Objective To retrospectively analyze the incidence of thrombotic complications of kidney transplantation from deceased pediatric donors and the related influencing factors in the Second XiangyaHospital. Methods A retrospective analysis of 357 cases of kidney transplantation from deceased pediatric donors in our hospital between January 2012 and December, 2018  was performed. The cases are divided into threegroups as following: 297 cases of single kidney transplant as group 1, 32 cases of double kidney transplant recipientswho meet the three "5" principles（donor age ＞ 5 month, donor weight ＞ 5 kg, renal length ＞ 5 cm）as group 2,  

a total number of 28 cases of double kidney transplant recipients who did not meet the three "5" principle as group 3. Then the relationship between the incidence of thrombotic complications and donor age, donor renal size and theoperation methods were analyzed. Results In the group of 297 single renal transplant recipients, 2 cases hadthrombotic complications; the incidence was 0.67%, which was caused by surgical error. There were no thromboticcomplications for 32 recipients of double kidney transplantation in the group 2, however, one patient developedrenal artery stenosis. Five cases had renal embolization in those using separate double kidney transplant operationin group 3, includng 3 cases of single renal artery embolism, 1 case of bilateral renal artery embolization and 1 case of single renal vein embolism. The incidence was 17.8% in group 3. However, 18 cases of recipients who receiving“en bloc kidney transplantation（EBKT）using the distal abdominal aorta as an outflow tract "had no embolismevents. Conclusion The incidence of thrombotic complications of kidney transplantation from deceased pediatric donors is related to donor age, donor kidney size and surgical technique. Donor age ＜ 5 months, donor weight ＜ 5 kg and donor kidney length ＜ 5 cm, the incidence of embolism was significantly increased.“EBKT using the distalabdominal aorta as an outflow tract”had a low incidence of embolism，seemed to be an effective method to solve theproblem of high incidence of embolism in kidney transplantation from neonatal donors, but expanded samples size andlong-term follow-up are still needed.

Objective To investigate the open surgical technique and its effect on ureteral stricture after renal transplantation. Methods A total of 166 cases who underwent single renal transplantations in department of urology, Beijing Friendship Hospital, Capital Medical University from January 2019 toJanuary 2020 were enrolled. The clinical data of 5 cases of ureteral stricture who received open operative treatment after renal transplantation were retrospectively analyzed. Baseline and surgical data werecollected and shown. Results Among the 5 patients, there were 3 males and 2 females, with a meanage of 42.6 years. Two had diabetic nephropathy and three had glomerulonephritis. The mean diagnostictime of ureteral obstruction after renal transplantation was 143.8 d, the mean time of open surgery was209.8 d after renal transplantation, and the mean serum creatinine level at the time of the diagnosis of obstructionwas 271.94 μmol/L. All the patients were confirmed by imaging examination due to the presence of hydronephrosis and progressive increase of serum creatinine, the renal function was first rescued by internal stents or percutaneousnephrostomy. After the renal function was stabilized, and according to the location of the stenosis segment, 3 patients underwent ureterovesical reanastomosis, 1 patient underwent ureteral end-to-end anastomosis between primary ureter and the ureter from graft. One patient underwent ureteroneocystostomy with a boari flap. The averageoperation time was 2.6 h, and the average intraoperative blood loss was 32 ml. All the 5 patients had a good prognosis.The average serum creatinine recovered to 111.5 μmol/L after the open surgery, with normal urine volume and nosurgical complications. After a follow-up for 6 months, none of the 5 patients had ureteral obstruction. ConclusionUreteral obstruction is one of the common complications after renal transplantation. The medium and long-term effectsof endourologic surgery are limited. Open surgery according to different obstruction sites is an effective plan for the treatment of ureteral stricture of transplanted kidney.

