Immune recovery of children with cancer after the completion of therapy

We prospectively evaluated the immune status and the rate of immune recovery in children with cancer treated with chemotherapy(CT) and/or radiotherapy(RT). Of the 128 children studied, 72 had ALL , 22 lymphoma , 14 sarcoma and 20 had various types of tumors. Evaluation of humoral immunity included serum IgG, IgA and IgM levels studied by nephelometry. Qualitative and quantitative evaluation of humoral responses to previous immunizations included serum antibody levels to mumps and measles (qualitative) and to rubella and polio (quantitative). Furthermore, skin tests (volar forearm) for responsiveness to candida, trichophyton, tetanus toxoid (cellular immunity) and diphtheria toxin (humoral immunity), were performed. Induration and erythema were measured 48 and 72 hours after application of the immunogen. Positive skin test was defined as an induration of 2mm diameter or more. Measurement of cellular immune responses included enumerating lymphocyte subpopulations by flow cytometry using a FACScan instrument (Becton-Dickinson, Mountain View, CA). The lymphocyte subgroups were identified using: CD3, CD4, CD8, CD16, CD19, CD3HLA DR, CD45RO and CD45RA. The CD4/CD8 ratios were determined as well. The results were expressed by median values and were analyzed using the non-parametric Mann Whitney U test. Patients with primary immunodeficiency , patients transplanted in first or subsequent remission were excluded as were children experiencing relapse of their disease. Children were evaluated at the time of completion of CT and 6 monthly thereafter. Children with ALL were evaluated at the end of the intensive part of the protocol prior to the onset of maintenance as well