Histopathological findings in renal allografts at time of transplantation and correlation with onset of graft function.

Histopathological changes quantified using the chronic allograft damage index (CADI) have been shown to predict subsequent graft outcome and developing chronic rejection. The aim of the study reported here was to investigate the extent to which cadaveric renal allografts exhibit histopathological changes at time of transplantation, focusing on changes covered by the CADI. We also analysed whether any histopathological change predicts delayed graft function. One hundred and twenty-eight cadaveric kidney allografts with adequate protocol biopsy were studied. Tubular epithelial anisometric vacuolization was the commonest change, found in 62% of grafts and scored moderate or severe in 28% of these cases. Other prevalent changes were interstitial fibrosis, vascular hyalinosis, glomerular sclerosis and tubular basement-membrane thickening in 40%, 37%, 28% and 22% of biopsies, respectively. Intensities were, however, scored as mild in over 95% of specimens. The mean CADI for all grafts was 0.74. A significant difference in CADIs was seen between grafts from donors under and over 40 years of age. Grafts with early, delayed and no function had a similar incidence of histopathological changes. Histopathological changes in renal allografts were mostly uncommon and mild at time of transplantation, but some grafts exhibited changes which were quantified using the CADI. Though histopathological changes quantified with the CADI are predictive of subsequent graft function, they did not affect onset of graft function.