Objective To analyze the results of the determination of Tacrolimus（Tac）concentration in wholeblood by chemiluminescent microparticle immunoassay and latex enhanced immunosuppression. Methods The whole blood concentration of tacrolimus in 96 renal transplant recipients was parallelly measured by chemiluminescentmicroparticle immunoassay and latex enhanced immunosuppression, the results of different tests were compared and the correlation and regression were analyzed. Results The concentration of tacrolimus measured bychemiluminescent microparticle immunoassay（5.78 ± 2.18）μg/L was lower than that measured by latex enhanced immunosuppression（6.51±2.32）μg/L, and the difference was statistically significant（P ＜ 0.001）. There was a significant positive correlation between the two methods（r ＝ 0.9676，P ＜ 0.0001）, besides, the results of the twomethods were in accordance with the linear regression equation Y ＝ 0.551+1.032X（X was the chemical radio-particle immunoassay, Y was the latex enhanced immunosuppression）. Conclusion There was a good correlationbetween the two methods, but due to the significant  difference, comparison between each other cannot be made. The two methods can be calculated by linear regression equation. It is suggested that the same method should be selected for the same patient to monitor the whole blood concentration of tacrolimus in the long run, so as to provide accurate and reliable basis for clinical individual drug application.

obtained by clippingSD rat thoracic aorta for 30 minutes as warm ischemia；rat NMP system was established in vitro. According to differentmethods of preservation of the donor livers，the experiment was divided into: Normal group（n ＝ 6），serum and livers were retained for use ；NMP group（n ＝ 30），livers were collected after 4，6，and 8 h，outflow and inflow perfusatewas collected at 0，2，4，6 and 8 h after infusion for testing ；static cold storage（SCS）group（n ＝ 6），the livers were flushed out of the blood with 20 ml 4 ℃ UW solution and were collected after 6 h of SCS in UW solution at 4 ℃ .Liver function in outflow perfusate was detected by biochemical methods ；liver tissue histopathology was observed by hematoxylin-eosin staining ；hepatocyte ultrastructure was observed by transmission electron microscopy ；hepatocyteapoptosis was detected by terminal deoxynucleotidyl transferase dUTP nick end labeling ；endothelin-1，endothelialnitric oxide synthase（eNOS），inducible nitric oxide synthase（iNOS），von Willebrand factor（vWF），intercellular adhesion molecule（ICAM-1）and intervascular adhesion molecule -1 （VCAM-1）expression were detected byWestern blot. Results Compared with SCS，NMP significantly improved the histological damage of DCD donorlivers，the Suzuki’s score of NMP group（3.40±0.55）is significantly lower than that of SCS group（7.00±0.71，F ＝ 229.75，P ＜ 0.05）；reduced hepatocytes apoptosis，the number of apoptotic cells in the NMP group（9.80±1.48）was significantly lower than that in the SCS group（33.40±4.39，F ＝ 166.58，P ＜ 0.05）；meanwhile，NMP could repair liver mitochondrial damage，the number of irreversible damaged mitochondria in the NMP group（1.60±0.55）was significantly lower in the SCS group（2.80±0.45，F ＝ 36.29，P ＜ 0.05）. It was further found that NMPcould improve DCD liver through: ① Inhibiting intercellular adhesion and improving endothelial cell damage ；compared with SCS，NMP significantly inhibited the expression of ICAM-1（F ＝ 1728.45，P ＜ 0.05），VCAM-1 （F ＝ 254.72，P ＜ 0.05）and vWF（F ＝ 595.30，P ＜ 0.05）in the liver. ② Improving liver ET-1 / NOS balance and microcirculation perfusion ；compared with SCS，NMP significantly inhibited the expression of ET-1（F ＝ 1372.51，P ＜ 0.05）and iNOS（F ＝ 1102.20，P ＜ 0.05）in the liver and promoted the expression of eNOS（F ＝ 271.66，P ＜ 0.05）. Conclusion NMP could improve the microcirculation of DCD donor liver and improve the quality of donor liver. The mechanism may rely on its role in inhibiting intercellular adhesion，improving sinusoidal endothelialinjury and microcirculation perfusion. 

