Rejection in kidney transplantation are significant barriers affecting the survival of recipients and transplant kidneys. To further standardize the clinical diagnosis and treatment of rejection in kidney transplant recipients in China, the Branch of Organ Transplantation of Chinese Medical Association and Branch of Organ Transplantation Physician of Chinese Medical Doctor Association organized kidney transplant experts, transplant immunologists and other experts. Based on the " Technical specification for clinical diagnosis and treatment of renal transplant rejection (2019 edition)" issued by Branch of Organ Transplantation of Chinese Medical Association, and referring to recent domestic and international research findings, expert consensus, guidelines, and mature clinical experience, combined with the current clinical situation of rejection diagnosis and treatment in kidney transplant recipients in China, the "Guidelines for clinical diagnosis and treatment of rejection in kidney transplant recipients in China" have been formulated. The content covers the clinical standard diagnosis and treatment of kidney transplant hyperacute rejection, acute rejection (acute T cell-mediated rejection, acute antibody-mediated rejection), and chronic rejection (chronic active T cell-mediated rejection, chronic active antibody-mediated rejection), aiming to provide theoretical and clinical practice references for the clinical diagnosis and treatment of rejection in Chinese kidney transplant recipients, with the goal of improving and promoting the quality of kidney transplantation.

The incidence of perioperative complications in kidney transplantation is relatively high. Perioperative management of kidney transplantation is one of the key factors for the early recovery of kidney transplant recipients and the successful recovery of renal function, and it also becomes a new challenge for the kidney transplant team. In order to further standardize the perioperative technical operation of kidney transplantation and improve the clinical diagnosis and treatment level of kidney transplantation during the perioperative period, the Branch of Organ Transplantation of Chinese Medical Association and Branch of Organ Transplantation Physician of Chinese Medical Doctor Association organized domestic experts in clinical transplantation, nursing, epidemiology and other related fields to adopt the 2009 edition of Oxford University evidence grading and recommendation strength grading standards. This paper provides detailed evidence-based recommendations on 22 clinical issues related to perioperative renal transplantation in terms of nursing and monitoring, volume assessment, nutrition and fluid rehydration, water-electrolyte acid-base balance and so on, aiming to improve the clinical prognosis of perioperative renal transplantation in China through evidence-based clinical practice.

The Branch of Organ Transplantation of Chinese Medical Association has released the “Guideline on Application of Extracorporeal Membrane Oxygenation in the Protection of Deceased Donor Kidneys”. This guideline referred to the “Expert Consensus on the Application of Extracorporeal Membrane Oxygenation in the Protection of Organs from China Donation after Citizen′s Death (2016 Edition)” and “Technical Operation Specifications for Extracorporeal Membrane Oxygenation in the Protection of Deceased Donor Organ (2019 Edition)” as well as the literatures and guidelines published. This document raises 13 clinical questions and provides recommendations based on existing evidence, aiming to further standardize the application of extracorporeal membrane oxygenation in the protection of deceased donor kidneys.

The implementation of the "Regulations on Organ Donation and Transplantation" (hereinafter referred to as the new "Regulations") and supporting documents has laid a solid foundation for improving the organ donation and transplantation work system in accordance with laws and regulations. In order to better publicize, implement, and carry out the new "Regulations" and supporting documents, and in response to the problems and challenges encountered in actual work, combined with the development of the national human organ donation and transplantation work system and the national work on determination of brain death, this article analyzes and discusses the construction of hospitals' organ donation and transplantation work systems and the systematic multidisciplinary collaboration mechanism for organ donation, as well as several issues that need attention by the ethics committees for organ transplantation. The aim is to provide references for the construction of ethics committees for organ transplantation in China and to promote the continuous and healthy development of China's organ donation and transplantation cause.

The rule of law is the fundamental approach to governance in modern states. The ethical issues arising from deceased organ donation activities have attracted high social attention. In order to ensure that deceased organ donation is in line with the interests and moral standards of the public, it is not enough to provide ethical guidance for the development of the organ donation cause through reflection alone. It is necessary to apply the concept of the rule of law, legal rules and procedural norms to the ethical governance of deceased organ donation. The newly revised "Regulations on Human Organ Donation and Transplantation" have established ethical guidelines that organ donation must follow, such as "benefit, do no harm, respect for life, fairness and justice, and compliance with laws and public order", as well as five major principles that must be adhered to in conducting ethical reviews of organ procurement, such as "voluntary and unpaid, informed consent, risk control, fairness and justice, and privacy protection". Faced with the increasing number of deceased organ donation cases and the ethical challenges they pose, it is recommended to establish a "National Human Organ Donation Ethics Committee," clarify the definition and judgment criteria of death from a legal perspective as soon as possible, and create an effective ethical risk monitoring and supervision mechanism. Continuously promote the progress of the organ donation within the legal framework, and effectively safeguard the public interest and basic rights.

