[Effector function of acute leukemias in "spontaneous" (SCMC) and antibody dependent cellular cytotoxicity-tests...

Blood lymphocytes from 13 untreated acute leukemia patients, 3 pre-leukemias 3 immunoblastic lymphadenopathias and one infectious mononucleosis showed significantly lower spontaneous (SCMC) and antibody-dependent cellular cytotoxicity (ADCC) against 51Cr-labeled allogeneic melanoma cells of the IGR3 cell line than effector lymphocytes from 20 age- and sex matched control persons. While control lymphocytes exhibited the highest cytotoxic activity after depletion of mononuclear phagocytes (Fraction FFF), followed by the "Ficoll" purified Fraction F and defibrinated whole blood, the reverse was true for acute leukemias: here, the highest cytotoxicity was found in whole blood followed by the lymphocyte fractions F and FFF. Comparatively high cytotoxicity was found with two leukemia patients who had received blood transfusions the day before testing. During the course of an acute erythroleukemia chemotherapy drastically reduced SCMC and ADCC activities. A therapeutical splenectomy, on the other hand, did not affect cellular cytotoxicity in the case of a hairy cell leukemia. The angioimmunoblastic lymphadenopathies showed strikingly high percentages of EA- and EAC-rosettes forming cells and showed a marked increase of SCMC and ADCC activities after elimination of mononuclear phagocytes from the effector cell population.