Two-hour post-dose cyclosporine level is a better predictor than trough level of acute rejection of renal allografts

Abstract

Cyclosporine (CyA) trough concentrations are poor predictors for acute rejection post-transplant. Patients were part of a randomized trial of basiliximab (n=70) vs. anti-thymocyte globulin (ATGAM) (n=65), both in combination with Neoral, mycophenolate mofetil, and steroids, undergoing first or second, cadaveric or live donor renal transplants. Whole blood samples were collected just before (C0) and at 2 h after CyA dosing on day 4 and at the end of weeks 1, 2, 4, and 8. The CyA was measured by fluorescence polarization immunoassay (TDx). Mean CyA C0 and C2 concentrations were calculated. Logistic regression analysis revealed that mean C2 level was the only predictor of acute rejection (P < or = 0.001). Higher mean C2 levels predicted lower rejection probabilities. Linear regression analysis revealed that higher mean C2 levels were not related to higher serum creatinine levels at either week 4 or 24 or to incidence of headache or tremor. The CyA C2 levels predict the frequency of rejection postrenal transplant. Target C2 levels are in the range of 1500 ng/dL.