Spontaneous regression of Friend virus-induced erythroleukemia IX. Role of complement in leukemia regression.

The role of complement was examined in the immunologically-mediated spontaneous regression of erythroleukemia induced by the RFV strain of the Friend virus complex. Hemolytic complement levels were not significantly altered during the leukemic, regressed and recurrent phases of the disease. No correlation was observed between leukemia regression and complement levels in normal, C5-deficient and hybrid mice. No correlation was observed between serum complement activity and leukemia recurrence or mortality due to leukemia. The data suggest that hemolytic complement, and thus those immune effector functions specifically dependent on full complement activity, are not involved in leukemia regression and do not influence the course of the disease.