Satisfactory outcome despite low 2-hour postdose cyclosporine level in Iranian kidney recipients

Cyclosporine has a narrow therapeutic serum level in kidney transplantation. Achieving the recommended therapeutic levels is necessary, but in different ethnic groups, the impact of the cyclosporine level on patient and graft survival has not been fully addressed yet. We investigated this issue by studying the 2-hour postdose serum concentration of cyclosporine (C2) and the long-term graft and patient survival in Iranian transplant recipients. A total of 397 kidney recipients were evaluated for the C2 serum levels. All patients were under treatment with prednisolone, mycophenolate mofetil, and cyclosporine (Neoral). Measurements C2 were considered at different time intervals: the first 2 months, 2 to 6 months, and after 6 months posttransplantation. The mean of C2 levels at specified intervals were evaluated and compared with the recommended optimal ranges. Patient and graft survival rate were also calculated. In the studied patients, C2 levels were lower than the upper recommended range in 96.9%, 83.6% and 64.5% in the first 2 months, between 2 and 6 months, and after 6 months posttransplantation, respectively. The overall 5-year patient and graft survival rates were 95% and 85%, respectively. Despite the fact that the majority of the patients had C2 levels lower than the recommended values, we observed good patient and graft survival rates. Our data suggests that different populations may need different target levels definition.