Abstract: Ｏｂｊｅｃｔｉｖｅ：To observe the longterm effects and prognosis of conversion from calcineurin inhibitors (CNIs) to sirolimus in biopsyproven low immunological risk renal transplant recipients (RTRs).
Ｍｅｔｈｏｄｏｌｏｇｙ：The longterm efficacy of conversion from CNIs to sirolimus in low immunological risk RTRs with no signs of acute or chronic graft rejection proved by biopsy was retrospectively analyzed.We collected the clinical and histological data, observing laboratory results, graft function, allograft survival and adverse events after conversion during follow up.
Ｒｅｓｕｌｔｓ：This study enrolled 38 patients,including 12 cases received protocol biopsy and 26 cases were performed with indication biopsy due to increased serum creatinine (SCr). Mean duration of sirolimus therapy was 8071±4137 months(range:12~194 months). SCr steadily declined after conversion. In indication biopsy group, the median SCr (15647 μmol／L proconversion) decreased significantly 2 years later (P<0001) and reduced to 12376 μmol／L at last followup. In protocol biopsy group, the median SCr was 12730 μmol／L proconversion, SCr remained stable for a long time and decreased to a median of 11138 μmol／L 4 years later (P<0001).Only 2 cases lost the graft which may result from the higher SCr level before conversion.Platelet count, serum lipid increased and serum albumin, total protein decreased after conversion, but most within normal range. New onset hypertriglyceridemia (n=8) and hypercholesterolemia (n=13), de novo PRA (n=7), new rejection (n=2), pulmonary infection (n=5), new onset proteinuria (n=18) were observed in the longterm followup period. Repeated biopsies showed no significant signs of rejection in 5 cases.Analysis showed RTRs with positive proteinuria before conversion had shorter duration of taking sirolimus(P=0004).High SCr levels (>1768 μmol／L) linked to poor prognosis (P=0046).
Ｃｏｎｃｌｕｓｉｏｎ：Conversion from CNIs to Sirolimus based on biopsy is safe and effective for renal allografts in low immunerisk recipients, most of them can benefit from improved GFR and longterm allograft survival after conversion. Even the low immunological risk RTRs received protocol biopsy can also benefit from this conversion.