Graft ischemia correlates with urinary excretion of the proximal marker enzyme fructose-1,6-bisphosphatase in human kidney transplantation.
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.
Kotanko
P
P
Department of Internal Medicine, Krankenhaus Barmherzige Brüder (Marschallgasse) Graz. kotanko1@ping.at
Margreiter
R
R
Pfaller
W
W
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*
D015415:Biomarkers; D006597:Fructose-Bisphosphatase