Effect of valsartan on urinary protein excretion and renal function in patients with chronic renal allograft nephropathy☆

Abstract 

Chronic allograft nephropathy (CAN) remains a significant cause of late renal allograft loss. Although many factors may be involved in pathogenesis, the hemodynamic and fibrogenic consequences of long-term therapy with cyclosporine (CsA) have been implicated as important potentially reversible causes. CsA's effect on CAN is mediated in part through increased renal expression of TGF-β, which can be modified by administration of angiotensin receptor blockers (ARBs). A pilot study was undertaken to evaluate the safety and efficacy of the ARB valsartan on renal function and proteinuira in patients with CAN. Ten patients on CsA-based therapy with evidence of CAN received valsartan in an initial dose of 80 mg/d, force titrated to 160 mg/d after 4 weeks, for a total of 52 weeks. Renal function was evaluated by serum creatinine, 24-hour creatinine clearance (CrCl), and isotope, GFR and urinary protein by 24-hour protein excretion. The 10 patients were aged 20 to 71 years and had been transplanted for 88.2 ± 64.8 months at the time of study. After 52 weeks of valsartan therapy mean blood pressure (BP) fell from 152/88 mm Hg to 138/77 mm Hg (P = .06); serum creatinine rose from 206 ± 55 μmol/L to 238 ± 81 μmol/L (P = .22.); GFR fell from 39.8 ± 17.6 to 31.9 ± 19 mL/min (P = .23); and urine protein fell from 2.16 ± 2.7 to 1.12 ± .095 g/24 hours (P = .13). Side effects of valsartan therapy were few and included transient hyperkalemia in 2/10 patients. The small rise in serum creatinine and fall in GFR observed were not statistically significant. Urine protein fell by more than 50%, though the small patient numbers in this pilot study prevent this from achieving statistical significance. It is concluded that valasartan reduces BP and proteinuria in CAN patients without inducing a serious worsening in renal function. Valsartan may have a role to play in the management of patients with CAN.