Serum level of Cyclosporine (CsA), as the main immunosuppressant in kidney transplantation, is being measured by Cyclosporine through (C0) and 2-hours post-dose (C2) concentrations. C2, compared to C0, has a better correlation with are area under curve (AUC) of the CsA and acute graft rejection. However, it is not clear that which of these measures is correlated with the long term graft outcome. We evaluated the relationship of C0 and C2 with graft survival in an Iranian group of kidney transplanted patients.
Method: In a case-control design, we selected 215 adult kidney recipients. Inclusion criteria was at least 2 years of follow up after kidney transplantation, and Cr<1.5 at the first 6 months post transplantation. From these, 198 have functioning graft (Group I) and 17 had graft failure (Group II). The serum C0 and C2 levels for the first 6 months post transplantation were extracted. We compared the mean of these measures in Groups I and II. The mean (SD) C0 and C2 in Group I, were 248.5±104.5 and 886.3±266.9 (ng/ml), respectively. The same measures were 257.9±126.5 and 712.8±273.2 (ng/ml), in Group II, respectively. Patients in Group I had significantly higher C2 levels than that of Group II(p=0.01), but no significant difference was detected in C0 levels between the two groups (p>0.05). We found that the C2, but not C0, in the early 6 months post-transplantation can be considered as a predictor of long-term graft survival. The findings here support the results of other studies that suggest cyclosporine concetration monitoring by C2 measurement.