Predictive Score Model for Delayed Graft Function Based on Hypothermic Machine Perfusion Variables in Kidney Transplantation / 中华医学杂志(英文版)

Background@#Hypothermic machine perfusion (HMP) is being used more often in cardiac death kidney transplantation; however, the significance of assessing organ quality and predicting delayed graft function (DGF) by HMP parameters is still controversial. Therefore, we used a readily available HMP variable to design a scoring model that can identify the highest risk of DGF and provide the guidance and advice for organ allocation and DCD kidney assessment.@*Methods@#From September 1, 2012 to August 31, 2016, 366 qualified kidneys were randomly assigned to the development and validation cohorts in a 2:1 distribution. The HMP variables of the development cohort served as candidate univariate predictors for DGF. The independent predictors of DGF were identified by multivariate logistic regression analysis with a P < 0.05. According to the odds ratios (ORs) value, each HMP variable was assigned a weighted integer, and the sum of the integers indicated the total risk score for each kidney. The validation cohort was used to verify the accuracy and reliability of the scoring model.@*Results@#HMP duration (OR = 1.165, 95% confidence interval [CI]: 1.008-1.360, P = 0.043), resistance (OR = 2.190, 95% CI: 1.032-10.20, P < 0.001), and flow rate (OR = 0.931, 95% CI: 0.894-0.967, P = 0.011) were the independent predictors of identified DGF. The HMP predictive score ranged from 0 to 14, and there was a clear increase in the incidence of DGF, from the low predictive score group to the very high predictive score group. We formed four increasingly serious risk categories (scores 0-3, 4-7, 8-11, and 12-14) according to the frequency associated with the different risk scores of DGF. The HMP predictive score indicates good discriminative power with a c-statistic of 0.706 in the validation cohort, and it had significantly better prediction value for DGF compared to both terminal flow (P = 0.012) and resistance (P = 0.006).@*Conclusion@#The HMP predictive score is a good noninvasive tool for assessing the quality of DCD kidneys, and it is potentially useful for physicians in making optimal decisions about the organs donated.

Beneficial Effect of Moderately Increasing Hypothermic Machine Perfusion Pressure on Donor after Cardiac Death Renal Transplantation / 中华医学杂志(英文版)

Background@#Vascular resistance and flow rate during hypothermic machine perfusion (HMP) of kidneys is correlated with graft function. We aimed to determine the effects of increasing HMP pressure versus maintaining the initial pressure on kidney transplantation outcomes.@*Methods@#We retrospectively reviewed the data of 76 primary transplantation patients who received HMP-preserved kidneys from 48 donors after cardiac death between September 1, 2013, and August 31, 2015. HMP pressure was increased from 30 to 40 mmHg (1 mmHg = 0.133 kPa) in kidneys with poor flow and/or vascular resistance (increased pressure [IP] group; 36 patients); otherwise, the initial pressure was maintained (constant pressure group; 40 patients). Finally, the clinical characteristics and transplantation outcomes in both groups were assessed.@*Results@#Delayed graft function (DGF) incidence, 1-year allograft, patient survival, kidney function recovery time, and serum creatinine level on day 30 were similar in both groups, with improved flow and resistance in the IP group. Among patients with DGF, kidney function recovery time and DGF duration were ameliorated in the IP group. Multivariate logistic regression analysis revealed that donor hypertension (odds ratio [OR]: 1.43, 95% confidence interval [CI]: 1.02-2.06, P = 0.035), donor terminal serum creatinine (OR: 1.27, 95% CI: 1.06-1.62, P = 0.023), warm ischemic time (OR: 3.45, 95% CI: 1.97-6.37, P = 0.002), and terminal resistance (OR: 3.12, 95% CI: 1.76-6.09, P = 0.012) were independent predictors of DGF. Cox proportional hazards analysis showed that terminal resistance (hazard ratio: 2.06, 95% CI: 1.32-5.16, P = 0.032) significantly affected graft survival.@*Conclusion@#Increased HMP pressure improves graft perfusion but does not affect DGF incidence or 1-year graft survival.

