Increased Serum KL-6 Levels Induced by Pulmonary Mycobacterium Avium Complex Infection in a Patient with RA-associated Lung Disease.

KL-6 is a glycoprotein found predominantly on type II pneumocytes and alveolar macrophages, and often shows increased serum levels in patients with interstitial pneumonia. We report a case of mycobacterium avium complex (MAC) infection whose disease activity was correlated with KL-6 levels in serum. During treatment of rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) with prednisolone, chest image findings improved in...