Cyclosporine serum concentrations soon after heart or heart-lung transplantation

The accumulation of cyclosporine was evaluated in 11 patients following either heart or heart-lung transplantation. Blood samples were drawn frequently for the first few postoperative days, and the plasma was analyzed by both radioimmunoassay (RIA) and high-performance liquid chromatography (HPLC). The levels determined by RIA were higher than those assessed by HPLC, and it is hypothesized that the difference is due to antibody reactive metabolites of cyclosporine, which are measured by the RIA procedure. We did not find any consistent trends in the accumulation of these metabolites. Analysis of early clinical data did not suggest any relationship between levels of cyclosporine or its metabolites and clinical outcome.