WHOLE-BLOOD CYCLOSPORINE MONITORING IN LIVER AND HEART-TRANSPLANT PATIENTS - EVALUATION OF THE SPECIFICITY OF A FLUORESCENCE POLARIZATION IMMUNOASSAY AND AN ENZYME-MULTIPLIED IMMUNOASSAY TECHNIQUE

The specificity of two cyclosporin immunoassays were evaluated. Eleven patients were followed for the first four weeks after heart (n = 3) o r liver (n = 8) transplantation. Cyclosporin A (CsA)monitoring was per formed concomitantly by a monoclonal fluorescence polarization immunoa ssay (mFPIA) and enzyme-multiplied immunoassay technique (EMIT(R)) dur ing this period. For several patients, cyclosporin monitoring was also performed by high performance liquid chromatography (HPLC) or by poly clonal fluorescence polarization immunoassay (pFPIA). Liver function w as assessed by follow-up of plasma total bilirubin, gamma-glutamyl tra nsferase and alkaline phosphatase and renal function by plasma creatin ine. All the patients presented episodes of impaired liver function. H igher CsA levels were found using mFPIA measurements as compared to th e EMIT(R) measurements (ratio mFPIA:EMIT(R) (medium range)= 1.4 (1.0-2 .3)). A higher degree of cross-reactivity of the antibody used in the mFPIA as compared to the EMIT(R) was demonstrated by specific measurem ents of CsA and its primary metabolite, AMl, by HPLC. (C) 1997 Publish ed by Elsevier Science B.V.