Objective To explore the technical process and clinical application of laparoscopic combined upper midline incision minimally invasive liver transplantation. Methods A retrospective analysis was conducted on 30 cases of laparoscopic combined upper midline incision minimally invasive liver transplantation. The cases were divided into cirrhosis group (15 cases) and liver failure group (15 cases) based on the primary disease. The surgical and postoperative conditions of the two groups were compared. Results All patients successfully underwent laparoscopic "clockwise" liver resection, with no cases of passive conversion to open surgery or intolerance to pneumoperitoneum. In 6 cases, the right lobe was relatively large, and the right hepatic ligaments could not be completely mobilized. One case required an additional reverse "L" incision during open surgery. All patients successfully completed the liver transplantation, with no major intraoperative bleeding, cardiovascular events, or other occurrences in the 30 patients. The model for end-stage liver disease (MELD) score in the cirrhosis group was lower than that in the liver failure group (P<0.001). There were no statistically significant differences between the two groups in terms of age, surgical time, blood loss, anhepatic phase, or cold ischemia time (all P>0.05). During the perioperative period, there was 1 case of hepatic artery embolism, 1 case of portal vein anastomotic stenosis, no complications of hepatic vein and inferior vena cava, and 3 cases of biliary anastomotic stenosis, all of which occurred in the liver failure group. Conclusions In strictly selected cases, the minimally invasive liver transplantation technique combining laparoscopic hepatectomy with upper midline incision for graft implantation has the advantages of smaller incisions, less bleeding, relatively easier operation, and faster postoperative recovery, which is worthy of clinical promotion and application.

Objective To investigate the effect and mechanism of the signal transducer and activator of transcription 3 (STAT3) inhibitor Stattic on the rejection of mouse heart allograft. Methods BALB/c mice (donors) were used to transplant skin onto C57BL/6 mice (recipients). Four weeks later, memory CD4⁺ T cells (CD4⁺Tm) were isolated from the recipient mice's spleens. Mixed lymphocyte reaction experiment was conducted with C57BL/6 mouse splenocytes and CD4⁺Tm, and the EdU method was used to detect the effect of Stattic on CD4⁺Tm cell proliferation. A C57BL/6 mouse heart transplant (HTx) model was constructed, and the experiment was divided into four groups: Non-HTx group, HTx group, Tm/HTx group, and Tm/HTx+Stattic group. The survival of heart allografts in mice was observed daily. Hematoxylin-eosin staining was used to observe the histopathology of the heart allografts. Real-time fluorescent quantitative polymerase chain reaction was used to detect the expression levels of interferon (IFN)-γ, interleukin (IL)-2, IL-10, and transforming growth factor-β1 (TGF-β1) messenger RNA (mRNA) in the heart allografts. Enzyme-linked immunosorbent assay was used to detect the levels of IFN-γ, IL-2, IL-10, and TGF-β1 in the serum. Flow cytometry was used to detect the levels of CD4⁺Tm (CD4⁺CD44⁺CD62L⁺) in splenic lymphocytes. And Western blotting was used to detect the expression levels of STAT3 and p-STAT3 proteins in the heart allografts. Results When the concentration of Stattic exceeded 2.5 μmol/L, it could inhibit the proliferation of CD4⁺Tm cells. Compared with the HTx group, the Tm/HTx group showed shorter survival time of heart grafts, more severe histopathological damage, increased serum IFN-γ and IL-2 levels, decreased IL-10 and TGF-β1 levels, increased relative expression of IFN-γ and IL-2 mRNA, decreased relative expression of IL-10 and TGF-β1 mRNA in the heart allografts, increased proportion of CD4⁺Tm in splenic lymphocytes, and increased p-STAT3/STAT3 ratio in the heart allografts (all P<0.05). Compared with the Tm/HTx group, the Tm/HTx+Stattic group showed longer survival time of heart grafts, less severe histopathological damage, decreased serum IFN-γ and IL-2 levels, increased IL-10 and TGF-β1 levels, decreased relative expression of IFN-γ and IL-2 mRNA, increased relative expression of IL-10 and TGF-β1 mRNA in the heart allografts, decreased proportion of CD4⁺Tm in splenic lymphocytes, and decreased p-STAT3/STAT3 ratio in the heart allografts (all P<0.05). Conclusions Stattic may prolong the survival time of mouse heart allografts, and its mechanism may be related to the inhibition of CD4⁺Tm- mediated acute rejection.