Early Immunosuppressive Exposure of Enteric-Coated-Mycophenolate Sodium Plus Tacrolimus Associated with Acute Rejection in Expanded Criteria Donor Kidney Transplantation / 中华医学杂志(英文版)

<p><b>Background</b>Immunosuppressive agents are still inefficient in preventing biopsy-proven acute rejection (BPAR) after expanded criteria donor (ECD) kidney transplantation. The aim of this study was to investigate the relationships between early immunosuppressive exposure and the development of BPAR.</p><p><b>Methods</b>We performed a retrospective study of 58 recipients of ECD kidney transplantation treated with enteric-coated-mycophenolate sodium, tacrolimus (Tac), and prednisone. The levels of mycophenolic acid-area under the curve (MPA-AUC) and Tac Cwere measured at the 1 week and the 1 month posttransplant, respectively. The correlation was assessed by multivariate logistic regression.</p><p><b>Results</b>The occurrence rates of BPAR and antibody-mediated rejection were 24.1% and 10.3%, respectively. A low level of MPA-AUC at the 1 week posttransplant was found in BPAR recipients (38.42 ± 8.37 vs. 50.64 ± 13.22, P < 0.01). In addition, the incidence of BPAR was significantly high (P < 0.05) when the MPA-AUClevel was <30 mg·h·L at the 1 week (15.0% vs. 44.4%) or the Tac Cwas <4 ng/ml at the 1 month posttransplant (33.3% vs. 21.6%). Multivariable logistic regression analysis showed that the MPA-AUC at the 1 week (OR: 0.842, 95% CI: 0.784-0.903) and the Tac Cat the 1 month (OR: 0.904, 95% CI: 0.822-0.986) had significant inverse correlation with BPAR (P < 0.05).</p><p><b>Conclusions</b>Low-level exposure of MPA and Tac Cin the early weeks posttransplant reflects an increased acute rejection risk, which suggested that MPA-AUC <30 mg·h·L and Tac C <4 ng/ml should be avoided in the first few weeks after transplantation.</p>

Predictive Score Model for Delayed Graft Function Based on Easily Available Variables before Kidney Donation after Cardiac Death / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>How to evaluate the quality of donation after cardiac death (DCD) kidneys has become a critical problem in kidney transplantation in China. Hence, the aim of this study was to develop a simple donor risk score model to evaluate the quality of DCD kidneys before DCD.</p><p><b>METHODS</b>A total of 543 qualified kidneys were randomized in a 2:1 manner to create the development and validation cohorts. The donor variables in the development cohort were considered as candidate univariate predictors of delayed graft function (DGF). Multivariate logistic regression was then used to identify independent predictors of DGF with P < 0.05. Date from validation cohort were used to validate the donor scoring model.</p><p><b>RESULTS</b>Based on the odds ratios, eight identified variables were assigned a weighted integer; the sum of the integer was the total risk score for each kidney. The donor risk score, ranging from 0 to 28, demonstrated good discriminative power with a C-statistic of 0.790. Similar results were obtained from validation cohort with C-statistic of 0.783. Based on the obtained frequencies of DGF in relation to different risk scores, we formed four risk categories of increasing severity (scores 0-4, 5-9, 10-14, and 15-28).</p><p><b>CONCLUSIONS</b>The scoring model might be a good noninvasive tool for assessing the quality of DCD kidneys before donation and potentially useful for physicians to make optimal decisions about donor organ offers.</p>

Construction and identification of Ksp-cadherin-Gpx1-Klk1 expression vector / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct a Gpx1 and klk1 recombinant vector containing the kidney-specific promoter Ksp-cadherin.</p><p><b>METHODS</b>Human Gpx1, Klk1 and Ksp-cadherin cDNAs were amplified with PCR and inserted in a stepwise manner into the expressive vector pIRES-EGFP to construct the recombinant vector Ksp-cadherin-Gpx1-Klk1. The constructed vector was verified with restriction enzyme digestion and sequence analysis.</p><p><b>RESULTS AND CONCLUSION</b>The recombinant expression vector Ksp-cadherin-Gpx1-Klk1 was constructed and identified successfully, which provides a potent tool for preparing transgenic animals to investigate gene therapy for ischemia-reperfusion injury in kidney transplantation.</p>

