Children with acute lymphoblastic leukemia show high numbers of CD4(+) and CD8(+) T-cells which are reduced by conventional chemotherapy

Background: Acute lymphoblastic leukemia (ALL) is considered as one of the most common cancer in pediatric malignancies. Among ALL, B-cell Acute Lymphoblastic Leukemia (B-ALL) represents 80% to 85% of the childhood ALL. Problem: Although anti B-ALL chemotherapy kill B-ALL, it associates with alteration in the numbers of CD4(+) and CD8(+) T-cells, and thus impacts the overall immunity. Aim: To evaluate the impact of anti B-ALL on the numbers of CD4(+) and CD8(+) T-cells in correlation to the numbers of CD10(+) B cells in B-ALL pediatric patients. Materials and Methods: Peripheral blood samples were drawn from previously diagnosed B-ALL before (n = 10 cases) and after (n = 10 cases) chemotherapy as well as from healthy controls (n = 10 cases). The numbers of CD4(+), CD8(+) T-cells and CD10(+) B cells were measured in these samples by flow cytometry. Results: As expected, the numbers of CD10(+) B-cells were increased in B-ALL patients before chemotherapy which were associated with increases in the numbers of CD4(+) and CD8(+) T-cells. Chemotherapy of B-ALL patients, during the induction phase, induced dramatic decreases in the numbers of CD 10(+) B cells, which were associated with decreases in the numbers of CD4(+) and CD8(+) T-cells. Tin spite of this alteration, the ratio of CD4/CD8 in B-ALL patients were remained similar before and after chemotherapy as compared to those in healthy controls. Conclusion: Anti B-ALL chemotherapy induces alterations in the frequencies of T-cell subsets. Given the importance of these cells in anti-tumor immunity, our data may lead to further studies to investigate the different subsets of these cells, in particular regulatory T-cells.