Skin-autofluorescence is an independent predictor of graft loss in renal transplant recipients.
BACKGROUND
Skin-autofluorescence (skin-AF) noninvasively measures the tissue accumulation of advanced glycation end products (AGEs). AGEs are nephrotoxic and potential effectors of cardiovascular mortality. We investigated whether skin-AF predicted graft loss after kidney transplantation.


METHODS
A total of 302 renal transplant recipients were enrolled at a median time of 6.1 (2.6-12.1) years after transplantation and were subsequently followed up for first occurrence of graft loss (i.e., graft failure or all-cause mortality) for 5.2 (4.6-5.4) years. The association of baseline skin-AF with graft loss was investigated with univariable and multivariable Cox-regression and receiver-operator-characteristic curve analyses.


RESULTS
Baseline skin-AF was 2.7+/-0.8 arbitrary units. Skin-AF predicted graft loss in a univariable Cox regression analysis (Hazard ratios 2.40 [1.75-3.29], P<0.001) and in a multivariable model (Hazard ratios 1.83 [1.22-2.75], P=0.003), adjusted for other identified risk-factors, including patient age, creatinine clearance, protein excretion, high sensitivity C-reactive protein (hsCRP), and human leukocyte antigen-DR mismatching. The area under the receiver-operator-characteristic curve for skin-AF as predictor of graft loss was significantly different from 0.5. Skin-AF was also a significant predictor of graft failure and mortality as separate end points.


CONCLUSIONS
We conclude that skin-AF is an independent predictor of graft loss in kidney transplant recipients. Although skin-AF is not a direct measurement for AGEs, we believe that our results do support the hypothesis that accumulation of AGEs in renal transplant recipients contributes to the development of graft loss.
Department of Internal Medicine, University Medical Center Groningen and University of Groningen, Groningen, The Netherlands.
Jasper W L
JW
Hartog
Sascha
S
Gross
Leendert H
LH
Oterdoom
Rutger M
RM
van Ree
Aiko P J
AP
de Vries
Andries J
AJ
Smit
Jan P
JP
Schouten
Peter P
PP
Nawroth
Reinold O B
RO
Gans
Willem J
WJ
van Son
Angelika
A
Bierhaus
Stephan J L
SJ
Bakker
D000328:Adult; D000368:Aged; D005260:Female; D005453:Fluorescence; D006085:Graft Survival; D006801:Humans; D007676:Kidney Failure, Chronic / Q000601:surgery*; D016030:Kidney Transplantation / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009426:Netherlands; D011237:Predictive Value of Tests; D012044:Regression Analysis; D012189:Retrospective Studies; D012867:Skin / Q000473:pathology*; D016019:Survival Analysis; D014019:Tissue Donors / Q000706:statistics & numerical data; D017211:Treatment Failure