Co-culture of cryopreserved rat islets with small intestinal submucosa / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the feasibility and benefits of co-culture of cryopreserved islets with small intestinal submucosa (SIS).</p><p><b>METHODS</b>Purified rat islets cryopreserved for one month were divided into SIS group and control group, and after culture in standard islet culture media RPMI1640 for 1 week, the morphology and function of the islets were assessed.</p><p><b>RESULTS</b>The SIS protects the fragile islets from damage by cryopreservation, and increased the recovery from (60.6-/+3.3)% to (91.7-/+1.8) % (P<0.05). Compared with the control group, incubation of the islets of the SIS group in high-glucose (16.7 mmol/L) solution resulted in significantly enhanced insulin secretion (23.7-/+1.6 vs 12.5-/+1.1 mU/L, P<0.05). When the islets were incubated in high-glucose solution containing theophylline, the calculated stimulation index of SIS group was about 3-fold higher than that of the control group.</p><p><b>CONCLUSION</b>Co-culture of cryopreserved rat islets with SIS can increase the recovery of islet cells and improve their function.</p>

Recombinant adenovirus-mediated human cytosolic glutathione peroxidase gene transfection protects vascular endothelial cells from oxidative damage / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the protective effect of recombinant adenovirus-mediated human cytosolic glutathione peroxidase (hCGPx) gene transfection on vascular endothelial cells ECV304 from oxidative damage.</p><p><b>METHODS</b>pGEM-T Easy Vector containing hCGPx cDNA and recombinant adenovirus shuttle plasmid pACCMV-pLpA were used to construct the shuttle plasmid pACCMV-hCGPx for cotransfection of 293 cells with pJM17, thereby to obtain the recombinant adenovirus AdCMV-hCGPx. Cultured ECV304 cells were transfected with AdCMV-hCGPx for 24, 48 and 72 h, respectively, with the cells transfected with the empty vector serving as control, and hCGPx gene expression was then examined in the transfected cells. The transfected cell viability and apoptotic cell ratio were evaluated after treatment of the cells with H(2)O(2).</p><p><b>RESULTS</b>The expression ratio of hCGPx gene was significantly higher in the AdCMV-hCGPx-transfected cells than in those with empty vector transfection (P<0.01). The hCGPx gene-transfected cells showed significantly higher viability and significantly lower apoptotic ratio than the control cells following challenge with H(2)O(2)-induced oxidative damage.</p><p><b>CONCLUSION</b>hCGPx gene transfer mediated by recombinant adenovirus protects the vascular endothelial cells from oxidative damage in vitro, possibly due to the antioxidative and apoptosis-inhibiting effect of hCGPx.</p>

Isolation and culture of adult Sertoli cells and their effects on the function of co-cultured allogeneic islets in vitro / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Globally, 180 million people suffer from diabetes mellitus. Islet transplantation is believed to be an almost ideal therapy for insulin-dependent patients. How to maintain the viability and the function of isolated human islets is a challenge in clinical practice. Sertoli cells are considered 'nurse cells' in the seminiferous tubules and have been used in cell graft protocols for neurodegenerative diseases and diabetes in many studies. Many researchers have used immature murine testes as the primarily source of Sertoli cells in islet transplantation because they are easily purified. Mature human Sertoli cells have been seldom investigated. In the present study, we developed a method for the isolation and culture of Sertoli cells derived from adult human testes, and investigated their effects on the function of allogeneic islets when they were cultured together in vitro.</p><p><b>METHODS</b>Adult Sertoli cells were prepared successfully by two-step enzyme digestion with trypsin, collagenase and hyaluronidase. They were identified by morphological characteristics and their activity was determined by MTT colorimetry over a 28-day culture time in vitro. A glucose-stimulated insulin secretion test was performed to detect the effects of Sertoli cells on allogeneic islets' function when they were co-cultured for 21 days in vitro.</p><p><b>RESULTS</b>In cultured cells, mature human Sertoli cells accounted for more than 90% of total cells. The activity of Sertoli cells reached 95% and they remained highly cytoactive for a long time in vitro (P > 0.05). Compared with the islets cultured alone, the co-cultured islets with allogeneic Sertoli cells maintained higher sensitivity to glucose stimulation for the duration of the experiment (P < 0.01).</p><p><b>CONCLUSIONS</b>A method of isolation and culture of Sertoli cells from adult testes has been established. Sertoli cells could enhance allogeneic islets' function when they were co-cultured in vitro. They could be a helper cell in islet transplantation.</p>