1. Employing the technic of specific mixed cell agglutination (SMCA), it has been demonstrated that leukemic lymphocytes, as well as red cells, may be coated with globulins which are reactive with antihuman (Coombs) serum.
2. Moreover, in vitro, these proteins may dissociate from neoplastic lymphocytes and reassociate on normal erythrocytes rendering them Coombs-positive.
3. The dissociation-reassociation phenomenon appears to be time- and temperature-dependent and may be augmented by complement or a related heat-labile serum or cell factor.
4. It is suggested, by analogy to instances in which the normal lymphocyte mediates certain immunologic reactions, that the neoplastic lymphocyte may participate actively in the acquired hemolytic anemia of chronic lymphocytic leukemia.