Impact of treatment reduction for childhood acute lymphoblastic leukemia on serum immunoglobulins and antibodies against vaccine-preventable diseases

Background: The consequences of current intensive chemotherapy for childhood acute lymphoblastic leukemia (ALL) for immune defense are a matter of concern. The purpose of this study was to examine the effect of reduced compared with intensive (conventional) ALL chemotherapy on serum immunoglobulin levels and specific antibody concentrations against vaccine-preventable diseases. Procedure: Patients treated according to Dutch Childhood Oncology Group ALL 10 protocol were stratified by minimal residual disease to receive reduced (standard risk; SR) or intensive (medium risk; MR) intensification/maintenance treatment. Between November 2004 and July 2009 we compared serum immunoglobulins of 110 patients and specific antibodies against diphtheria toxin, tetanus toxin, and Bordetella pertussis antigens of 41 patients of SR and MR groups during chemotherapy. Results: Immunoglobulin levels showed significantly different patterns between the SR and MR groups. In the MR group IgG, IgA, and IgM levels decreased towards the end of intensive treatment; in the SR group IgG levels increased while IgA and IgM stabilized. In both groups IgM and IgG levels were most affected. Specific antibody levels against vaccine-preventable diseases decreased in both groups, but more profound in MR group. Conclusions: Although reduced chemotherapy is beneficial for immunoglobulin level recovery and might prevent susceptibility for infections, specific antibodies remain decreased.