As a pivotal strategy to alleviate the shortage of organ donors, xenotransplantation has achieved remarkable advances in both pre-clinical and clinical studies in recent years, driven by continuous optimization of gene modification techniques and immunosuppressive regimens. Nevertheless, clinical translation still confronts formidable challenges, including rejection and heightened infection risks, which severely compromise long-term graft survival. Consequently, the role of immunosuppressive regimens in xenotransplantation has become increasingly prominent. This article summarizes the mechanisms underlying xenogeneic immune rejection, the latest developments in immunosuppressive regimens, cutting-edge strategies for inducing immune tolerance and the major hurdles facing clinical xenotransplantation. It delves into potential optimization strategies and directions for future clinical research, aiming to offer theoretical insights and practical guidance for the safe and effective application of clinical xenotransplantation.

Objective To introduce the modeling method of pendulum-like modified rat abdominal heart heterotopic transplantation model and evaluate the quality of the model. Methods An operator without transplantation experience performed 15 consecutive models, recorded the time of each step, changes in body weight and modified Stanford scores, and calculated the surgical success rate, postoperative 1-week survival rate and technical success rate. Ultrasound examinations was performed in 1 week postoperatively. Results The times for donor heart acquisition, donor heart processing, recipient preparation and transplantation anastomosis were (14.3±1.4) min, (3.5±0.6) min, (13.6±2.1) min and (38.3±5.2) min respectively. The surgical success rate was 87% (13/15), and the survival rate 1 week after operative was 100% (13/13). The improved Stanford score indicated a technical success rate of 92% (12/13), and the postoperative 1-week ultrasound examination showed that grafts with Stanford scores ≥3 had detectable pulsation and blood flow signals. Conclusions The pendulum-like modified rat abdominal heart heterotopic transplantation improved model further optimizes the operational steps with a high success rate and stable quality, may be chosen as a modeling option for basic research in heart transplantation in the future.

BACKGROUND:At present,there are few reports on the postoperative efficacy of arthroscopic coracoid tunnel-free suspension fixation and coracoid single tunnel fixation in the treatment of acromioclavicular joint dislocation at home and abroad.The specific clinical efficacy of the two procedures and whether there are other risks need to be explored. OBJECTIVE:To compare the short-term postoperative clinical efficacy of arthroscopic TightRope band plate fixation with single tunnel fixation of the coracoid process and tunnel-free suspension fixation of the coracoid process in the treatment of acute type Ⅲ-Ⅴ acromioclavicular joint dislocation. METHODS:A retrospective analysis was performed in 45 patients with acromioclavicular joint dislocation who met the inclusion criteria admitted to the Sixth Affiliated Hospital of Xinjiang Medical University from June 2019 to September 2022,and were divided into coracoid single tunnel fixation group(20 cases)and coracoid tunnel-free suspension fixation group(25 cases)according to the surgical treatment plan.Operation time,incision length,blood loss,Constant-Murley score,visual analogue scale score,the American Shoulder and Elbow Surgeons(ASES)score and intraoperative and postoperative complications of the shoulder joint before operation,3 months after surgery and the last follow-up were compared between the two groups. RESULTS AND CONCLUSION:All patients successfully completed the operation,and there was no important nerve or blood vessel damage during the operation.The operation time of the coracoid tunnel-free suspension fixation group was significantly shorter than that of the coracoid tunnel-free suspension fixation group(P<0.05).There was no significant difference in intraoperative blood loss and incision length between the two groups(P>0.05).All patients were followed up for 12 to 24 months,with an average of(15.29±2.73)months.In the coracoid single tunnel fixation group,at 3 months after operation and the final follow-up,the visual analogue scale score was significantly lower than the preoperative score(P<0.05);Constant-Murley score and ASES score were significantly increased compared with the preoperative values(P<0.05).In the coracoid tunnel-free suspension fixation group,at 3 months after operation and the final follow-up,the visual analogue scale score was significantly lower than the preoperative score(P<0.05);the Constant-Murley score and the ASES score were both significantly higher than the preoperative scores(P<0.05).At 3 months after operation,the Constant-Murley score of the coracoid tunnel-free suspension fixation group was higher than that of the coracoid single tunnel fixation group(P<0.05),while there was no significant difference in visual analogue scale and ASES scores between the two groups(P>0.05).There was also no significant difference in the visual analogue scale,Constant-Murley,and ASES scores between the two groups at the corresponding time points before surgery and at the final follow-up(P>0.05).Intraoperative and postoperative complications:In the coracoid single tunnel fixation group,there was one case of coracoid cortical rupture and fracture during the tunnel drilling during the operation,and one case of a loss of reduction at 3 months after operation,which was repositioned and fixed with hook plate transposition of the coracoacromial ligament.All patients had good acromioclavicular joint function recovery and no re-dislocation at the final follow-up.All patients in the coracoid tunnel-free suspension fixation group did not suffer from coracoid fractures,loss of reduction and other complications during surgery,postoperatively and at the last follow-up.To conclude,these two arthroscopic treatments for acute type Ⅲ-Ⅴ acromioclavicular joint dislocation have the advantages of less trauma,reliable reduction and fixation,and good recovery of shoulder joint function after operation.However,compared with the coracoid single tunnel technique,the coracoid tunnel-free suspension fixation requires shorter time,faster recovery of shoulder joint function in the short term,and avoids the establishment of bone tunnels on the coracoid process,which reduces the probability of iatrogenic fracture of the coracoid process during operation and provides a higher degree of safety.

