A case of interstitial pneumonia induced by an ACE inhibitor (temocapril hydrochloride)]

A 51-year-old woman who had been treated for years for rheumatoid arthritis presented with a persistent dry cough and shortness of breath three weeks after administration of the ACE inhibitor temocapril hydrochloride against essential hypertension. Chest radiography and computed tomography showed diffuse reticular shadows and ground-grass opacities in both lung fields. Bronchoalveolar lavage fluid analysis showed an increase of lymphocytes and CD8+ T cells (93.3% of lymphocytes), and a decrease of the CD4/8 ratio of the T cell subset (0.04). Histopathological analysis of trans-bronchial lung biopsy specimens showed infiltration of lymphocytes into the alveolar septa and exudation of alveolar macrophages, signs characteristic of interstitial pneumonia. A drug lymphocyte stimulation test was positive for temocapril, but negative for other drugs. On the basis of these findings, we diagnosed temocapril hydrochloride-induced interstitial pneumonia.