title: Graft ischemia correlates with urinary excretion of the proximal marker enzyme fructose-1,6-bisphosphatase in human kidney transplantation.
abstract: This study was undertaken to test the hypothesis that ischemia prior to transplantation causes tubular damage without clinical evidence of graft dysfunction. The urinary excretion of fructose-1,6-bisphosphatase (EC 3.1.3.11, FBPase), a cytosolic enzyme located exclusively in the proximal tubules, and the lysosomal enzyme N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30) were measured daily between postoperative days 1 and 4 in 25 renal cadaveric graft recipients who enjoyed an entirely uncomplicated first postoperative month. During the first 4 posttransplant days urinary FBPase excretion was 0.9 +/- 0.5 U/g (0.1 +/- 0.06 U/mmol) urinary creatinine [+/-SD; range 0.2-2.1 U/g (0.02-0.24 U/mmol)]. Cold ischemia time was 20.6 +/- 8.4 h (median 22 h, range: 3-32 h). Multiple regression revealed a significant correlation between cold ischemia time and posttransplant urinary FBPase excretion (multiple R = 0.65, p < 0.001). There were no confounding effects of recipient's age and gender, number of previous transplants, cyclosporin A levels, warm ischemia time, anastomosis time, donor age and gender. Urinary FBPase excretion was significantly lower in grafts stored for a shorter time than the median cold ischemia time of 22 hours (0.69 +/- 0.42 U/g, n = 13) as compared to those stored for a longer period of time (1.13 +/- 0.56 U/g; n = 12; p = 0.035). These results indicate that graft injuries occur even in the absence of graft dysfunction and that the duration of cold ischemia itself correlates with a degree of tubular cell damage as defined by urinary FBPase excretion.
authors.affiliation: Department of Internal Medicine, Krankenhaus Barmherzige Brüder (Marschallgasse) Graz. kotanko1@ping.at
authors.forename: P
authors.initials: P
authors.lastname: Kotanko
authors.forename: R
authors.initials: R
authors.lastname: Margreiter
authors.forename: W
authors.initials: W
authors.lastname: Pfaller
mesh_terms: D000328:Adult; D015415:Biomarkers; D002940:Circadian Rhythm / Q000502:physiology; D005260:Female; D006597:Fructose-Bisphosphatase / Q000652:urine*; D006801:Humans; D007511:Ischemia / Q000201:enzymology / Q000652:urine; D016030:Kidney Transplantation / Q000502:physiology*; D008297:Male; D015999:Multivariate Analysis; D012079:Renal Circulation / Q000502:physiology*
chemical_list: D015415:Biomarkers; D006597:Fructose-Bisphosphatase