[A case of valsartan-induced pneumonitis with marked elevation of serum KL-6].

A 64-year-old man, who had been treated with valsartan for hypertension since about 2 months previously, was admitted with exertional dyspnea. A chest X-ray film on admission showed infiltrative shadows in bilateral lower lung fields. Chest computed tomographic images showed diffuse ground-glass opacities, consolidation and traction bronchiectasis. His serum KL-6 level was markedly elevated, to 7,360 U/ml. Despite the withdrawal of valsartan, his symptoms deteriorated, and a drug lymphocyte stimulation test was positive for valsartan. Based on these findings, we diagnosed valsartan-induced pneumonitis. Glucocorticoids were administered, and his symptoms, chest radiograph findings and serum KL-6 level all improved. Currently, angiotensin II receptor blockers (ARBs), including valsartan, are often used as the first drug of choice to treat hypertension, but they can cause drug-induced pneumonitis. It has been previously reported that serum KL-6 levels may reflect the clinical activity of drug-induced pneumonitis. In cases of drug-induced pneumonitis with a high level of serum KL-6, glucocorticolds should be started at an early stage.