[Monitoring of cyclosporin A concentration in whole blood with fluorescence polarization immunoassay after bone marrow transplantation].

Cyclosporin A, a strong immunosuppressive agent, has been used to prevent rejection or graft-versus-host disease (GVHD) after organ transplantations including bone marrow transplantations. Monitoring of cyclosporin A concentration in whole blood is necessary for its high frequency of side effects. The authors to measured its concentration by means of radioimmunoassay (RIA) as well as fluorescence polarization Immunoassay (FPIA) a cases after bone marrow transplantation. There was a good correlation between these two methods. FPIA is less specific for cyclosporin A than RIA, but it is an easier method. It is important to measure the concentration of cyclosporin with FPIA because there are metabolites of cyclosporin A which cannot be measured with RIA. Thus FPIA can be applied to the routine monitoring of cyclosporin.