Abstract
The expression of CD25 and CD45RO in lymphocytes from patients with acute lymphoblastic leukemia in response to cytomegalovirus and varicella-zoster virus antigens was analyzed by flow cytometry. It is suggested that the defects in the immune response to cytomegalovirus and varicella-zoster virus in patients with acute lymphoblastic leukemia on chemotherapy are in the expression of CD25 and in the switching of CD45RA cells to CD45RO cells.