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.

Viral infection has always been a significant challenge to human health. Transplant recipients, including those who have undergone solid organ transplantation and allogeneic hematopoietic stem cell transplantation, are at high risk of viral infection due to their weak immune function under immunosuppressive therapy. Unlike the general population, transplant recipients are prone to pneumonia and even severe pneumonia after respiratory viral infection, which requires close attention from clinicians. Therefore, this article reviews the clinical characteristics and special management of viral infection in this population, focusing on the epidemiological features of common respiratory viral infection in transplant recipients, early diagnosis and intervention after infection, severe warning signs and drug treatment strategies, for the reference of clinical colleagues.

Kidney transplant recipient (KTR) faces significant challenges in long-term survival, with the incidence of post-transplant malignancies being 2 to 3 times higher than that of the general population, making it the second leading cause of death in KTR. Immune checkpoint inhibitors (ICI) represent an important breakthrough in malignancy treatment, significantly improving the prognosis of some malignancy patients by blocking co-inhibitory signaling molecules and activating T lymphocyte activity. However, due to concerns about the risk of rejection, solid organ transplant recipients, including KTR, are usually excluded from ICI clinical trials. Existing evidence shows that the incidence of rejection during ICI treatment can be as high as 40%-50%, with the specific mechanisms not yet clear. Therefore, how to enable KTR to effectively benefit from the anti-tumor effects of ICI while avoiding rejection is crucial. This article focuses on the core contradiction of ICI in the treatment of post-transplant malignancies in KTR, that is, the dual effects of activating anti-tumor immunity and inducing transplant kidney rejection. It systematically reviews the current clinical application status and challenges, and explores optimization strategies for the delicate balance between restoring anti-tumor immunity and triggering rejection.

Objective To evaluate clinical efficacy of lung transplantation for lung chronic graft-versus-host disease (cGVHD) after hematopoietic stem cell transplantation (HSCT). Methods Clinical data of 12 patients undergoing lung transplantation for lung cGVHD were retrospectively analyzed. Preoperative clinical manifestations and involved organs of patients were analyzed. The lung function before and after lung transplantation was compared, and the survival of patients after lung transplantation was analyzed. Results Eleven patients underwent HSCT due to primary hematological malignancies, including 9 cases of leukemia, 1 case of myelodysplastic syndrome, 1 case of lymphoma. And 1 case underwent HSCT for systemic lupus erythematosus. Among 12 cGVHD patients, skin involvement was found in 8 cases, oral cavity involvement in 5 cases, gastrointestinal tract involvement in 4 cases and liver involvement in 3 cases. All 12 patients developed severe respiratory failure caused by cGVHD before lung transplantation, including 9 cases of typeⅡ respiratory failure and 3 cases of type Ⅰ respiratory failure. Two patients underwent right lung transplantation, 2 cases of left lung transplantation and 8 cases of bilateral lung transplantation. The interval from HSCT to lung transplantation was 75 (19-187) months. Upon the date of submission, postoperative follow-up time was 18 (7-74) months. Ten patients survived, 1 died from severe hepatitis at postoperative 22 months, and 1 died from gastrointestinal bleeding at postoperative 6 months. No recurrence of primary diseases was reported in surviving patients. Conclusions Lung transplantation is an efficacious treatment for lung cGVHD after HSCT, which may prolong the survival time and improve the quality of life of the recipients.

With the optimization of surgical technologies and postoperative management regimens, the number of lung transplantation has been significantly increased, which has become an important treatment for patients with end-stage lung disease. However, due to the impact of comprehensive factors, such as bronchial ischemia and immunosuppression, the incidence of airway stenosis after lung transplantation is relatively high, which severely affects postoperative survival and quality of life of lung transplant recipients. In recent years, with the improvement of perioperative management, organ preservation and surgical technologies, the incidence of airway stenosis after lung transplantation has been declined, but it remains at a high level. Early diagnosis and timely intervention play a significant role in enhancing clinical prognosis of patients with airway stenosis. In this article, the general conditions, diagnosis, treatment and prevention of airway stenosis after lung transplantation were reviewed, aiming to provide reference for comprehensive management of airway stenosis after lung transplantation and improving clinical prognosis of lung transplant recipients.

Nocardiosis is a collective term for tissue and organ damage caused by Nocardia infection.Solid organ transplant recipients(SOTR)are at an increased risk of various pathogen infections,including Nocardia infection,due to immunosuppressive therapy which weakens their immune function.The diagnosis of nocardiosis has been challenging in the past.With the advent of molecular biology and other diagnostic methods,the diagnostic rate has significantly improved.Nocardia not only prone to cause necrotic pulmonary lesions but also invade other organs and tissues,such as intracranial infections and skin soft tissue infections,and can develop into systemic disseminated infections.For SOTR,nocardiosis is a potentially fatal disease with a fatality as high as 30%.Therefore,this article reviews the clinical characteristics of common nocardiosis in SOTR,new diagnostic technologies,and different anti-infective treatment strategies,aiming to provide a reference for the prevention and treatment of nocardiosis in clinical SOTR.

Long-term use of immunosuppressants result in an immunocompromised state, repeated hospitalizations and dosing of broad-spectrum antibiotics. Presence of transplant-associated diabetes and cadaveric donations are contributing factors to a higher risk of invasive fungal disease (IFD ) among solid organ transplantation (SOT) recipients. Furthermore, the epidemiology of IFD in SOT recipients has continuously evolved in recent years. Understanding the current epidemiological status of IFD in SOT recipients, becoming familiar with new diagnostic technologies for IFD and mastering the characteristics of novel antifungal medications may further improve the prognosis for recipients. This review summarized the incidence, pathogen composition, new diagnostic technologies and recently marketed novel antifungal medications for IFD in SOT recipients, aiming to offer references for clinical practices.

