Ramipril-induced agranulocytosis confirmed by a lymphocyte cytotoxicity test.

A 50-year-old man who had chronic renal failure presented with neutropenic fever four days after ramipril was initiated. Agranulocytosis due to other causes was ruled out after a bone marrow aspiration and biopsy examination were performed. A relationship between the drug and the adverse effect was suggested. It was established by a novel lymphocyte cytotoxicity test.