THE EFFICACY, SAFETY, AND FEASIBILITY OF LONG-TERM TWO-HOUR CYCLOSPORINE LEVEL MONITORING IN AFRICAN AMERICAN RENAL TRANSPLANT PATIENTS

Abstract

P203 Aims: (1) Evaluate the impact of two-hour cyclosporine level (C2) monitoring in stable, maintenance-phase African American cadaveric renal transplant patients. (2) Establish the safety of the two-hour cyclosporine target range 800-1200 ng/ml in African American cadaveric renal transplant recipients. Methods: Study subjects were African Americans stable in maintenance-phase immunosuppression at least one year after their first cadaveric renal transplant. All patients were on triple immunosuppression consisting of low-dose prednisone, mycophenolate mofetil or azathioprine, and cyclosporine (Neoral). At study entry, cyclosporine monitoring was switched from the routine 12-hour trough levels to two-hour (C2) levels and all subsequent dose adjustments were based on the C2 level. C2 levels were measured by the fluorescence polarization immunoassay (Tdx) 2 hours after an oral dose. If the baseline level was outside the target C2 range of 800-1200 ng/ml, dose adjustments were made and serial C2 levels were obtained until the target level was reached. Follow-up C2 and serum creatinine levels were obtained every 3 months thereafter. C2 levels, cyclosporine (Neoral) dose and serum creatinine at baseline and at 6 months were tested for statistical significance (paired t test). Acute rejections were diagnosed by histological examination in cases warranted by clinical suspicion. Results: Of the 26 subjects recruited, 6 month follow-up data were available in 15 patients. A substantial number of patients were lost to follow-up due to poor compliance or other economic reasons. There were 10 males and 5 females, age 52.7 ± 5.7 years, 63.1 ± 41.9 months post-transplant. Co-morbidities at baseline included diabetes mellitus (33%), hyperlipidemia (86.6%) and hypertension (100%). Switching to C2 monitoring resulted in a decrease of cyclosporine dose in 8 patients due to high initial C2 levels (53.3%). The change in C2 level, cyclosporine dose, and serum creatinine at baseline and 6 months were as follows:FigureThere were no episodes of acute rejection. Renal function remained stable or improved in nearly all patients during the study period of 6 months. Conclusions: Cyclosporine monitoring based on two-hour levels with a target range of 800-1200 ng/ml appears safe in African American renal transplant recipients and may allow a decrease of cyclosporine dose in a substantial number of patients. Further investigation is needed to see if such dose reduction may result in reduced long-term cyclosporine toxicity.