Platelet function in acute leukemias.

: Bleeding time, clot retraction, platelet factor 3 availability and platelet aggregation in response to ADP, epinephrine, collagen and ristocetin were studied in 13 cases of acute leukemia which included 5 cases of acute myeloid leukemia, 2 of chronic myeloid leukemia in blast crisis and 6 of acute lymphoblastic leukemia. More than one abnormality was seen in all the patients. Defects in bleeding time, clot retraction and platelet factor 3 availability were encountered in 43% of cases. Platelet aggregation responses to all the reagents were significantly impaired. There was, however, no consistency in the pattern of the defects.