Immune status in children with acute lymphocytic leukemia. Observations in 67 cases

67 children affected with acute lympocytic leukemia were immunologically evaluated for lymphocytic markers, serum immunoglobulins and delayed hypersensitivity skin tests at the onset, in remission and after cessation of therapy. E, EA rosettes and surface Ig assayed significantly lower in leukemic children than in matched controls, except for three cases of T-cell leukemia in which E rosettes were very high. After cessation of therapy almost normal results were obtained. As for serum Ig, the only abnormal finding was that of low IgM during therapy. The skin tests with Varidase, Candidine, Mumps antigen and DNCB were not significantly different at onset and in remission. As for DNCB test, the negative responses at onset often became positive in remission, but only when the test was performed before any treatment (anamnestic-like response?). One of the three patients with T-cell leukemia relapsed after 8 months: strangely enough, no surface marker could be detected on that occasion. We could not find any relationship between various immunological tests, or between these tests and prognosis; chemotherapy proved active in suppressing cellular immunity, especially the primary cellular response.