H-13: pathology in renal transplant
H-15: Late rejection
The Predictive Value of Kidney Allograft Baseline Biopsies for LongTerm Graft Survival
Katrien De Vusser* † , Evelyne Lerut‡§ , Dirk Kuypers* † , Yves Vanrenterghem* † , Ina
Jochmans‖¶ , Diethard Monbaliu‖¶ , Jacques Pirenne‖¶ and Maarten Naesens* †
JASN November 2013 vol. 24 no. 11: 1913-1923
Correspondence: Dr. Maarten Naesens, Nephrology and Renal Transplantation, University
Hospitals
Leuven,
Herestraat
49,
3000
Leuven,
Belgium.
Email:
maarten.naesens@uzleuven.be
ABSTRACT
The effect of baseline histology and individual histologic lesions at the time of transplantation on
long-term graft survival has been evaluated using different scoring systems, but the predictive
capacity of these systems has not been adequately validated. All kidney recipients transplanted
in a single institution between 1991 and 2009 who underwent a baseline kidney allograft biopsy
at transplantation were included in this prospective study (N=548). All baseline biopsies were
rescored according to the updated Banff classification, and the relationship between the
individual histologic lesions and donor demographics was assessed using hierarchical
clustering and principal component analysis. Survival analysis was performed using Cox
proportional hazards analysis and log-rank testing. Mean follow-up time was 6.7 years after
transplantation. Interstitial fibrosis, tubular atrophy, and glomerulosclerosis associated
significantly with death-censored graft survival, whereas arteriolar hyalinosis and vascular
intimal thickening did not. Notably, donor age correlated significantly with interstitial fibrosis,
tubular atrophy, and glomerulosclerosis and associated independently with graft survival. On
the basis of these findings, a novel scoring system for prediction of 5-year graft survival was
constructed by logistic regression analysis. Although the predictive performance of previously
published histologic scoring systems was insufficient to guide kidney allocation in our cohort
(receiver operating characteristic area under the curve ≤0.62 for each system), the new system
based on histologic data and donor age was satisfactory for prediction of allograft loss (receiver
operating characteristic area under the curve = 0.81) and may be valuable in the assessment of
kidney quality before transplantation.
COMMENTS
The demand for kidney grafts exceeds the supply of available organs. As a result, there is an
increasing use of older and extended criteria donor kidneys. This is not without consequences.
The risk of graft failure after an extended criteria donor kidney transplant is 70% higher than
after transplantation with a standard criteria donor. The intrinsic quality of the kidney at
transplantation becomes increasingly important for the post-transplant histologic evolution and
long-term graft survival The Predictive Value of Kidney Allograft Baseline Biopsies for LongTerm Graft Survival
Univariate and multivariate Cox proportional hazards analysis of death-censored graft survival
based on baseline histology and donor demographic variables (n=542)
Variables
Univariate Analysis
Multivariate Analysis
Hazard
Ratio(95% P
Confidence Interval)
Hazard
Ratio(95% P
Confidence Interval)
1.72 (1.2 до 2.46)
0.003
1.90 (1.24 до 2.9)
0.003
Stroke as reason of donor 1.38 (0.83 до 2.29)
death
0.60
–
–
Donor history of hypertension
1.18 (0.61 до 2.29)
0.62
–
–
Donor diabetes mellitus
1.69 (0.23 до 12.2)
0.60
–
–
Donor history of smoking
0.90 (0.49 до 1.69)
0.75
–
–
(present 1.60 (0.99 до 2.58)
0.05
0.98 (0.59 до 1.76)
0.90
0.40
–
–
Donor demographics
Donor age ( 60 yr)
Baseline biopsy histology
Tubular
atrophy
versus absent)
Arteriolar hyalinosis (present 1.230 (0.71 до 2.38)
versus absent)
Interstitial fibrosis
versus absent)
(present 1.85 (1.32 до 2.57)
0.0003 1.51 (1.02 до 2.26)
0.03
Vascular intimal thickening 1.08 (0.26 до 4.43)
(present versus absent)
0.92
–
–
Glomerulosclerosis
versus <10%)
0.01
1.32 (0.73 до 2.39)
0.35
(≥10% 1.98 (1.21 до 3.26)
De Vusser and colleagues propose a novel scoring system, the Leuven Donor Risk Score that
predicts 5-year graft survival with 81% sensitivity and 85% specificity.3 The proposed score is a
sum score based on known histologic (glomerulosclerosis, interstitial fibrosis, tubular atrophy)
and demographic (donor age) characteristics that are, as noted above, individually associated
to varying degrees with graft survival. The strengths of De Vusser and colleagues’ study include
a large cohort of patients, long-term follow-up data, in-depth statistical analyses, and
comparative evaluation of historical, previously published alternative scoring systems.
Although these data are intriguing, the Leuven Donor Risk Score they propose is so far the
most accurate predictive model. It is important to note that they have certain limitations, some of
which are outlined by the authors themselves. The analysis is based on single center central
European observations accounting for region-specific demographic characteristics. The authors
report excellent graft survival, 94% at 2 years and 90% at 5 year.