EVALUATION OF CELLULAR AND HUMORAL IMMUNE RESPONSE FOLLOWING INFECTION OR VACCINATION IN CHILDREN WITH MALIGNANCY AFTER COMPLETION OF CHEMOTHERAPY.

A. Russo, J. Faber, P. Habermehl, M. Dittrich, D. Klotz, M. Knuf, C. Meyer, H.J Schmitt, F. Zepp

Centre of Preventive Paediatrics, University Children's Hospital Mainz, Germany

Purpose: To investigate the extent of cellular and humoral immune alterations in children with malignancies after cessation of chemotherapy (CTX). Methods: Applying standard immune assays, cellular and humoral immunity against varicella, mumps, diphtheria, measles, pertussis and tetanus antigens were measured in 52 children (1-17 years of age) with various malignancies 1 - 96 months after CTX. Using a standardised questionnaire vaccinations before CTX and natural infections were solicited. Results: All children had at least received DT-OPV before entering CTX. In these children the proliferative response rates against vaccine antigens were significantly reduced post CTX. 1,5 years after CTX serum antibody concentrations were low in 16/19 patients. Revaccination at this point resulted in significant antibody rises. Nevertheless one patient developed rubella 1 year after revaccination. From 29 patients with documented natural infections (22 VZV, 3 pertussis, 5 measles, 1 rubella) before CTX but ”non vaccinated status” all had sufficient cellular and humoral immune response 6 months after therapy. Patients with neither previous natural infections nor sufficient vaccination before CTX developed severe clinical disease up to 4 years after CTX (8 chickenpox, 9 zoster, 5 pertussis, 1 mumps, 1 rubella). Conclusion: Children with cancer have persistent humoral and cellular immune deficiencies up to at least 4 years after completion of CTX rendering them susceptible to vaccine preventable diseases. A prospective multicentre based study was set up to further evaluate the clinical significance of these findings.