Infectious complications and host immune defense in acute leukemia

Microbiological and immunological studies were carried out on 73 acute leukemia patients in order to establish the relationship between the host immune defense and the frequency and severity of infections. Pronounced disturbances in the functional activity of granulocytes, the total complement hemolytic activity and C₃ component of the complement are found during induction chemotherapy; in this period the infectious complications are more frequent and severe than at the onset of the disease. No relationship is established between serum lysozyme levels and resistance to infections. The elevated immunoglobulins G and M as a possible response to the infectious agents are considered. It is emphasized that a pronounced immunosuppression as well as the most frequent infectious complications are found in patients in relapse.