Objective To investigate the risk factors of IgA nephropathy recurrence after kidney transplantation. Methods A total of 149 kidney failure patients with primary IgA nephropathy who received kidney transplantation at the Organ Transplantation Center of Zhengzhou People's Hospital from January 2008 to December 2019 were selected as the study subjects. According to the results of the protocol kidney biopsy，the recipients were divided into the recurrent group（40 cases）and the non-recurrent group（109 cases）. Gender，age，donor type，dialysis duration，progression to end-stage renal disease（ESRD），history of transplantation，historyof hypertension and diabetes，history of postoperative infection，immunosuppressive regimen，HLA mismatchnumber，and risk factors for postoperative recurrence were recorded in the two groups. Results Compared withthe non-recurrent group，there were no statistically significant differences in gender，number of kidney transplants，diabetes，hypertension，immunosuppressive regimen，postoperative infection history，dialysis time between the two groups（P ＞ 0.05）. Logistic analysis showed that donor origin，recipient age and HLA mismatch were the risk factors for IgAN recurrence after renal transplantation，and the differences were statistically significant（All P ＜ 0.05）. Conclusion The recurrence of IgA nephropathy after kidney transplantation was related to the source of donor，recipient age and HLA mismatch. Intervention measures should be taken according to the above factors to provide ideas for clinical control of IgAN recurrence. 

Objective To compare the safety and efficacy between steroid withdrawal/avoidance regimenand steroid-based immunosuppressive regimen in pediatric renal transplant recipients. Methods The relevant literatures of steroid withdrawal/avoidance regimen and steroid-based regimen in pediatric renal transplant recipients were searched in the databases of PubMed，Embase，Cochrane Library，Web of Science，CNKI，Wanfang Data and VIP. The data were evaluated by RevMan 5.4 software. Results A total of 634 patients with 6 randomized controlled trials were included，including steroid withdrawal group（n ＝ 320）and steroid-based group（n ＝ 314）. The results showed significant improvement in height in steroid withdrawal/avoidance group compared with steroid-based group〔MD ＝ 0.39，95%CI（0.14，0.65），P ＜ 0.01〕， and prepuberty patients benefit more from steroid withdrawal/avoidance. The increase in height was not accompanied by an increase in rejection or a decrease in the survival rateof patients and allografts in the short term，and the long-term prognosis was also optimistic. Conclusion Thesteroid withdrawal/avoidance regimen in pediatric renal transplant recipients can significantly improve the growth ofchildren's height，among which the prepuberty patients benefit more. Most importantly，the benefits of growth and development were not at the expense of an increase in acute rejection in the short term，and long-term follow-up data showed that recipient and kidney survival were comparable to those in steroid-based recipients.

Objective To evaluate the efficacy，safety and economy of tenofovir（TDF）monotherapy inthe prevention of hepatitis B Virus（HBV）recurrence after hepatitis B immunoglobulin（HBIG）withdrawal in livertransplantation（LT）recipients. Methods HBV-related LT patients were selected in our hospital. They weredivided into the TDF monotherapy group and entecavir（ETV）combined with HBIG group. We collected clinicaland laboratory data of patients and compared the preventive effects，adverse effects and drug costs of the two drug regimens. Results Until June 30th，2019，ten patients in the monotherapy group and 28 patients in the combinedgroup were included. Mean follow-up time of the two groups were 13.50 and 13.03 months, respectively. One patientsin the monotherapy group（10.00%）and two patients in the combined group（7.14%）showed recurrence of HepatitisB surface antigen（HBsAg） positive. All patients had consistently negative hepatitis B virus DNA（HBV-DNA）afterLT. One patient（3.57%）in the combined group died. The cost of monotherapy group was significantly lower than that of the combined group（490 yuan/month vs. 1952.55 yuan/month，P ＜ 0.01）. Conclusion Compared with ETVand HBIG，it is effective，safe and economical for patients to discontinue HBIG and use TDF monotherapy in theprevention of HBV recurrence after LT.