DO CYCLOSPORINE PROFILES PROVIDE USEFUL INFORMATION IN THE MANAGEMENTOF RENAL-TRANSPLANT RECIPIENTS

Background. This study investigated the relationships between cyclospo rin A (CsA) blood levels and episodes of renal allograft rejection and nephrotoxicity following renal transplantation, with the aim of estab lishing whether CsA profiles provided more useful information than sin gle CsA blood levels in respect of these relationships. Methods. One h undred and sixty-two profiles were performed over 16 months in 40 pati ents and analysed retrospectively. Blood samples were taken at 0, 2, 4 , 6 and 8 h after the morning CsA dose. Rejection episodes were diagno sed by renal biopsy and CsA nephrotoxicity by a fall in serum creatini ne 1 week after a cut in CsA dose. Results. The mean area under the cu rve (AUG) was lower for profiles performed at the time of rejection (3 821 h.ng/ml) than that of a matched group of non-rejecting profiles (5 479 h.ng/ml; P < 0.02). An AUC above 6400 h.ng/ml significantly discri minated rejection from non-rejection, whereas pre-dose and peak CsA co ncentrations did not have such discriminating cut-off values. A compar ison of CsA-toxic and nontoxic profiles showed that there were no sign ificant differences between mean CsA concentrations nor between the me an AUCs of these groups. Conclusion. We conclude that basing CsA dosin g on CsA profiles could help to avoid some early episodes of rejection without increasing the risk of nephrotoxicity.