change of cyclosporine absorption over the time after kidney transplantation

background although the immunosuppressant cyclosporine (csa) is widely used after kidney transplantation over the long term, there is still no firm consensus on the best way to monitor of csa blood levels. objectives cyclosporine (csa) assay is critical for the management of renal transplant recipients due to inter– and intra–patient variation in csa absorption and metabolism. patients and methods: in a retrospective cross sectional study, blood levels of csa (through and 2 hours post dose) measured at least 5 times during 3 years post transplantation, in 7702 kidney transplant recipients from different transplant center of tehran, ir iran between 2008 and 2012. cyclosporine absorption (ca) calculated c2/c0 ratio. results ca had a significant correlation with allograft function (p = 0.000, r =.0.285), this correlation was stronger than its relationship with c0 and c2 blood levels (p = 0.000 and p = 0.000 as well as r = 0.033 and r = 0.090, respectively). in univariate analysis during different times after transplantation, c0 and c2 blood levels significantly decreased over three years follow up (p = 0.000), (p = 0.000); while, ca reversely increases over the time (p = 0.000). in linear regression model overall ca levels had correlation with lower age of recipient (p = 0.02), hypokalemia (p = 0.001), higher level of creatinine (p = 0.02) and triglyceride (p = 0.001). conclusions the present study shows that csa absorption changes trough the post-transplant time and appears to increases over time in long–term period after kidney transplantation.