KL-6 as a Possible Monitoring Marker for Hypersensitivity Pneumonitis
A high level of serum KL-6 is known to exist in active pulmonary fibrosis, and KL-6 may be produced and secreted by type II pneumocytes. Herein, we describe a case of hypersensitivity pneumonitis with high serum KL-6 levels. The serum KL-6 level in this 57-year-old woman decreased after admission to our hospital, after avoidance of the causative antigen. It correlated with the severity of symptoms, and reversely correlated with her Pa02 levels and chest x-ray findings. The findings suggest that the serum KL-6 level may increase in such allergic pneumonias as hypersensitivity pneumonitis and that its determination provides a useful indicator and/or monitoring marker of hypersensitivity pneumonitis.