| At present,the traditional indicators such as serum creatinine and blood urea nitrogen are commonly used to evaluate the quality of donor kidney and predict the recovery of renal function post-transplantation.However,the specificity and stability of these indicators are poor.Therefore,it is very promising to identify some biomarkers with high sensitivity and specificity that can effectively guide us to evaluate donor kidney and predict graft renal function post-transplant.Some articles have reported the role of new biomarkers in donor evaluation,such as neutrophil gelatinase-associated lipocalin(NGAL),kidney injury factor 1(KIM-1),and metalloproteinase tissue inhibitor 2(TIMP-2),urinary N-acetyl-β-D-glucosaminidase(uNAG),etc,which can evaluate kidney function and predict kidney damage because these biomarkers in the body is determined or Partially determined by the kidneys and the urine or blood concentration of these biomarkers changes in time after kidney injury,so they can reflect glomerular and tubular damage in time.In summary,we analyzed the relationship between the concentration of biomarkers in both donor’s and recipient’s blood and urine specimen and the traditional indicator of creatinine;we also performed the biomarker expression in the zero-time biopsies of donor kidneys.We summarized the role of biomarkers in assessing donor kidneys after cardiac death and predicting graft renal function post-transplantation.Method1.Ethical declaration2.Research object Donor inclusion criteria:Han,age>14 or<65 years,no history of infectious diseases,donors who meet the DCD donation conditions.Receptor inclusion criteria:Patients with end-stage renal disease who need kidney transplants;Exclusion criteria for recipients:Age<18 years,diagnosed as a patient with infectious diseases such as cancer and hepatitis.Finally,a total of 27 donors and 54 their recipients were included.3.Experimental specimen acquisition and detection method(1)After admission,donors were given serum and urine specimens before donation surgery on the donation day(DO);we received recipients serum and urine samples pre-transplantation,1 day,3 days,7 days,and 14 days post-transplantation.The specimens were collected and pretreated for analysis;furthermore,pre-implantation biopsies were collected and examined by fast frozen section then take H-E stain.(2)ELISA Quantitative:Quantitative analysis of neutrophil gelatinase-associated lipocalin(NGAL),kidney injury factor 1(KIM-1),tissue inhibitor of metalloproteinase 2(TIMP-2)and N-acety1-β-D glucosaminidase(uNAG)in donors and recipients blood and urinary by ELISA.(3)Donor pre-implantation biopsies was performed with hematoxylin-eosin staining(HE staining)and immunohistochemistry analysis:After renal biopsy HE staining,graded according to Randhawa score criteria:the expression of neutrophil gelatinase associated lipocalin(NGAL),Kidney Injury Factor 1(KIM-1),Tissue Inhibitor of Metalloproteinase 2(TIMP-2),Urinary N-Acetyl-β-D-glucosaminidase(uNAG)in Renal Lesions by immune-histochemical detection.4.Collection of other dataWe recorded basic information for the donor and recipient,such as gender,age,history,body weight(kg),serum creatinine,cause of death of the donor,cold ischemia time for the kidneys,etc.5.Experimental grouping and data analysis(1)Biomarker concentration in serum and urine specimens①The donors were divided into acute kidney injury group(AKI group)and non-acute kidney injury group(non-AKI group)according to whether donors kidney had acute kidney injury.We compared of Biomarker concentration in Serum and Urine Specimen between two Groups.②According to the recipient creatinine level on D7,the donors were divided into two groups:the reduced graft function group(RGF group)and the immediate graft function group(IGF group).We compared of Biomarker concentration in Serum and Urine Specimen between two(2)Differences in expression of biomarkers in renal biopsies6.Statistical analysisResult:1.Biomarker concentration in serum and urine specimens(1)Comparison between AKI group and non-AKI group:The concentrations of serum TIMP-2,serum KIM-1,urinary TIMP-2,and urinary KIM-1 in the AKI group were higher than those in the non-AKI group(P =0.001,0.043,0.005,and 0.047,respectively).(2)RGF group compared with IGF group:serum NGAL and serum TIMP-2 in RGF group were higher than IGF group(P = 0.048,0.034 respectively).(3)RGF receiver operating characteristic curve(ROC curve):The area under the curve(AOROC)of serum TIMP2+uNAG+ serum creatinine on DO was 0.871(P=004),the area under the curve(AOROC)of serum creatinine alone onGroups.The mentioned grouping methods are shown in the following figure:DO was 0.714(P=0.097).(4)The concentration of serum TIMP-2 on the third day post-transplantation(D3)highly correlated with the occurrence of RGF.2.Differences in expression of biomarkers in renal biopsy pre-transplantation:A total of 10 biopsies specimens were retained,and TIMP-2 was expressed in all biopsies.Expression scores were based on semi-quantitative analysis(Note:It is based on the percentage of staining intensity and the percentage of positive cells.The cytoplasm of the tissue section stained as light yellow to tan is a positive cell marker,and the product of staining intensity and percentage of positive cells is 0:negative,1-4 Weak positive,5-8 moderately positive,9-12 strong positive):6 out 10 biopsies expression score was 0,2 biopsies had a score of 1,1 biopsy had a score of 2,1 biopsy had a score of 3,and there was no significant difference in TIMP-2 expression between RGF group and IGF group.Conclusion:1.Donor serum TIMP-2 and uNAG levels on DO can be used to evaluate the quality of donor kidneys.2.Donor serum TIMP-2,uNAG,and serum creatinine levels on DO can predict RGF in recipients3.The recipient serum TIMP-2 level on the third day post-transplantation(D3)can predict the graft renal function on the seventh day post-transplantation(D7),that is,it can predict RGF in the graft kidney. |
