Recovery of blood lymphocytes and serum immunoglobulins after treatment of solid tumors in children.

Hematologic and immunologic recovery after treatment for different solid tumors was investigated in 11 children at cessation of therapy and at 1, 3, 6, 9, and 12 months after cessation of therapy by determining blood total leukocyte counts, leukocyte differentials, lymphocyte subsets, concentrations of serum immunoglobulins (Igs), and serum IgG subclasses. Lymphocyte subsets were analyzed from mononuclear cell fractions by flow cytometry and use of monoclonal antibodies CD3, CD20, CD4, CD8, CD4/Leu-8, and CD4/CD45RA. Peripheral blood total leukocyte, neutrophil, and B-cell counts recovered early, although defective B-cell function was seen in several patients. T-cell counts and thus total lymphocyte counts required a longer time to normalize even though inducer T-cell subsets (CD4+CD45RA+ and CD4+Leu-8-) were present in normal or high amounts. CD8+ T cells recovered earlier than CD4+ T cells. The lymphocyte, B-cell and T-cell counts of most patients normalized during the first 12 months after therapy. Recovery of total lymphocyte and T-cell counts was slow in patients with Hodgkin's disease or Burkitt's lymphoma and rapid in nephroblastoma. Radiotherapy seemed to prolong the recovery of study parameters, particularly T-cell recovery.