Abstract
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.
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References
Espinel CH (1976) The FENa test: use in the differential diagnosis of acute renal failure. JAMA 236: 579–581
Hong CD, Kappor BS, First MR, Pollack VE, Alexander JW (1979) Fractional excretion of sodium after renal transplantation. Kidney Int 16: 167–178
Shabtai M, Anaise D, Miller F, Oster ZH, Atkins H, Waltzer WC, Yland MJ, Rapaport FT (1989) The predictive value of renal cortical perfusion indices during acute allograft rejection crisis. Transplant Proc 21: 1881–1900
Chan MK, Wong KK, Cheng KP, Li MK (1988) Clinical prevalence and significance of electrolyte disorders in cyclosporine A-treated patients. Transplant Proc 20: 705–708
Dieperink H, Leyssac PP, Kemp E, Starklint H, Frandsen NE, Tvende N, Moller J, Buchler Frederiksen P, Rossing N (1987) Nephrotoxicity of cyclosporin A in humans: effects on glomerular filtration and tubular reabsorption rates. Eur J Clin Invest 17: 493–496
Morales JM, Andres A, Prieto C, Ruilope LM, Alcazar A, Oliet A, Praga M, Rodicio JL (1987) Fractional excretion of sodium represents an index of cyclosporine nephrotoxicity in the early post-transplant period. Transplant Proc 19: 4005–4007
Morales JM, Andres A, Alcazar JM, Prieto I, de Tueste D, Ruilope LM, Rodicio JL (1988) Usefulness of the fractional excretion of sodium as index of cyclosporine nephrotoxicity in renal transplantation. Transplant Proc 20: 691–699
Shah BV, Hong CD, First MR (1990) Effect of cyclosporine on fractional excretion of sodium in renal transplant patients. Clin Transplant 4: 102–107
Tonnesen AS, Hammer RW, Weinmann EJ (1983) Cyclosporine and sodium and potassium excretion in the rat. Transplant Proc 15: 2730–2735
Kaplan AA, Kohn OF (1990) The fractional excretion of urea to evaluate renal, dysfunction (abstract). J Am Soc Nephrol 1: 335
Hanley JA, McNeil BJ (1982) Meaning and use of the area under a receiver operating characteristic (ROC) curve. Radiology 143: 29–36
Kudo LH, Van Baak AA, Rocha AS (1990) Effect of furosemide on water and urea transport in cortical and inner medullary collecting duct. Kidney Int 37: 1248–1255
Armsen T, Reinhart HW (1991) Transtubular movement of urea at different degrees of water diuresis. Pflugers Arch 326: 270–280
Larson TS, Jamison RL (1989) Renal excretion of urea. In: Massry SG, Glassock RJ (eds) Textbook of nephrology. Williams and Wilkins, Baltimore, pp. 85–87
Morgan T, Berliner RW (1968) The permeability of the loop of Henle, vasa recta, and collecting duct to water, urea, and sodium. Am J Physiol 215: 108–115
Stephenson JL (1972) Concentration of urine in a central core model of the renal counterflow system. Kidney Int 2: 85–94
Sands JM, Nonoguchi H, Knepper MA (1987) Vasopressin effects urea and H2O transport in inner medulalary collecting duct segments. Am J Physiol 253: F823-F832
Curtis JJ, Luke RG, Dubovsky E, Diethelm AG, Whelchel JD, Jones P (1986) Cyclosporin-A in therapeutic doses increases renal allograft vascular resistance. Lancet II: 477–479
Curtis JJ, Laskow DA (1988) Cyclosporine-induced nephrotoxicity: pathophysiology of reduced blood flow. Transplant Proc 20: 540–543
Kaskel FJ, Devarajan R, Arbeit LA, Partin JS, Moore LC (1987) Cyclosporine nephrotoxicity: sodium excretion, autoregulation and angiotensin II. Am J Physiol 252: F733-F742
Kaskel FJ, Devarajan P, Arbeit LA, Moore LC (1988) Effects of cyclosporine on renal hemodynamics and autoregulation in rats. Transplant Proc 20: 603–609
Murray BM, Paller MS, Ferris TF (1985) Effect of cyclosporine administration on renal hemodynamics in conscious rat. Kidney Int 28: 767–774
Sabatini M, De Nicola, Uccello F, Russo D, Conte G, Dal Canton A, Andreucci VE (1990) Absence of acute nephrotoxicity with low doses of cyclosporin: experimental study in the rat. Nephrol Dial Transplant 5: 69–74
Barros EJG, Boim MA, Ajzen H, Ramos OL, Schor N (1987) Glomerular hemodynamics and hormonal participation on cyclosporine nephrotoxicity. Kidney Int 32: 19–25
Whelchel JD, Delaney VB, O'Brian D, Ling B, Fekete P (1988) Efficacy and cost of the various test used in the diagnosis of rejection in cadaveric renal transplant recipients (abstract). Kidney Int 35: 526
Winchester JF, Gelfand MC, Foegh ML, Helfrich GB, Schreiner GE (1983) Early indicators of renal allograft rejection. Kidney Int 24: S34-S40
Gray W, Derek R, Richardson A, Hughes D, Fuggle S, Dunhill M, Higgins R, McWhinnie D, Morris PJ (1992) A prospective randomized, blind comparison of three biopsy technique in the management of patients after renal transplantation. Transplantation 566: 1126–1232
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Corey, H.E., Greiter, I., Greenstein, S.M. et al. The fractional excretion of urea: a new diagnostic test for acute renal allograft rejection. Pediatr Nephrol 7, 268–272 (1993). https://doi.org/10.1007/BF00853217
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DOI: https://doi.org/10.1007/BF00853217