抄録
In vitro functional studies were performed on peripheral blood lymphocytes obtained from the patients with lymphocytic leukemia to determine 1) proliferative response to PHA assayed by the uptake of 3H-thymidine incorporation into DNA, 2) PHA-induced cell-mediated cytotoxicity (PICC) and 3) antibody-dependent cell-mediated cytotoxicity (ADCC). In the lymphocytes from leukemic patients, both proliferative response to PHA and the PICC were markedly depressed in comparison with those from normal subjects. The ADCC was also generally depressed except for one case of T-CLL, in which the ADCC activity was as high as in the normal subjects. From this particular case characterized by also the presence of a comparatively large number of For R (+) cells, it is saggested that leukenic Tγ cells may posses the effector function in ADCC. In every other cases, no correlation was found between number of E-RFC and PICC, and between Fcγ R (+) cells and ADCC. Scanning electron microscopic observation on ADCC of leukemic lymphocytes from a case of HCL revealed a little or no destruction of the target cells and a complete absence of hairy cells around the target cells. These findings suggest a possibility that the malignant cells are completely lack the potential for cytotoxic functions. Therefore, the existence of ADCC and PICC activties, however markedly depressed, in the periferal lymphocytes from the leukemic patients could reflect the residual presence of normal lymphocytes.
