Prediction Significance of Lymphocyte Subsets for Response to Chemotherapy in Children with Acute Myeloid Leukemia

Background. The objective of this study was to evaluate quantitative changes of B, NK and T lymphocyte subsets in peripheral blood and their predictive significance in children with acute myeloid leukaemia (AML) under chemotherapy in Centre for pediatric oncology and hematology, Children‘s Hospital, affiliate of Vilnius University Hospital “Santariškių Klinikos”.

Patients and methods. Children with AML were treated according to NOPHO - DBH 2012 protocol and ML DS 2006. Levels of B lymphocytes (CD19⁺), NK cells (CD3^-CD56⁺) and subsets of T lymphocytes  (CD3⁺CD4⁺, CD4+CD25+Foxp3 + ,CD3 + CD8 + ,CD3+CD8+CD57+, CD3+CD8+CD57') in peripheral blood were anal ysed by flow cytometry before treatment and in 22^nd day after treatment with cytotoxic drugs.

Results. Immunological analyses has been performed for 8 children with AML (average age - 46 months (range - from 8 to 133 months)). In pre-treatment period the amount of CD3+CD4+ lymphocytes in children with poor response to treatment was more than 5979 cells/mkL compared to children with good treatment response (less 4346 cells/mkL). The amount of CD3+CD8+CD57" lymphocytes in children with poor response to treatment before chemotherapy was higher (3711 cells/mkL) than of those with good re­sponse to treatment (less 3200 cells/mkL). Prior to treatment of T-regul atory lymphocyte counts in children with poor response to treatment were higher than 148 cells/mkL in comparison to those with good treatment response (less 45 cells/mkL).

Conclusions. The amount of B lym­phocytes and NK cells didn’t differ between children with good and poor response to treatment. Levels of CD3⁺CD4⁺ and CD4⁺CD25⁺FoxP3⁺ lymphocytes prior to treatment were significantly lower in children with good response to treatment compared to poor response group. The amount of CD3⁺CD8⁺CD57^- lymphocytes in pre-treatment period in children with good treatment response was lower than with poor treatment response. However, the amount of these lymphocytes has decreased significantly for children with poor response after treatment with cytotoxic drugs.