TY - JOUR
T1 - The fractional excretion of urea
T2 - a new diagnostic test for acute renal allograft rejection
AU - Corey, Howard E.
AU - Greiter, Ira
AU - Greenstein, Stuart M.
AU - Tellis, Vivian
AU - Spitzer, Adrian
PY - 1993/6
Y1 - 1993/6
N2 - Fractional excretion of fsodium (FENa) has been used in the diagnosis of acute renal allograft failure on the assumption that poor allograft perfusion should result in a low FENa. However, many patient receive medications which affect the active transport of Na+ and thus FENa. In contrast, the fractional excretion of urea (FEurea) is mostly dependent on passive forces and is therefore less influenced by drug therapy. To test the hypothesis that FEurea might be more useful than FENa in evaluating graft failure, we compared FEurea with FENa during 79 episodes of acute renal allograft dysfunction due to acute rejection (AR), cyclosporine nephrotoxicity (CsA-Nx), viral infection, or bacterial infection in 32 children and young adults with renal transplants. There was no significant difference between groups in FENa. However, FEurea was significantly lower (P<0.05) in patients with CsA-Nx (32.6±1.9%) and viral infection (32.9±3.2%) than those with AR (45.1±1.7%) or bacterial infection (38.9±2.5%). FEurea was < 35% in 20 of 28 (71.4%) episodes of CsA-Nx and 8 of 11 (72.2%) of viral infection, but only 5 of 36 (13.9%) of AR (P<0.05). FEurea was also measured during stable graft function, 7-14 days prior to allograft dysfunction. CsA-Nx was associated with a 30.5±8.3% decrease in FEurea. FEurea did not change in patients with AR. Based on these findings, we present an algorithm to aid in the differential diagnosis of acute renal allograft failure.
AB - Fractional excretion of fsodium (FENa) has been used in the diagnosis of acute renal allograft failure on the assumption that poor allograft perfusion should result in a low FENa. However, many patient receive medications which affect the active transport of Na+ and thus FENa. In contrast, the fractional excretion of urea (FEurea) is mostly dependent on passive forces and is therefore less influenced by drug therapy. To test the hypothesis that FEurea might be more useful than FENa in evaluating graft failure, we compared FEurea with FENa during 79 episodes of acute renal allograft dysfunction due to acute rejection (AR), cyclosporine nephrotoxicity (CsA-Nx), viral infection, or bacterial infection in 32 children and young adults with renal transplants. There was no significant difference between groups in FENa. However, FEurea was significantly lower (P<0.05) in patients with CsA-Nx (32.6±1.9%) and viral infection (32.9±3.2%) than those with AR (45.1±1.7%) or bacterial infection (38.9±2.5%). FEurea was < 35% in 20 of 28 (71.4%) episodes of CsA-Nx and 8 of 11 (72.2%) of viral infection, but only 5 of 36 (13.9%) of AR (P<0.05). FEurea was also measured during stable graft function, 7-14 days prior to allograft dysfunction. CsA-Nx was associated with a 30.5±8.3% decrease in FEurea. FEurea did not change in patients with AR. Based on these findings, we present an algorithm to aid in the differential diagnosis of acute renal allograft failure.
KW - Fractional excretion
KW - Rejection
KW - Transplantation
KW - Urea
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U2 - 10.1007/BF00853217
DO - 10.1007/BF00853217
M3 - Article
C2 - 8518096
AN - SCOPUS:0027312655
SN - 0931-041X
VL - 7
SP - 268
EP - 272
JO - Pediatric Nephrology
JF - Pediatric Nephrology
IS - 3
ER -