Evolution of single kidney glomerular filtration rate in urinary tract infection

The aim of this study was to evaluate renal function during the acute phase of symptomatic urinary tract infection and the changes observed several mo nths later. Overall glomerular filtration rate (GFR) as well as single kidn ey GFR (SKGFR) were calculated using the combination of a left/right uptake ratio obtained from technetium 99m-dimercaptosuccinic acid (DMSA) scintigr aphy and (51)chromium-EDTA plasma clearance. Forty-four patients with obvio us unilateral or bilateral DMSA abnormalities were studied. In patients wit h unilateral lesions, both the overall GFR and the SKGFR were significantly higher during the acute phase of infection than several months later, on t he abnormal side as well as the normal side. The relative percentage uptake was lower on the abnormal side than the normal side, obviously due to loss of functional parenchyma. This percentage increased significantly during t he recovery phase, reflecting the total or partial healing of the renal les ions, despite the decrease of the corresponding SKGFR. However, during both the acute and the recovery phase, the relative percentage uptake of the ab normal kidney was in the normal range and often close to 50%. In patients w ith bilateral lesions, no significant changes were observed between the acu te phase and the recovery phase.