Kivonat:
In this study we analyzed the recovery of the immune system in children after completion of the therapy. We analysed 88 children (51 boys, 37 girls, mean age at diagnosis: 7.8 years) receiving chemotherapy for malignant diseases (43 acute lymphoblastic leukemia, 15 lymphoma, 20 bone tumor, ten other solid tumors). Serum immunoglobulin levels (Ig), natural killer activity (NK), antibody-dependent cellular cytotoxicity (ADCC) and T and B cell proliferation were determined 1 year after cessation of therapy. The mean levels of Ig were in the normal range at a mean of 13 months after chemotherapy (IgG: 11.2 +/- 3.3, IgA: 1.6 +/- 0.9, IgM: 1.0 +/- 0.5 g/l), however in the leukemic patients serum IgG was below the lower limit of the normal range in 3/43 (7.0%) cases, serum IgA was low in 5/43 (11.6%) and serum IgM was decreased in 4/43 (9.3%) cases. In the solid tumor patients IgG values were within the normal range and only 2-2/45 children had lower values for IgA and IgM (4.4%). NK activity decreased in 7/43 (16.3%) leukemic patients, and in 3/45 (6.7%) solid tumor patients, ADCC decreased in 8/43 (18.6%) and 3/45 (6.7%), respectively (p < 0.001). B-cell blastic transformation was decreased in 3/43 (7%) leukemic patients and in 4/45 (8.9%) solid tumor patients. At the same time T-cell blastic transformation was altered in 5/43 (11.6%) and in 4/45 (8.9%) cases, respectively. Leukemic patients had significantly more infections during the first year after chemotherapy than solid tumor patients (1.60 +/- 1.18 vs 0.96 +/- 1.14; p = 0.011). No significant correlations could be found between the investigated immune parameters and the number and severity of infections. It is concluded, that cytotoxic therapy can lead to long-term depression of the immune system, first of all in leukemic patients.
