Jo1-antisynthetase syndrome and severe interstitial lung disease with organising pneumonia on histopathology with favourable outcome on early combined treatment with corticosteroids, mycophenolate mofetil and rituximab.

Antisynthetase syndrome is a rare autoimmune disease and represents a distinct entity within the idiopathic inflammatory myopathies. Its variable systemic manifestations are composed of myositis, interstitial lung disease, non-erosive arthritis, fever, Raynaud's phenomenon, hyperkeratotic skin changes and the presence of antibodies against aminoacyl-transfer-RNA-synthetases. Interstitial lung disease is the major determinant of morbidity and mortality. The role of lung biopsy remains controversial but it might be considered on an individual basis and may provide information regarding prognosis and treatment response. An integrated clinical, radiological and pathological approach to interstitial lung disease has to be emphasised. Due to the rarity of the disease, no standardised treatment guidelines for antisynthetase syndrome exist. We discuss a patient with anti-Jo1-autoantibody antisynthetase syndrome with proximal myositis and severe, rapid onset, interstitial lung disease with a histopathological pattern of organising pneumonia on surgical lung biopsy and good response to early combined immunosuppressive treatment with corticosteroids, mycophenolate mofetil and rituximab. © BMJ Publishing Group Limited 2019. No commercial re-use. See rights and permissions. Published by BMJ.