[T and B lymphocytes before, during, and after cytostatic therapy of acute lymphoblastic leukemia (ALL) in children (author's transl)].

In 56 children with acute lymphoblastic leukemia (ALL) T and B lymphocytes and immunoglobulins (IgG, IgM, and IgA) were studied before, during, and after therapy. At the time of diagnosis T lymphocytes were normal, the number of B lymphocytes was increased, and immunoglobulins usually were normal. Only two of 30 children had abnormally low immunoglobulin levels. Under therapy a progressive lymphopenia was observed. B cells were depressed most extensively. IgG and IgA levels showed a nadir during early treatment, i.e. after remission induction for IgG and 4-8 months after diagnosis for IgA. IgM was markedly elevated after meningosis prophylaxis. After cessation of therapy lymphocytes increased with an intense rebound of B cells. The recovery was not fully completed after one year free of therapy.