To analyze the correlation between allograft zero-time biopsy results and kidney transplant recipients with delayed graft function (DGF) after transplantation.

The clinical data of kidney transplant recipients and donors in the Institute of Kidney Transplantation, the First Affiliated Hospital, Medical College of Xi′an Jiaotong University from May 2018 to April 2019 were retrospectively analysed, all the donors were donation after cardiac death (DCD). Zero-time biopsy was used to assess the quality of donor kidneys. Banff 2013 criteria, Remuzzi score and Maryland aggregate pathology index (MAPI) were used to assess the pathology grades and scores in the pre-transplant biopsy. Eligible samples were defined as >7 glomerulus and >2 arterioles. According to the occurrence of DGF, the kidney transplant recipients were divided into DGF group and non-DGF group. Mann-Whitney U test was used to compare glomerulus sclerosis rate, arteriole hyalinosis rate, Banff 2013 criteria scores, Remuzzi scores and MAPI scores between the 2 groups. Chi-square test was utilized to compare renal interstitial fibrosis, tubular atrophy, thickening of the arteriole wall, hyaline degeneration of arteriole, renal tubule injury/necrosis and microthrombus in glomerulus between the 2 groups. Logistic regression model was used to analyze the correlation between allograft zero-time biopsy results and DGF of transplant kidney.

133 recipients were enrolled in this study, 26(19.5%) recipients developed DGF (DGF group). There were 107 recipients in non-DGF group. Among the eligible samples of donor kidneys, the average amount of glomeruli were (13±5), the median glomerulus sclerosis rate was 5.8%(0-13.3%), the median amount of arterioles were 5(3-6), the median hyaline degeneration rate of arteriole was 0(0-11%), 47.4%(63/133) of the kidneys had interstitial fibrosis, 48.1%(64/133) of the kidneys had tubular atrophy, 58.6%(78/133) of the kidneys had arterial intimal fibrosis thickening, 36.8%(49/133) of the kidneys had hyaline degeneration in the arterial wall, none of the kidneys had glomerular micro thrombosis, all kidneys had various renal tubule injury/necrosis. The renal interstitial fibrosis, tubular atrophy, renal tubule injury/necrosis and Remuzzi scores between the 2 groups had significant difference (χ²=7.65, 7.92 and 16.81, Z=-2.02, all P<0.05). Multivariate logistic regression model shown that renal tubule injury/necrosis was an independent risk factor of DGF in kidney transplant recipients.

Pre-implantation pathological assessment provide some guidance in predicting short-term transplantation outcome. We should try to avoid the factors that induce renal tubule injury/necrosis in the procedure of donor maintenance and organ harvesting for decreasing the occurrence risk of DGF.