Aliskiren reduces albuminuria after kidney transplantation

Background: The renoprotective effects of the direct renin inhibitor, aliskiren, in renal transplant recipients have been supposed, but not finally proven. We performed an exploratory double-blind, losartan controlled, cross-over study to evaluate the influence of aliskiren, direct renin inhibitor, on albuminuria and other surrogate markers of kidney injury in patients after renal transplantation. The safety of this therapy was also evaluated. Method: 16 of 18 patients (12 M, 4 F), 48.3 +/- 9.0 years, 57.7 +/- 9.1 months after kidney transplantation, with hypertension and stable serum creatinine 1.4 +/- 0.08 mg/dl without proteinuria, completed the protocol. Each patient underwent two 8-week treatment periods (one with 150 mg of aliskiren, and one with 50 mg of losartan) in random order, allowing an 8-week placebo washout between them. Results: There were no differences in albuminuria, transforming growth factor beta-1 and 15-F2t-isoprostanes urine excretion between aliskiren and losartan. Creatinine serum level, eGFR, 24 h systolic and 24 h diastolic blood pressure were stable through the study. There were no differences in haemoglobin and potassium serum concentration between studied drugs. Conclusion: Aliskiren decreases albuminuria in renal transplant recipients with clinically minimal side effects. The effect does not differ from that of losartan.