CD2 and CD8 expression in acute promyelocytic leukemia

: A 34-year-old man was admitted to our hospital for a headache in March, 1995. The patient's hemoglobin was 7.5 g/dl, platelet count was 1.8 x 10(4)/microliter and white blood cell (WBC) count was 12,400/microliters with 99% myeloblasts. Myeloblasts were agranular or hypogranular but electron microscopy revealed microgranules in cytoplasm, and a few faggots were observed. The bone marrow was hyperplastic due to myeloblasts and chromosomal abnormality was recognized: 46, XY, t(15; 17) (q22; q12). PML-RAR alpha with intron 3 breakpoint of the PML locus, and rearrangements of the T-cell receptor beta and gamma genes were detected. These cells were positive for CD2 (63%), CD8 (47%), CD13 (87%) and CD33 (99%). Microgranular variant type of acute promyelocytic leukemia (APL) was diagnosed. Disseminated intravascular coagulation (DIC) was also present. The patient was treated with enocitabine, daunorubicin, 6-mercaptopurine, dalteparin sodium, anti-thrombin III concentrates and gabexate mesilate with prophylactic frozen transfusions of fresh plasma and platelet transfusions for 5 days, but WBC count did not decrease and DIC did not improve. The patient died of cerebral hemorrhage 7 days after diagnosis of APL. APL with CD8 expression has never been reported. We suggest that therapy should be modified in this type of APL and conclusions concerning the most appropriate therapeutic strategy will depend on the results of treatment of similar cases in the future.