Objective:Analysis of surgical strategies for atrial functional mitral regurgitation with atrial fibrillation.Methods:Retrospective analysis of 112 patients with mitral regurgitation and atrial fibrillation between June 2017 and January 2023. Among them, 56 cases were severe atrial functional mitral regurgitation with atrial fibrillation, and the other 56 cases were degenerative mitral regurgitation with atrial fibrillation. All patients underwent maze Ⅳ procedure and mitral valve surgery. Follow up will be conducted through outpatient follow-up and telephone calls. The condition of postoperative mitral valve is obtained through echo. The postoperative cardiac rhythm is based on the patient's conscious symptoms, electrocardiogram, 24 hour dynamic electrocardiogram.Results:The comparison of preoperative basic data shows that the age, duration of atrial fibrillation, and comorbidity of patients with atrial functional mitral regurgitation are significantly higher than those in the degenerative mitral regurgitation group. All patients successfully completed the surgery. Postoperative death occurred in 2 cases in the atrial mitral regurgitation group. The causes of death were ARDS and pulmonary infection, respectively. The main postoperative complications include bleeding, low cardiac output, pulmonary infection, and acute kidney injury. During follow-up, 43 patients (79.6%) in the atrial mitral regurgitation group maintained sinus rhythm, while 49 patients (87.5%) in the degenerative group. However, there was no statistically significant difference in the Kaplan- Meier curves. In the atrial mitral regurgitation group, there were 47 cases with no mitral regurgitation, 4 cases with mild regurgitation, and 1 case with moderate regurgitation. In the degenerative group, there were 42 cases with no mitral regurgitation, 6 cases with mild regurgitation, 1 case with moderate regurgitation, and 1 case with severe regurgitation. The risk for atrial fibrillation recurrence in the atrial mitral regurgitation is related to postoperative left atrial diameter greater than 50 mm, while in the degenerative group, atrial fibrillation recurrence is related to postoperative left atrial diameter greater than 50 mm and residual mitral regurgitation. Conclusion:Mitral valve repair combined with maze Ⅳ procedure is an effective treatment for patients with severe atrial functional mitral regurgitation and atrial fibrillation. Further improving the success rate of atrial fibrillation and reducing surgical trauma will benefit patients in the future.

Due to long-term use of immunosuppressive agents, solid organ transplant recipients (SOTR) belong to high-risk populations of multiple pathogenic infection, including SARS-CoV-2. In addition, SOTR are constantly complicated by chronic diseases, such as hypertension and diabetes mellitus, etc. After infected with SARS-CoV-2, the critically ill rate and fatality of SOTR are higher than those of the general population, which captivates widespread attention from experts in the field of organ transplantation. Omicrone variant is currently the significant pandemic strain worldwide, rapidly spreading to more than 100 countries worldwide and causing broad concern. According to the latest international guidelines on the diagnosis and treatment of SARS-CoV-2 infection and relevant expert consensus in China combined with current domestic situation of SARS-CoV-2 pandemic and China's "diagnosis and treatment regimen for SARS-CoV-2 infection (Trial Version 10)", the epidemiology, clinical manifestations and prognosis, diagnosis, clinical classification and treatment of SARS-CoV-2 infection were briefly reviewed.

Objective To analyze the changes of postoperative pulmonary function in lung transplant recipients. Methods Clinical data of 81 recipients undergoing bilateral lung transplantation and combined heart-lung transplantation were collected, and postoperative status of the recipients was analyzed. Pulmonary ventilation and diffusion function indexes at 1 month, 3 months, every 3 months (3-18 months after lung transplantation) and every 6 months (18-36 months after lung transplantation) were analyzed in the recipients. The characteristics of the optimal pulmonary function in the recipients were assessed. Results Postoperative mechanical ventilation time was 4 (2, 9) d, and the length of postoperative ICU stay was 10 (7, 20) d. Among 81 recipients, 27 recipients developed primary graft dysfunction (PGD) after lung transplantation, with an incidence rate of 33%. Postoperative forced vital capacity (FVC) to predicted value ratio (FVC%pred), forced expiratory volume in one second (FEV₁) to predicted value ratio (FEV₁%pred), FEV₁/FVC to predicted value ratio (FEV₁/FVC%pred) and corrected diffusion lung capacity for CO to predicted value ratio (D_LCOc%pred) were changed over time (all P<0.001). FVC%pred and FEV₁%pred were gradually increased within postoperative 9 months, and D_LCOc%pred was gradually elevated within postoperative 3 months (all P<0.05). Thirty-six recipients had FVC%pred≥80%, FEV₁%pred≥80% in 41 cases, FEV₁/FVC%pred≥92% in 76 cases, FVC%pred≤40% in 1 case and FEV₁%pred≤40% in 1 case, respectively. Sixteen recipients had D_LCOc%pred≥80%, corrected diffusion lung capacity for CO/alveolar volume to predicted value ratio (D_LCOc/V_A%pred) ≥80% in 63 cases, D_LCOc%pred≤40% in 4 cases and D_LCOc/V_A%pred≤40% in 1 case, respectively. Postoperative FVC%pred, FEV₁/FVC%pred and D_LCOc%pred in recipients with a primary disease of obstructive pulmonary disease were significantly higher than those in their counterparts with restrictive pulmonary disease (all P<0.05). Postoperative D_LCOc%pred in recipients with PGD was significantly lower than that in those without PGD (P<0.05). Conclusions Pulmonary ventilation function in lung transplant recipients reaches the optimal state and maintains a steady state at postoperative 9 months, and pulmonary diffusion function reaches a steady state at postoperative 3 months. Primary diseases and the incidence of PGD may affect postoperative pulmonary function.