Pulmonary pathologic manifestations of anti-glycyl-tRNA synthetase (anti-EJ)-related inflammatory myopathy

Antisynthetase syndromes are a subset of the idiopathic inflammatory myopathies characterised by the presence of autoantibodies to aminoacyl transfer-RNA synthetases (ARS) and monotypic clinical features including Raynaud phenomenon, fever, non-erosive inflammatory arthritis and hyperkeratotic skin changes ('mechanic's hands'). Interstitial lung disease (ILD) is particularly common in ARS syndromes, affecting up to 90% of patients.

Four patients with ARS syndrome who possessed anti-glycyl-tRNA synthetase (anti-EJ) autoantibodies were retrieved from the University of Pittsburgh database. We report their clinical, radiographic and histopathologic findings.

Patients presented with dyspnoea accompanied by Raynaud phenomenon and 'mechanic's hands'. Lung disease was the first manifestation in all four patients (100%) who were all amyopathic. High-resolution CT of the chest showed patchy opacities and consolidations in two patients (50%) whose surgical lung biopsies revealed organising diffuse alveolar damage (DAD), and lower lung zone predominant reticular infiltrates and traction bronchiectasis without honeycomb change in two patients (50%) whose surgical lung biopsies revealed usual interstitial pneumonia (UIP). Mild lymphoplasmacytic inflammation and few scattered lymphoid aggregates were present, but we found no pathognomonic histopathologic features of anti-EJ ARS syndrome. Serologic testing revealed no other autoantibodies. All patients responded to immunosuppressive therapy.

Identifying ARS-associated autoantibodies in ILD patients with or without myopathy is desirable because patients may respond well to immunosuppressive therapy, and their prognosis is better than that of patients with idiopathic forms of DAD or UIP.