Prospective Study On The Value And Significance Of Time-Zero Biopsy In Evaluation Of Donor Kidney Quality

Objective:To observe the histopathology of the donor kidney and assess its potential high-risk factor;to evaluate the impact of renal histological abnormalities detected at Time-Zero Biopsy on renal function including the donor kidney GFR and the short-term graft eGFR;to explore the value and significance of Time-Zero Biopsy in valuation of donor kidney quality.Methods:36 cases of patients underwent kidney transplant,including 16 living donor kidney transplants and 20 cadaveric kidney transplants,from July 2008 to February 2009 in our center were enrolled.Pre-operation biochemical data and clinical information were collected.Kidney biopsy was done after organ procurement and reperfusion with a 16-gauge biopsy needle(Tru-Cut) in an automate gun at the lower pole to obtain two tissue specimens,one of which fixed with 10%Formaldehyde immediately and then Paraffin-embedded,stained with hematoxylin-eosin stain and polyclonal anti-CD133 antibody(Masson stain and PAS stain used when necessary) and the other kept in -70℃Liquid nitrogen to establish specimens treasury.According to Remuzzi' scoring system,the severity of the renal histological abnormalities was classified and necessary interventions were given to the patients with a poor-quality kidney as assessment.All the cases were followed up post-operation routinely and allograft biopsy was done on the recipients with fluctuations in serum creatinine.The diagnosis of the allograft diseases were based on the findings at Time-Zero Biopsy.All the data were analyzed and evaluated by SPSS 17.0 and P value of less than 0.05 was considered significant.Results:1.No biopsy-related complications occurred.2.61.1%of donor kidney biopsies(22 cases) were found varying degrees of histological changes,containing 13 cases minor changes and 9 cases moderate to severe changes.The main histo-pathological change in individual morphologies were glomerulosclerosis,tubular type and renal interstitial inflammatory cell infiltration,the incidence of which were 19.4%,19.4%and 16.7%,respectively.3.The incidence of histological changes was significantly higher in kidney biopsies with donors' age more than 50 (χ~2=4.862,p=0.027),but it did not seem higher in cadaveric kidneys with prolonged cold ischemia time than living donor kidneys.4.The donor kidney GFR and the allograft eGFR at 1 month post-transplant were correlated with the severity of the histo-pathological changes(r=-0.692,p=0.003;r=-0.363,P=0.07).5.CD133 positive cells were found in renal interstitial totally in 6 cases(16.7%) of all 36 specimens; the expression of antigen CD133 seemed higher in tubular epithelial cells of cadaveric kidneys than that of living donor kidneys.6.3 donors with the histological score＞3 were treated with drugs beneficial to the kidney post-operation and found no hypertension,proteinuria or abnormal serum creatinine.7.During the period of follow-up(36～272 d),7 recipients suffered from acute rejection,of which 2 suspect rejection cases and 2 borderline rejection cases that diagnosed based on the founding of initial kidney biopsies.Conclusion:Time-Zero Biopsy was validated safe,reliable and easy to find potential histological changes that difficult detected by non-invasive inspection.The incidence of histological changes in donor kidney was high and it was closely related to donor age.In a certain period,prolonged cold ischemia time may not lead to clear changes in histo-pathology.The expression of CD133 that may promote the kidney to recover from the ischemic damage started in very early stage and increased with time.The severity of the histo-pathological changes was negatively correlated with donor kidney function and may predict the allograft short-term function.Time-Zero Biopsy was a scientific and effective approach to assess the donor kidney quality and it had significance in terms of predicting the allograft function and outcome,providing a reference point for analysis of subsequent biopsies,in favor of directional treatment and disease prevention for both donors and recipients,offering the histo-pathological evidence for the research in the mate kidneys and establishing specimens treasury for related study.Based on the validation with a larger sample size and improvement in safety,Time-Zero Biopsy should become a routine inspection item gradually.