Biopsy of marginal donor kidneys: Correlation of histologic findings with graft dysfunction

Background. Kidney biopsies are being used to evaluate marginal donors, but rigorous statistical validation of this practice with multivariate analysi s has not been performed. Methods. To analyze histologic parameters in 78 donor biopsies for their ab ility to predict graft dysfunction, we used a proportional odds model that included both donor and recipient factors. Glomerulosclerosis was categoriz ed into grades 0, 1, 2, and 3, corresponding to 0, 1-10%, 11-20%, and 21-30 % global sclerosis, respectively. The degrees of interstitial fibrosis, tub ular atrophy, arteriosclerosis, and arteriolar hyalinosis were graded from 0 to 3+, using definitions suggested by the Banff Schema of allograft patho logy. Results. Increasing donor age was associated with higher glomerulosclerosis , tubular atrophy, and arteriosclerosis. Kidneys with any degree of interst itial fibrosis were 2.6 times [odds ratio (OR)] more likely to experience a worse outcome at 6 months (P=0.02). This association held up after correct ion for acute rejection (OR 2.5, P=0.03) and high panel-reactive antibody ( OR 3.4, P=0.006). However, the OR was reduced to 1.9 (P=0.15) after control ling for recipient age. With each increment in the grade of glomerulosclero sis, the odds for a worse outcome at 12 months increased to 2.3 (P=0.005). The value for OR became 2.0 (P=0.03) when controlling for recipient age (P= 0.01), 2.4 (P=0.005), when controlling for acute rejection, and 2.3 (P=0.00 6) when controlling for high panel-reactive antibody. Conclusions. Histopathological parameters present in donor biopsies can ind ependently predict posttransplant graft function. Implications for the pool of donor organs available for transplantation are discussed.