[Is cellular immunity not impaired after remission induction in acute lymphoblastic leukemia in children]

We examined immune system at the time of diagnosis and after remission induction in the group of 30 children (aged 6.5 +/- 3.6) with acute pre-B lymphoblastic leukaemia (ALL). The group was divided into standard risk group (treated with BFM protocol, n = 20) and high risk group (New York protocol, n = 10). We measured: episodes of infection, leukocytosis, immunoglobulin concentrations (G, M, A and E), lymphocytes and their subpopulations (CD19+, CD3+, CD3 + HLA-DR+, CD4+, CD8+, CD4 + CD45RA+, CD4 + CD45RO+, CD8 + CD45RA+, CD8 + CD45RO+, CD16 + CD56+).

Immunoglobulin concentrations at the time of diagnosis were normal, and decreased after remission induction only reduction of IgG concentration was statistically significant (p = 0.008). At the time of diagnosis we noted the following differences in examined group compared to control group: higher leukocytosis (p = 0.03), lower lymphocyte count (p = 0.0008), significantly lower lymphocyte subpopulation count (for subpopulations CD19+; CD3+; CD4+; CD8+ and CD16 + 56+). After remission induction comparing to the time of diagnosis we observed: total leukocytosis reduction (p = 0.01), percentage and count CD19+ lymphocytes reduction (adequately p = 0.000007, p = 0.03), increase of lymphocyte CD3+ percentage (p = 0.002) and CD8+ lymphocyte percentage (p = 0.00003).

1. At the time of diagnosis of acute lymphoblastic leukaemia in children lower counts of all lymphocyte populations are observed. 2. Immune suppression after remission induction in this group of patients concerns mainly humoral response, particularly immunoglobulin G production. 3. Severe infections in patients treated for acute lymphoblastic leukaemia are indication to immunological system assessment and early immunoglobulin supplementations of deficits e.g. immunoglobulin infusions. 4. Humoral immunity impairment in children with ALL is an effect of treatment, not disease.