Polymyositis and interstitial lung disease in a patient with anti-Jo1 prototype.

The most common marker autoantibody among patients with polymyositis is anti-Jo1. The patient (John P.) providing the prototype serum for this specificity had both interstitial lung disease and polymyositis. A preliminary survey by Ouchterlony analysis and counter immunoelectrophoresis of serum from 15 patients with idiopathic interstitial lung disease revealed no anti-Jo1 or other precipitating autoantibodies. This provides no evidence to suggest that anti-Jo1 has specificity for interstitial lung disease per se. However, this autoantibody may serve as a possible marker for some patients with overlap of polymyositis and interstitial lung disease. The several interesting features about this patient's diseases and course are discussed.