Xenotransplantation is one of the effective ways to overcome the shortage of donor organs. However, the molecular incompatibility between xenotransplantation donors and recipients can cause rejection, which greatly limits the clinical application of xenotransplantation. In recent years, researchers have deeply explored the mechanism of xenotransplantation rejection through xenotransplantation models of pig-to-monkey and pig-to-brain death recipients, and found that the innate immune system plays an important role in rejection. Macrophages, as phagocytes in the innate immune system, not only damage xenografts through phagocytosis but also interact with other immune cells to influence the immune microenvironment of xenotransplantation. However, due to the heterogeneity of macrophages, their phenotypes and functions in xenotransplantation rejection remain unclear. Therefore, it is necessary to further explore the role of macrophages in xenotransplantation rejection. This article reviews the latest research progress of macrophages in xenotransplantation rejection, aiming to explore the mechanisms of macrophages in xenotransplantation rejection and provide references for future research.

Hypercoagulable state (HCS) after kidney transplantation is one of the common and serious complications in kidney transplant recipients, which has attracted increasing attention in recent years. HCS refers to the abnormal and excessive activation of blood coagulation function, leading to the increased risk of thrombosis. After kidney transplantation, the combined effects of hemodynamic changes, surgical trauma and severe rejection increase the incidence of HCS, not only raising the risk of thrombosis but also potentially causing graft failure and affecting the postoperative survival rate of patients. This article reviews the influencing factors, clinical manifestations, diagnostic methods and preventive strategies of HCS after kidney transplantation, aiming to provide a theoretical basis for optimizing perioperative management and improving the prognosis of patients.

Organ transplantation faces the challenge of a shortage of donors. Although xenotransplantation holds great potential, it is limited by rejection. Extracellular histones, as key members of damage-associated molecular patterns, have been proven in recent years to play a crucial role in transplant rejection by activating innate immunity, regulating the coagulation-inflammation network, and modulating adaptive immune responses. However, the specific functions and key mechanisms remain to be clarified. Therefore, this article reviews the structural characteristics of histones, their release pathways, the biological functions of extracellular histones, and their potential roles in xenotransplantation. It summarizes the latest research progress of extracellular histones in xenotransplantation, analyzes the shortcomings of existing research and the direction for future research, with the expectation of providing references for the application of extracellular histones in xenogeneic kidney transplantation.

Background::Influenza and pneumococcal vaccination are a priority in patients with chronic obstructive pulmonary disease (COPD). However, limited information is available on vaccination coverage among patients with acute exacerbations of COPD (AECOPD) in China. This study aimed to determine the rates and associated factors of influenza and pneumococcal vaccination in patients hospitalized with AECOPD.Methods::Baseline data from a national, multicenter, hospital-based study that included adult inpatients with AECOPD between 2017 and 2021 were analyzed. The outcomes of interest were the influenza vaccination in the past year and the pneumococcal vaccination in the past 5 years. To ensure national representativeness, rates were weighted according to the distribution of hospital levels and types enrolled in this study. Multivariable Poisson regression based on mixed-effects models were used to determine the associated factors. The independent variables included the region and hospital features where the participants were located, sociodemographic characteristics (age, sex, rural/urban residence, education, etc.), and clinical indicators (COPD disease history, lung function parameters, comorbidities, etc.). The treatment profiles of the vaccinated and unvaccinated participants were compared.Results::Of 6949 eligible participants, the weighted rates of influenza/pneumococcal, influenza, and pneumococcal vaccination were 2.72% (95% confidence interval [CI]: 2.34%-3.10%), 2.09% (95% CI: 1.76%-2.43%), and 1.25% (95% CI: 0.99%-1.51%), respectively. In multivariable models, age ≥60 years (60-69 years, odds ratio [OR]: 1.90, 95% CI: 1.11-3.25; ≥80 years, OR: 2.00, 95% CI: 1.06-3.78), geographical regions (Northern China relative to Eastern China, OR: 5.09, 95% CI: 1.96-13.21), urban residence (OR: 1.69, 95% CI: 1.07-2.66), a higher education level (junior high school, OR: 1.77, 95% CI: 1.21-2.58; senior high school or above, OR: 2.61, 95% CI: 1.69-4.03), former smoking (OR: 1.79, 95% CI: 1.15-2.79), and regular inhaled medication treatment (OR: 3.28, 95% CI: 2.29-4.70) were positively associated with vaccination. Patients who had experienced severe exacerbations in the past year were less likely to be vaccinated (OR: 0.65, 95% CI: 0.45-0.96). Compared with unvaccinated participants, vaccinated participants adhered better to pharmacological and non-pharmacological treatment.Conclusions::Influenza and pneumococcal vaccination coverage are extremely low. Urgent measures are necessary to increase vaccination coverage among inpatients with AECOPD in China.

