Introduction: Anti-PM/Scl antibodies (Anti-PM/Scl) represent a rarely encountered type of antinuclear antibodies. They have mainly been reported in association with idiopathic inflammatory myositis - systemic sclerosis overlap syndromes (also called scleromyositis or sclerodermatomyositis) but also with polymyositis, dermatomyositis and systemic sclerosis without features of overlap syndromes. Studies concerning characteristics of patients with anti-PM/SCl are rare and include small numbers of patients.
Patients and methods: Retrospective review of clinical and biological characteristics of 14 patients with anti-PM/Scl in two University Hospitals: one in Belgium (Erasme Hospital, Bruxelles) and one in France (Hautepierre Hospital, Strasbourg).
Results: Seven patients were identified in Erasme and 7 in Strasbourg: 5 with systemic sclerosis-(dermato)myositis overlap syndromes, 4 with dermatomyositis, 1 with polymyositis, 3 with systemic sclerosis, 1 with primary Sjögren's syndrome. The most frequently observed clinical characteristics (85% of patients) were: pulmonary interstitial disease and arthralgia or arthritis. No patient of our series died or developed cancer (mean follow-up:6.1 years).
Conclusions: Our study failed to identify an homogeneous clinical pattern in patients with anti-PM/Scl, except for 2 characteristics shared by 85% of the patients. This lack of homogeneity is in agreement with preceding literature. We confirm the favourable prognosis associated with the presence of anti-PM/Scl, despite the high incidence of interstitial pulmonary disease. The absence of cancer associated with presence of anti-PM/Scl represents a partial explanation. Finally, we report herein the second case of primary Sjögren's syndrome associated with anti-PM/Scl.