Clinical manifestations of anti-synthetase syndrome positive for anti-alanyl-tRNA synthetase (anti-PL12) antibodies: a retrospective study of 17 cases

Objective. To describe the clinical manifestations of the anti-synthetase syndrome (ASS) specifically associated with anti-alanyl-tRNA (anti-PL12) synthetase antibodies. Methods. In a retrospective study, 17 patients (eight males, nine females, mean age = 60.3 years) with ASS symptoms confirmed by two consecutive tests (cyto-dot and/or immunoblot, or both), with positive results for anti-PL12 antibodies, were included. Results. All patients presented with interstitial lung disease (ILD), which was associated with mild myositis in 41% of the cases. RP and general impairment were common, whereas rheumatic and dermatological symptoms were uncommon. Four patients suffered from SS, and four others had an atypical oesophageal involvement. The long-term course was assessable for 10 patients (follow-up of 41.1 months). Five patients required immunosuppressive drugs. Two patients are waiting for a lung transplant because of disproportionate and refractory pulmonary hypertension. Conclusion. The severity of anti-PL12 ASS varied because of the constant pulmonary involvement. ILD was the predominant prognosis factor, which was notable in cases associated with pulmonary hypertension.