Perforin-positive leukemic cell infiltration in the heart of a patient with T-cell prolymphocytic leukemia.

Here we report a rare case of T-cell prolymphocytic leukemia in whom leukemic killer cells, expressing a cytolytic factor perforin, infiltrated the heart. Perforin may have directly injured myocardial cells which showed marked expression of human leukocyte antigens (HLAs) and intercellular adhesion molecule-1 (ICAM-1) as well as costimulatory molecules B7 and B70, which are ligands for CD28 expressed on T-cells. In spite of chemotherapy against leukemic cells, this autoimmune process finally caused fatal congestive heart failure.