Correlation Between Cyclosporine Trough Levels and 2-Hour Postdose Blood Levels and Target C2 Levels in Patients after 12 Months Post Kidney Transplantation

Kim, Jung Mi; Kim, Dong Han; Kim, Tae Woo; Cho, Kyu Hyang; Choi, Jun Hyuk; Park, Jong Won; Do, Jun Young; Yoon, Kyung Woo

Abstract

BACKGROUND: Cyclosporine dosing is traditionally based on trough levels(C0 level) rather than area under the concentration-time curve(AUC), although AUC correlates better with post transplantation acute rejection and acute toxicity. It is reported that C2 levels(2-hour postdose blood levels) are single sampling point that best reflects AUC0-4. But there has been no recommended C2 levels for patients after 12 months post kidney transplantation. The purpose of this study was to evaluate the correlation between C0 levels and C2 levels and define recommended target C2 levels in patients after 12 months post kidney transplantation.
METHODS
Seventy three patients after 12 months post transplantation were studied. 83 data were obtained from 73 renal transplant patients. Blood C0 levels, blood C2 levels, body weight and serum creatinine level were measured. Blood cyclsporine levels were measured by monoclonal fluorescence polarization immunoassay(mFPIA)(TDX, Abbot). The data of C0 levels were divided into three groups : low group (mean+SD, 197.1 ng/mL).
RESULTS
There was a positive correlation between C0 levels and C2 levels, but no correlation between C0 levels and C2 levels when C0 levels were divided into three groups. There was a positive correlation between cyclosporine/body weight and C2 levels in normal C0 group. Recommended C2 levels in normal C0 group is 724.7+/-210.1 ng/mL.
CONCLUSION
It is assumed that cyclosporine doses can be individualized by using C2 levels rather than C0 levels in renal transplant patients. However, prospective study may be needed to confirm the improvement of longterm renal allograft survival by individualizing cyclosporine doses based on C2 levels.