Good outcome of interstitial lung disease in patients with scleroderma associated to anti-PM/Scl antibody

ObjectiveThe objective of this article was to establish the clinical course of interstitial lung disease (ILD) in scleroderma related to the presence of anti-PM/Scl antibody compared with anti-Scl-70 in a Spanish cohort. Furthermore, no study has thoroughly investigated the outcome of pulmonary function test in the first group of patients.MethodsA total of 63 Spanish patients with scleroderma and ILD were selected in a retrospective observational study. Among them, 14 were positive for anti-PM/Scl antibodies and 49 for anti-Scl-70. Clinical assessments, including pulmonary function test, were collected. Variations equal or greater than 10% in forced vital capacity (FVC) were considered significant. Progression-free survival of disease was defined as the period of stable illness since pulmonary fibrosis diagnosis.ResultsAnti-Scl-70 patients had a higher frequency of diffuse SSc subset, peripheral vasculopathy, and gastrointestinal involvement. Inflammatory myopathy was associated to anti-PM/Scl antibody. Anti-PM/Scl patients presented more improvement in FVC during follow-up, 30.8% compared to a 7.1% in Scl-70 group (P = 0.04), with less worsening of this parameter (15.4% vs 52.4% in Scl-70 patients, P = 0.01), and secondary less frequency of severe restrictive pattern (FVC < 50%) (7.7% compared to 42.9% in the other group, P = 0.02). Regarding treatment, more anticalcineurinics were used in anti-PM/Scl patients, while cyclophosphamide and mycophenolate were mainly used in anti-Scl-70 patients. The progression-free survival of disease was higher in anti-PM/Scl patients, with 76% at 10 years from diagnosis of ILD against a 29% in the Scl-70 group.ConclusionsSeveral features and prognosis of ILD in SSc may be modified depending on the identified immunological profile.