Objective To investigate the main causes of kidney transplantation graft loss，and analyze independent risk factors for loss of graft by chronic rejection. Methods The prognosis of all kidney transplantrecipients from January 2015 to January 2023 was retrospectively analyzed. A total number of 14 recipients with renal graft loss due to chronic rejection were selected as the case group，and 56 recipients corresponding to 28 donors without donor kidney loss were selected as the control group. Clinical data of the two groups of recipients and corresponding donors were retrospectively analyzed，and logistic regression analysis was carried out. Results Inthe past 8 years，147 cases experienced renal graft loss，including 67 cases of renal graft dysfunction and 80 cases of death. The top three causes of renal graft dysfunction were chronic rejection，vascular embolism and relapse of nephropathy. The top three causes of death in transplant patients were infection，cardiovascular accidents and digestive complications. Multivariate logistic regression analysis showed that there was a statistically significant difference in donor age between the case group and the control group（P ＝ 0.012）. Conclusion In our center， chronic rejection was the main cause of renal graft failure. The leading causes of death in kidney transplant patients are infection and cardiovascular problems. Age of the donors is the independent risk factor for renal graft loss bychronic rejection. 

肾移植 ； 肺部感染 ； 宏基因二代测序 ； 治疗经验

Objective Establish model of abdominal heterotopic heart transplantation in mice and summarize the experience to provide animal model support for further study of organ transplantation immunology. Methods Inbred BALB/c（n ＝ 30）and C57BL/6（n ＝ 30）mice were selected as donors，and inbred BALB/c（n ＝ 60）mice were used as recipients. The ascending aorta of the donor was anastomosed to the abdominal aorta of the recipient，and the pulmonary artery of the donor was anastomosed to the inferior vena cava of the recipient respectively to establish the heterotopic heart transplantation model. The survival time and the rejection of grafts were observed postoperatively. Results The successful rate of transplantation was 85%（51/60）. The donoroperation time was（7.0±1.0）min，and the recipient operation time was（60±10）min. The vascular anastomosis time was（25±3.0）min. After the transplantation，no immunosuppressive agent was used，and the survival time of the graft was（7.6±0.9）d. The graft on the fifth day，the seventh day showed typical rejection by histopathology. Conclusion Skilled microsurgical techniques and timely management of surgical complications are key to the successful establishment of abdominal heterotopic heart transplantation in mice. 

Objective To explore the risk factors for recurrent （≥ 2 times） pneumonia in elderlykidney transplant recipients after surgery. Methods Retrospective analysis was performed from the clinical data of 119 elderly kidney transplant recipients who underwent kidney transplantation at the Eighth Medical Center of the People's Liberation Army General Hospital from January 2010 to January 2024. According to whether pneumonia occurs repeatedly （≥ 2 times） after kidney transplantation， elderly recipients were divided into two groups， with 11 cases in the recurrent pneumonia group and 108 cases in the non-recurrent pneumonia group. Relevant clinical data were compared between the two groups， including the general basic information of the recipient （gender， age， height， weight， smoking history，etc.）， as well as the relevant clinical data （the time of dialysis before kidney transplantation， the maintenance treatment plan of immunosuppressant after surgery， whether there was delayed recovery of kidney function after transplantation， whether there was a decrease in white blood cells after transplantation， serum creatinine level at discharge， whether there was diabetes before and after surgery， and whether there was viral hepatitis B infection， etc.）. We conducted univariate analysis and multivariate logistic regression analysis to explore the risk factors for recurrent pneumonia in elderly kidneytransplant recipients after surgery. Results The incidence of recurrent pneumonia in elderly kidney transplant recipientsafter surgery was 9.24% （11/119）， and one patient in the case group died from severe pneumonia， with a mortality rate of 9.1% （1/11）. Smoking history （OR ＝ 13.15，95% CI ＝ 2.406 ～ 71.91，P ＝ 0.003） and postoperative leukopenia （OR ＝ 6.050，95% CI ＝ 1.248 ～ 29.32，P ＝ 0.025） were risk factors for recurrent pneumonia in elderly kidney transplant recipients. Conclusion Smoking history and postoperative leukopenia increase the risk of recurrent pneumonia in elderly kidney transplant recipients. So we should strengthen postoperative health education for elderly kidney transplant recipients， encourage smoking cessation， and prevent and treat postoperative leukopenia.