RENAL FUNCTIONAL RESERVE IN CHILDREN WITH HISTORY OF HEMOLYTIC-UREMIC SYNDROME AND IN CHILDREN WITH SOLITARY KIDNEYS

Abstract

Renal Functional Reserve(RFR) is the capacity of the kidney to increase the rate of filtration under certain demands, e.g., an oral protein load. The absence of RFR may be the equivalent of glomerular hyperfiltration, since it suggests that the available nephrons are working at their maximal level. The purpose of this study was to determine the RFR in 17 normotensive patients with history of Hemolitic-Uremic Syndrcme(HUS) and normal CrCl, comparing them to 10 normotensive patients with Solitary Kidneys(SK) and normal CrCl. and to 15 normal children. We measured the RFR in response to an oral protein load (45g/m2). All normal children increased their CrCl significantly (x 170.9±36.06 mt/min/1-73m2 vs. 131.3±28.74ml/min/1.73m2, p<0.0001). Only 6/17 patients with history of HUS had a response comparable to the normal group, whereas 8/17 did not change their CrCl and 3/17 had a “paradoxical response”, i.e. they decreased their CrCl by 25 - 40%. In the SK group 3/10 patients had a normal response, while 6/10 patients had a paradoxical response and 1/10 did not change his CrCl.