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.

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.

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.

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.

This article summarizes the new progress in the diagnosis and treatment strategies on drug-resistant cytomegalovirus(CMV)infections in organ transplant recipients, including the prevention and treatment medications for CMV infection, the diagnosis and treatment strategies, and the immunological treatment regimen for drug-resistant CMV infection.The article is aimed to provide references for the prevention and treatment of drug-resistant CMV infection in organ transplant recipients.

Since an outbreak of coronavirus disease 2019, there have been more than 664 million confirmed cases and more than 6.7 million deaths worldwide.The Omicron variant discovered in November 2021 has become a dominant variant in China.Compared with the general population, Omicron infection mainly presents short-term upper respiratory symptoms followed by quick recovery; solid organ transplant recipients have the characteristics of a high incidence of severe disease and high mortality after infection, and the incidence of secondary infection and rebound positivity is significantly higher than that of the general population.This review focused upon preventive strategies of solid organ transplant recipients from the perspectives of the characteristics of organ transplant recipients, general preventive strategies, vaccination and long-acting neutralizing antibodies.

Objective:To study the influence of Mei mini maze procedure for atrial functional mitral regurgitation.Methods:The data of 33 patients with atrial fibrillation and atrial functional mitral regurgitation from January 2017 to June 2020 were retrospectively analyzed. All patients received Mei mini maze procedure for atrial fibrillation. The procedure is carried out thoracoscopically through the left thoracic approach. The ablation of atrial fibrillation includes bilateral circumferential pulmonary vein ablation, isolation of the left atrium posterior wall, left atrial appendage resection, ablation of Marshall's ligament and autonomic ganglion, etc. Follow-up was conducted by outpatient follow-up and telephone. Postoperative heart rhythm was recorded by the patient's symptoms, electrocardiogram, 24 h holter and other examinations. Postoperative mitral valve lesions were obtained by echocardiography.Results:33 patients successfully completed the operation. There was no conversion to thoracotomy and no perioperative death. Thirty patients(90.9%) maintained sinus rhythm at discharge. Before discharge, 16 patients had no mitral regurgitation in echocardiography, 8 patients had mild mitral regurgitation, and 9 patients had moderate mitral regurgitation. Follow-up was 1-4 years after discharge, with a mean of(2.6±1.1) years. Sinus rhythm was maintained in 23 patients(69.7%). 17 patients had no mitral regurgitation, 9 had mild mitral regurgitation, 6 had moderate, and 1 had severe mitral regurgitation. The degree of regurgitation in 25 patients was reduced compared with pre-operation, 5 patients remained unchanged, and 3 patients mitral regurgitation aggravated. Unreduced atrial functional mitral regurgitation was associated with recurrence of atrial fibrillation by Cox multivariate analysis.Conclusion:This study found a close relationship between atrial fibrillation rhythm and atrial functional mitral regurgitation. Most moderate atrial functional mitral regurgitation can be alleviated by effective treatment for atrial fibrillation. It is not recommended that patients with severe atrial functional mitral regurgitation only receive treatment for atrial fibrillation.