Serum KL-6 as a possible marker for amiodarone-induced pulmonary toxicity

Amiodarone is a useful drug for the treatment of life-threatening cardiac arrhythmias. However, amiodarone can induced pulmonary toxicity (APT) and may cause life-threatening lung damage. APT can be difficult to diagnose, but early diagnosis is important. Here, in a 51-year-old man with APT, the high serum KL-6 level was correlated with the severity of symptoms and chest X-ray findings, and it was inversely correlated with PaO2 and diffusion capacity for carbon monoxide levels. The findings suggest that the serum KL-6 level may be increased in APT and that therefore it's the determination of serum KL-6 may provide a useful indicator and/or monitoring marker of APT. KL-6 is believed to be produced and secreted by type II pneumocytes. Typical pathological findings of APT include proliferation of type II pneumocytes which may produce KL-6, and result in increased serum KL-6 levels.