Sirolimus conversion experience in a single center

One major cause of graft loss is chronic allograft nephropathy (CAN), which may relate to calcineurin inhibitors (CNIs). We converted CAN cases from CNIs to sirolimus and observed the outcomes.

From January 2004 to August 2007, there were 28 kidney recipients in our center with creeping creatinine levels compatible with CAN. We started sirolimus at 2 mg/d and reduced the CNIs gradually. Sirolimus trough levels were kept between 5 and 8 ng/mL. Mycophenolic acid was cut in half; there was no adjustment on prednisolone dose.

The mean switch time was 47.3 months after transplantation. One case discontinued sirolimus due to severe drug-induced pneumonitis. Twelve of the 27 (45%) patients showed improvements in graft function. The most frequent complications were anemia (13/28), hyperlipidemia (13/28), and pneumonitis (4/28). A baseline serum creatinine level less than 2.2 mg/dL seemed to forecast a response to sirolimus conversion. Most of the graft functional improvement occurred within 6 months after the switch. No graft or patient loss was encountered.

Our experience suggested that 45% of patients with sirolimus conversion showed improved graft function. Among patients within 1 year after transplantation, those with a creatinine level less than 2.2 mg/dL, no proteinuria, and no hyperlipidemia seemed to be better candidates for Sirolimus conversion.