Antiphospholipid and antisynthetase syndrome in a patient with polymyositis-rheumatoid arthritis overlap.

Idiopathic inflammatory myopathies, mainly polymyositis (PM) may occur in the course of several autoimmune diseases. The overlapping forms of myositis, when the patient also meets the criteria for rheumatoid arthritis (RA), affect 3%-5% of myositis patients [1]. To the best of our knowledge this is the first report on the overlapping form of RA, antiphospholipid syndrome (APS) and the serological subgroup of PM, the antisynthetase syndrome (ASS).