EARLY RECOVERY OF CD4-LYMPHOCYTES IN CHILDREN ON HIGHLY-ACTIVE ANTIRETROVIRAL THERAPY( T)

Introduction: Regeneration of CD4+ T lymphocytes has been shown to be thymus-dependent in bone man ow transplant recipients and after intens ive chemotherapy. The rate of CD4+ T cell regeneration is correlated p ositively with enlargement of the thymus, as shown on radiographs, and higher rates of CD4+ T lymphocyte regeneration were observed in child ren as compared with adults, consistent with thymic function diminishi ng with ape. We hypothesized that in HIV infected patients CD4+ T cell recovery during highly active antiretroviral therapy (HAART) may also be thymus dependent. Therefore, repopulation of naive (CD45RA+), memo ry (CD45RO+) and total CD4+ T lymphocytes and total CD8+ T lymphocytes in peripheral blood was assessed in 13 HIV infected children during t he initial 3 months of HAART. Results: Significantly higher recovery r ates of naive, memory and total CD4+ T cells were observed in children below the age of 3 years as compared with older children. Kinetics of total CD8+ T cells showed no relation to ape. Moreover, recovery rate s of naive CD4+ T cells in patients below 3 years of age were 10-40 fo ld higher as compared with previously reported naive CD4+ T cell recov ery rates in adults on HAART. Conclusions: High recovery rates of naiv e, memory and total CD4+ T cells can be achieved in children below 3 y ears of age. Changes in CD8 counts did not correlate with age. These r esults indicate;hat regeneration of CD4+ T cells during HAART may be a thymus-dependent process. (C) 1998 Lippincott Williams & Wilkins