No abstract

No abstract

In the absence of clinically relevant models of acute rejection we have attempted to develop an assay to measure cyclosporine-resistant allospecific cytotoxic cells in vitro, beginning at birth. The principle of limiting dilution analysis was applied to investigate umbilical cord bloods as responders. Responders were incubated for 1 h in different concentrations of cyclosporine and irradiated HLA mismatched stimulator cells from healthy adults added, followed by recombinant IL-2. After 7 days, responders were tested against three europium-labelled PHA blasts: stimulator, responder and third party. A significant number of cyclosporine-resistant allospecific cytotoxic cell precursors were found in cord blood indicating prior activation. They may have been primed in utero against non-inherited maternal HLA antigens. Cyclosporine-resistant allospecific cytotoxic cell precursors were demonstrated in human umbilical cord blood using a quantitative assay. These cells may influence the reaction to subsequent transplants.