Cord blood serum does not increase lymphocyte responses in comparison to adult serum

To date, over 1000 cord blood (CB) transplants have been reported from diff erent centers worldwide and ie is generally agreed that CB represents an en couraging alternative eo bone marrow (BM) transplantation. There are a vari ety of reasons for this, however, possibly the two most controversial aspec ts are (a) whether there is less graft versus host disease (GVHD) with CB c ompared to BM transplantation, and (b) whether we can use more HLA mismatch es with CB transplantation. The major theory regarding the reduced immunolo gical response of CB lymphocytes is that CB T and NK cells are naive and, t herefore, not primed for activation. However, the naive phenomena that has been noted in vitro may be bypassed in vivo by unforeseen fact:ors. We show evidence that there are differences in the soluble factors present in CB a nd adult serum and that these differences play a role in T cell function. T hus, adult serum will enhance both mitogen and IL-2 specific T cell growth whereas CB serum has no effect, suggesting that there is an activation/ gro wth factor present in adult sera, which is absent in CB sera, This work cou ld enable us eo identify the molecular mechanisms which are associated with a lower GVHD in CB compared eo BM transplanted individuals. Human Immunolo gy 61, 111-114 (2000). (C) American Society for Histocompatibility and Immu nogenetics, 2000. Published by Elsevier Science Inc.