RESUMO
BACKGROUND: Distinct effects of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers on glomerular perfusion and permselectivity are important determinants of the substances nephroprotective quality. In renal allograft recipients, however, specific effects of angiotensin antagonism on glomerular function have not been evaluated so far. METHODS: Twenty patients with favorable allograft function were included into a prospective study within the first year after renal transplantation. Glomerular filtration rate, renal plasma flow, albuminuria, and the fractional clearances of neutral dextrans were determined at baseline and after 3 months of treatment with candesartan. Ten individuals after renal donation served as controls for the baseline evaluation. RESULTS: Compared with the control group, the allograft recipients had a higher renal-vascular resistance and a lower glomerular filtration rate. Albuminuria was significantly higher; however, the difference in the dextran sieving curve was not statistically significant. Apart from mild changes in biochemical parameters, the therapy with candesartan led to a rise in serum creatinine along with a nonsignificant drop in the glomerular filtration rate. There was a highly significant drop in filtration fraction and albuminuria. Glomerular permselectivity clearly improved for a range of dextran molecular diameters from 43 Angstrom up to 73 Angstrom. CONCLUSION: A therapy with candesartan has distinct effects on glomerular function in patients after renal transplantation. A drop in filtration fraction along with an improvement in glomerular permselectivity and albuminuria point to a nephroprotective quality that should lead to a systematic clinical evaluation of candesartan even in patients with favorable renal allograft function.
