Serial studies of immunocompetence of patients undergoing chemotherapy for acute leukemia

Immunocompetence was followed serially for 1 yr from the onset of treatment in 55 adult patients with acute leukemia. The tests used were delayed hypersensitivity responses to a battery of five recall antigens (dermatophytin, dermatophytin 0, candida, streptokinase streptodornase, and mumps) and in vitro lymphocyte blastogenic responses to phytohemagglutinin and streptolysin 0. There was a strong correlation between immunocompetence at the start of treatment and a good prognosis; 32/39 patients who subsequently entered remission were initially immunocompetent compared to 4/15 who failed to enter remission. In the complete remission group there was a decline in competence starting from 2 to 5 mth after the onset of treatment. In those who remained in remission for 1 yr, competence recovered at 6 mth and remained vigorous thereafter. In those who relapsed before 1 yr, the decline in competence occurred 1 mth before relapse and competence continued to decline progressively during the 1 yr follow up period. These studies suggest that therapeutic approaches which restore immunocompetence or prevent its decline will improve both the remission rate and the remission duration of patients with acute leukemia.