disease (ILD), myositis, and arthritis. We aimed to study the clinical spectrum and outcomes of anti-Jo1 antibody-positive ASSD at a single tertiary care referral hospital in North India. Methods: Anti-Jo1 positive ASSD patients diagnosed according to the Connors et al. criteria were included in this observational study conducted over 3 years by the departments of Rheumatology and Pulmonary Medicine at a single tertiary care hospital in North India. Results: The clinical spectrum and treatment outcomes of 17 patients diagnosed with anti-Jo1 positive ASSD were studied. Only 2 of the 17 patients presented with the “complete” form at the onset. While 12 patients improved with treatment with steroids and immunosuppressives (mycophenolate, azathioprine, or methotrexate), five patients died, four due to sepsis and one due to progressive lung disease. Conclusion: ASSD is an under-recognized disease, often presenting as an incomplete form rather than the classic triad of arthritis, ILD, and myositis. Infections are the major cause of death contributing to high mortality in Indian patients with ASSD.