Objective To construct programmed cell death protein-ligand 1(PD-LI)^hi tolerogenic dendritic cell (tol-DC) derived from bone marrow of DA rats and identify its immunological function. Methods DA rat bone marrow cells were extracted, combined with recombinant mouse granulocyte macrophage colony-stimulating factor and recombinant mouse interleukin (IL)-4, and cultured for 6 days in vitro to induce the differentiation of bone marrow cells into immature dendritic cells (imDC). Lipopolysaccharide was used to stimulate cell maturation and cultured for 2 days to collect mature dendritic cells (mDC). PD-L1 lentiviral vector virus stock solution or equivalent dose lentiviral stock solution was added, and PD-L1^hitol-DC and Lv-imDC were collected after culture for 2 days. The morphology of PD-L1^hitol-DC was observed by inverted phase contrast microscope and transmission electron microscope. Real-time fluorescence quantitative reverse transcription polymerase chain reaction, Western blotting and flow cytometry were used to detect the expression level of specific markers on cell surface. CD8⁺T cells derived from Lewis rat spleen were co-cultured with imDC, mDC, Lv-imDC and PD-L1^hitol-DC, respectively. The levels of inflammatory factors in the supernatant of each group were detected by enzyme-linked immunosorbent assay. The apoptosis of T cells and the differentiation of regulatory T cells (Treg) in each group were analyzed by flow cytometry. Results The morphology of PD-L1^hitol-DC modified by PD-L1 gene was consistent with tol-DC characteristics, and the expression levels of CD80, CD86 and major histocompatibility complex (MHC) on the surface were low. After mixed culture with CD8⁺ T cells, the levels of IL-10 and transforming growth factor (TGF) -β1 in the supernatant of PD-L1^hitol-DC group were higher, the levels of tumor necrosis factor (TNF) -α and IL-17A were lower, and the apoptosis of T cells and Treg differentiation were increased. Conclusions Overexpression of PD-L1 through lentiviral vectors may successfully induce the construction of bone-marrow derived PD-L1^hitol-DC in DA rats, promote the secretion of anti-inflammatory factors and T cell apoptosis, induce the differentiation of Treg, and inhibit the immune response of allogeneic CD8⁺T cells, which provides experimental basis for the next organ transplantation immune tolerance study.

Objective To explore the therapeutic effect and mechanism of umbilical cord mesenchymal stem cells (UC-MSC) in rats with primary graft dysfunction after lung transplantation. Methods Twenty-four male Lewis rats were randomly divided into donor and recipient groups, with 12 rats in each group. The recipients were further divided into 3 groups: blank control group, negative control group, and treatment group, with 4 rats in each group. The color, size and texture of the transplanted lungs were observed 72 h after lung transplantation. The ventilation status and progression of consolidation in the transplant lungs of rats in each group were evaluated by micro-CT. Plasma, transplant lung tissue and alveolar lavage fluid samples of recipient rats were collected. The wet/dry ratio of lung tissue was measured to evaluate the degree of pulmonary edema. Hematoxylin-eosin (HE) staining was used to evaluate the degree of lung tissue damage. Terminal deoxyribonucleic acid transferase mediated dUTP nick end labeling (TUNEL) staining was used to evaluate cell apoptosis. Myeloperoxidase (MPO) activity in lung tissue was detected, and enzyme-linked immunosorbent assay (ELISA) was used to detect interleukin (IL)-6, IL-10 and tumor necrosis factor (TNF)-α levels in plasma and alveolar lavage fluid. Results The appearance of the transplant lungs in the negative control group was significantly different from that of the autologous lungs, while the transplant lungs in the treatment group were almost identical in color to the autologous lungs compared to the blank control group. Compared with the negative control group, the treatment group showed reduced alveolar exudate and more intact airway epithelial cell structure. No alveolar exudate was observed in the blank control group, and the structure of the airways and alveoli remained normal. The treatment group had lower apoptosis rate of airway epithelial cells, lung tissue wet/dry ratio, and MPO activity compared to the negative control group (all P < 0.05). The levels of IL-6 and TNF-α in the bronchoalveolar lavage fluid of the treatment group were lower than those in the negative control group, while the level of IL-10 was higher than that in the negative control group and the blank control group (all P < 0.05). There were no statistically significant differences in the levels of cytokines in plasma among each group (all P > 0.05). Conclusions UC-MSC may effectively alleviate the severity of primary graft dysfunction in rats by reducing the apoptosis rate of cells in lung tissue and inhibiting inflammatory responses.

Objective To establish a chronic rejection (CR) model of mouse heart transplantation and analyze its characteristics. Methods Allogeneic BALB/c and C57BL/6 mice were used as donor and recipient for heart transplantation, and intraperitoneal injection of cytotoxic T lymphocyte-associated antigen 4-immunoglobulin (CTLA4-Ig) was given 1 and 2 days after surgery. Graft survival time, donor specific antibody (DSA) level, graft pathology and inflammatory cell infiltration were observed. Results In allogeneic transplantation model, graft survival time was prolonged after CTLA4-Ig treatment [(28.2±4.1) d vs. (7.0±0.7) d, P < 0.01]. The level of serum DSA-IgG increased at 2, 3 and 4 weeks after surgery, while the level of DSA-IgM remained unchanged. Myocardial cell injury, inflammatory cell infiltration, interstitial fibrosis and C4d deposition in capillaries were aggravated 3 weeks after operation and worsened 4 weeks after operation. The infiltrated immune cells were mainly macrophages, T cells and plasma cells. Conclusions Mouse allogeneic heart transplantation combined with CTLA4-Ig successfully establishes a CR model, which provides a basis for subsequent studies on the pathogenesis and intervention of CR.