Haemagglutinin production in tumour‐bearing and leukaemic mice

Time‐course studies on anti‐sheep erythrocyte haemagglutinin formation after a single injection of antigen in tumour‐bearing and leukaemic mice yielded the following results: 1) Mice bearing (a) transplanted Ehrlich carcinoma or (b) primary mammary adenocarcinoma exhibited normal humoral antibody responses irrespective of the stage of tumour growth and the condition of the tumour‐bearing animal; 2) Rauscher leukaemic mice, on the other hand, showed marked abnormalities in antibody‐producing capacity. Sequential measurements revealed an increasing degree of immunodepression as the leukaemia progressed. However, the impairment of antibody production was already increased appreciably during the first aleukaemic phase of Rauscher disease 10 days after inoculation with the leukaemic virus; this was followed, during the second leukaemic phase, by a slight return of haemagglutinin‐forming capacity although not to normal levels. The terminal leukaemic stage was characterized by the strongest immunodepression recorded in the course of Rauscher disease. All leukaemic mice eventually exhibited a late immunodepression approximately 30 days after immunization. The various degrees of qualitatively and quantitatively differing immunological abnormalities are discussed in relation to the pathogenesis of Rauscher disease.