Decreased numbers of CD4+ T lymphocytes in peripheral blood after treatment of childhood acute lymphoblastic leukemia.

Treatment-related immunosuppression in patients with acute lymphoblastic leukemia (ALL) is associated with increased susceptibility to infectious diseases, also after the treatment. The aim of the present study was the detailed evaluation of T lymphocyte subsets in peripheral blood in children after treatment of ALL. All children were treated according to the BFM 90 protocol. The patients were divided into 5 groups of 30 children in each, depending on the time from cessation of the ALL treatment. A control group consisted of 30 healthy children subjected to elective "1-day" surgery. The children's age ranged from 6 to 18 years. The examinations were performed in FACScan flow cytometer with the use of wide set of monoclonal antibodies: CD3, CD4, CD8, TCRalphabeta, TCRgammadelta, CD19, CD25, CD45RA, CD45RO, CD69, HLA-DR, CD16 and CD56, which particularly allowed detailed analysis of T lymphocytes. The results showed that most parameters in children 1 year after ALL treatment completion were similar to healthy children. However, we observed persistently low CD4+ T cell numbers, both CD45RA+ as well as CD45RO+ subsets as compared to the control group. This might reflect decreased regenerative potential of immunological system in children 1 year after ALL treatment.