Interstitial lung disease associated with the antisynthetase syndrome

A never-smoker 40-year-old obese woman complained of progressive dyspnea and cough for the past year. A chest high-resolution computed tomography showed lower lobe predominant peripheral reticulation with extensive ground-glass opacities, traction bronchiectasis, and areas of subpleural sparing. Pulmonary function tests demonstrated moderate restriction and gas transfer defect. A low-titer antinuclear antibody (ANA) test with cytoplasmic pattern was found, whereas a surgical lung biopsy was interpreted as an unclassifiable pattern of fibrosis with lymphocytic inflammation with occasional giant cells. The patient was placed empirically on prednisone and referred to the interstitial lung disease (ILD) clinic for further evaluation. At the presentation to the ILD clinic, she also reported morning stiffness without obvious joint swelling. Doctors noticed “mechanic’s hands” with digital fissuring and hyperkeratosis. whereas her myositis autoantibody panel showed a positive anti–PL-12 antibody. The patient was diagnosed with an antisynthetase syndrome and put on mycophenolate mofetil as steroid-sparing agent. Prednisone was tapered off, and she underwent pulmonary rehabilitation. In a 1-year follow-up, her lung function and exercise capacity improved. Through the description of this clinical case, the chapter deals with the diagnosis and management of ILD associated with antisynthetase syndrome and more generally with idiopathic inflammatory myopathies.