Background::Understanding willingness to undergo pulmonary function tests (PFTs) and the factors associated with poor uptake of PFTs is crucial for improving early detection and treatment of chronic obstructive pulmonary disease (COPD). This study aimed to understand willingness to undergo PFTs among high-risk populations and identify any barriers that may contribute to low uptake of PFTs.Methods::We collected data from participants in the "Happy Breathing Program" in China. Participants who did not follow physicians’ recommendations to undergo PFTs were invited to complete a survey regarding their willingness to undergo PFTs and their reasons for not undergoing PFTs. We estimated the proportion of participants who were willing to undergo PFTs and examined the various reasons for participants to not undergo PFTs. We conducted univariable and multivariable logistic regressions to analyze the impact of individual-level factors on willingness to undergo PFTs.Results::A total of 8475 participants who had completed the survey on willingness to undergo PFTs were included in this study. Out of these participants, 7660 (90.4%) were willing to undergo PFTs. Among those who were willing to undergo PFTs but actually did not, the main reasons for not doing so were geographical inaccessibility ( n = 3304, 43.1%) and a lack of trust in primary healthcare institutions ( n = 2809, 36.7%). Among the 815 participants who were unwilling to undergo PFTs, over half ( n = 447, 54.8%) believed that they did not have health problems and would only consider PFTs when they felt unwell. In the multivariable regression, individuals who were ≤54 years old, residing in rural townships, with a secondary educational level, with medical reimbursement, still working, with occupational exposure to dust, and aware of the abbreviation "COPD" were more willing to undergo PFTs. Conclusions::Willingness to undergo PFTs was high among high-risk populations. Policymakers may consider implementing strategies such as providing financial incentives, promoting education, and establishing community-based programs to enhance the utilization of PFTs.

CD47 is a transmembrane protein widely expressed on cell surface, which is considered as a key molecule for immune escape. With an increasing number of related studies, the role of CD47 and its ligands in immunomodulatory effects has been gradually understood. Recent studies have investigated the role of CD47 in ischemia-reperfusion injury of allogenetic kidney transplantation, rejection and xenotransplantation. Nevertheless, the specific role and the key mechanism remain elusive. In this article, the structure and function of CD47, common CD47 ligands, the relationship between CD47 and kidney transplantation, and the application of CD47 in kidney transplantation were reviewed, the latest research progress of CD47 in kidney transplantation was summarized, and the limitations of current research and subsequent research direction were analyzed, aiming to provide reference for subsequent application of CD47 in allogeneic and kidney xenotransplantation.

Xenotransplantation is an efficient pathway to solve the problem of transplant organ source deficiency in clinical settings. With the increasing progress of gene editing technique and immune suppression regimen, important development has been achieved on researches regarding pig to non-human primate kidney xenotransplantation, which provides a good condition for the introduction of the technique in the clinical application. In view of the substantial difference between human and non-human primate, and to meet the needs of current ethic requirements, it is necessary to perform subclinical studies for pig to human kidney xenotransplantation. In recent years, such subclinical studies with regard to the genetically modified pig to brain death recipient kidney xenotransplantation had been performed, indicating that kidney xenotransplantation gradually began to transit to the clinical development stage. However, donor/recipient selection and immune suppression regimen has not reached a consensus yet, and has to be clarified in subclinical studies. In this article, the current status and confronted problems of donor/recipient selection, immune suppression regimen and post transplantation management in the subclinical studies of kidney xenotransplantation were reviewed, aiming to promote the clinical transformation of kidney xenotransplantation to the clinical application.