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

Here we report a rare case of T-cell prolymphocytic leukemia in which leukemic killer cells, expressing a cytolytic factor perforin, infiltrated the aorta as well as the heart and may have directly injured aortic vascular cells which strongly expressed 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 multi-organ failure.