INTRACELLULAR CYTOKINE PROFILE OF CORD AND ADULT-BLOOD LYMPHOCYTES

Umbilical cord blood (CB) transplantation is thought to be associated with a reduced risk of severe graft-versus-host-disease (GVHD) compare d with bone marrow transplantation (BMT), The cytokine cascade is know n to be important in the pathogenesis of GVHD; however, previous studi es investigating the cytokine secretion pattern of CB cells have been contradictory because of variations in experimental techniques. In thi s study, the cytokine profile of cord and adult blood lymphocytes and lymphocyte subsets has been assessed at the single cell level by flow cytometry, using CD4/CD8 and CD45RA/CD45RO markers. Cord and adult blo od mononuclear cells were stimulated with phorbol 12-myristate 13-acet ate (PMA) and ionomycin in the presence of monensin, After 4 to 24 hou rs of incubation, interleukin-2 (IL-2), IL-4, interferon-gamma (IFN-ga mma), and tumor necrosis factor-alpha (TNF-alpha) production was measu red by three-color flow cytometry, The results show that cord blood ly mphocytes (CBL) produce less IL-2, IL-4, IFN-gamma, and TNF-alpha than adult peripheral blood lymphocytes (ABL), Further subset analysis sho wed that in CBL the majority of cytokine producing cells were CD4(+)CD 45RA(+), whereas in ABL the cytokine-producing cells were both CD4(+)C D45RO(+) and CD8(+)CD45RO(+). These results suggest that the reduced i ncidence of GVHD in CB transplantation may partly due to the altered c ytokine profile seen in CBL. (C) 1998 by The American Society of Hemat ology.