Characterization of dermatomyositis with coexistence of anti-Jo-1 and anti-SRP antibodies.

We describe a patient with dermatomyositis who presented with rapidly developing severe muscle weakness complicated by massive pleural effusion with interstitial lung disease. Myopathological analysis was suggestive of dermatomyositis. This patient showed both anti-Jo-1 and anti-SRP antibodies in serum. To our knowledge, the coexistence of these two myositis-specific autoantibodies (MSA) is considered extremely rare and is clearly an exception to the rule of having only one MSA. Our findings provide compelling evidence that the coexistence of these two MSAs may lead to more severe clinical symptoms, interacting in a complex fashion, thus expanding the clinical spectrum of idiopathic inflammatory myopathy.