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

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 (C (0) ) 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 florescence polarization immunoassay (TDx). Mean CyA C (0) and C (2) concentrations were calculated. Logistic regression analysis revealed that mean C (2) level was the only predictor of acute rejection (P less than or equal to 0.001). Higher mean C (2) levels predicted lower rejection probabilities. Linear regression analysis revealed that higher mean C (2) levels were not related to higher serum creatinine levels at either week 4 or 24 or to incidence of headache or tremor. The CyA C (2) levels predict the frequency of rejection postrenal transplant. Target C (2) levels are in the range of 1500 ng/dL.