Immunological recovery in children with ALL at the end of intensive therapy, at the completion of therapy, and up to one year off therapy. A follow-up study

Abstract

9031 Background: Children undergoing therapy for ALL are known to have impaired immune function. (ASCO 2005, abstract #8541). Methods: We prospectively evaluated the humoral and cellular immunity in children with ALL at the end of intensive therapy (Evaluation 1 -E1) and values were compared to those at the completion of therapy (E2), at 6 months (E3) and at 12 months thereafter (E4). Investigations among others included CBC, lymphocyte subpopulation by flow cytometry (CD3, CD4, CD8, CD16, CD19, CD3 DR, CD45RO and CD45RA), immunoglobulin levels by nephelometry, antibody titers to MMR immunization and skin tests to Candida, Trichophyton, diphtheria toxin and tetanus toxoid. Seventy three children with ALL, 48 boys, 25 girls (median age 4 years on diagnosis) treated according to BFM 95 protocol were evaluated. Of the 139 evaluations, 41 were E1, 43 E2, 37 E3, 18 E4 and data were analyzed with a non parametric Mann Whitney test. Results: Immunoglobulin levels at E1 were low in the majority of children and were increasing at E2 and E3 and E4 for IgA and IgM (median values of parameters studied are shown in the table in mg/dl for immunoglobulins and % for CD’s). Of the 70 children immunized with MMR only 11 had absent IgG antibodies. Also, skin tests were positive for tetanus toxoid in 93/139 evaluations, for candida in 41/139 and negative for trichophyton and diphtheria toxin. Conclusions: Children with leukemia experience severe immunological damage after intensive therapy which is gradually improving overtime although some values remain abnormal 6 months after the completion of therapy. It is worth mentioning that despite impaired immune function serious infections were not documented after the first six months of intensive therapy. [Table: see text] No significant financial relationships to disclose.