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 explore the clinical characteristics of Mycoplasma pneumoniae pneumonia(MPP)after COVID-19 epidemic so as to offer help for early clinical diagnosis and treatment.METHODS The clinical data that were collected from the MPP patients who were treated in the fever clinic of the First Medical Center of Chinese PLA General Hospital from Jul.2023 to Aug.2024 were retrospectively analyzed.The results of laboratory tests for the different age groups of patients complicated with other pathogens were statistically analyzed.RESULTS Of totally 161 MPP patients who were enrolled in the study,78(48.85％)were male,and 83(51.55％)were fe-male;the average age was(32.98±14.35)years old,and the patients aged between 20 and 40 years old accoun-ted for 43.48％(70 cases).The enrolled patients were divided into the simple MPP group with 92(57.14％)ca-ses and the MPP+mixed group with 69(42.86％)cases according to the result of etiological test of sputum;the patients of MPP+mixed group were divided into the MPP+bacteria group with 42(60.87％)cases,the MPP+fungi group with 10(14.49％)cases,and the MPP+viruses group with 17(24.64％)cases.There was significant difference in the age among the groups(P＜0.05);there were no significant differences in the sex,white blood cell counts and percentage of mononuclear cells among the groups,the percentage of lymphocytes was highest in the simple MPP group,the levels of C-reactive protein(CRP)and interleukin-6(IL-6)were highest in the MPP+bacteria group,and there were significant differences(P＜0.05).All of the patients were divided into three groups:the ≤20-year-old group the＞20-40-year old group and the＞40-year-old group.There were no sig-nificant differences in the white blood cell counts,percentage of lymphocytes,percentage of mononuclear cells and IL-6 level among the three groups,and the CRP level was highest in the＞20-40-year old group(P=0.025).Ran-dom forest model analysis showed that the weight of CRP was highest(22.65％)among the clinical characteristics of the MPP patients,which played a key role in construction of model.As for other factors,the weight of age was 17.02％,the percentage of lymphocytes 15.34％,the white blood cells counts 14.86％,the percentage of mono-nuclear cells 14.39％,the IL-6 13.61％,the gender 2.13％.CONCLUSION MPP maintains common among the patients aged less than 40 years old after the COVID-19 epidemic,nearly half of the patients are complicated with the infections of other pathogens,and CRP is more helpful for the clinical diagnosis and treatment of the MPP in early stage.

OBJECTIVE To summarize the clinical characteristics and diagnosis and treatment experiences in dealing with non-severe Chlamydia psittaci pneumonia.METHODS The clinical data were collected from 34 patients who were diagnosed with non-severe C.psittaci pneumonia through quantitative polymerase chain reactiong(qPCR)for sputum in fever clinic of the First Medical Center of Chinese PLA General Hospital from Mar.2023 to Mar.2024 and were retrospectively analyzed.The clinical characteristics and treatment outcomes were evaluated.RESULTS The average age of the patients was(44.82±13.74)years old,the ratio of male to female was 1∶1.83;all of the patients had fever;major symptoms were cough(70.59％),pharyngodynia(44.12％),and flu-like symptoms(41.18％);82.35％of the patients had the history of contact with poultry.The C-reactive pro-tein(CRP)level,interleukin-6(IL-6),systemic inflammatory response index(SIRI)and aggregate index of sys-temic inflammation(AISI)were higher among the patients aged no less than 44 years old than among the patients less than 44 years old(P＜0.05);the percentage of lymphocytes of the patients aged no less than 44 years old was lower than that of the patients aged less than 44 years old(P＜0.05).As for the imaging findings,73.53％of the patients had consolidation shadows,26.47％had ground-glass opacities,and 32.35％involved both lungs.All of the patients received quinolones or tetracyclines for treatment of 7-14 days and all symptoms relieved.CT reexami-nated 1 month after the treatment showed that 55.88％of the cases had complete absorption of pulmonary infec-tious lesions,and 35.29％had partial absorption.CONCLUSIONS The patients with non-severe Chlamydia psitta-ci pneumonia are characterized by the history of contact with poultry,fever complicated with respiratory tract symptoms,rise of inflammatory markers(more significant among patients of advanced age)and lower lobe con-solidation shadow/ground-glass opacities.Early identification and standardized treatment may facilitate the favora-ble treatment outcomes.

Talaromyces marneffei is a rare opportunistic pathogen.Talaromyces marneffei infection is characterized by insidious onset,atypical clinical manifestations,low early diagnosis rate,and high misdiagnosis and fatality,and has received widespread attention in recent years.Organ transplant recipients become a high-risk group for Talaromyces marneffei infection due to postoperative immunosuppressive therapy.Metagenomic next-generation sequencing,targeted antifungal therapy,and immunosuppression regimen adjustment are key to improving the prognosis of Talaromyces marneffei infection patients.This article reviews the epidemiology,pathogenesis,diagnosis and treatment of Talaromyces marneffei infection in organ transplant recipients,explores current challenges and future research directions,and aims to inform the diagnosis and treatment of Talaromyces marneffeiinfection.

OBJECTIVE To explore the clinical characteristics of Mycoplasma pneumoniae pneumonia(MPP)after COVID-19 epidemic so as to offer help for early clinical diagnosis and treatment.METHODS The clinical data that were collected from the MPP patients who were treated in the fever clinic of the First Medical Center of Chinese PLA General Hospital from Jul.2023 to Aug.2024 were retrospectively analyzed.The results of laboratory tests for the different age groups of patients complicated with other pathogens were statistically analyzed.RESULTS Of totally 161 MPP patients who were enrolled in the study,78(48.85％)were male,and 83(51.55％)were fe-male;the average age was(32.98±14.35)years old,and the patients aged between 20 and 40 years old accoun-ted for 43.48％(70 cases).The enrolled patients were divided into the simple MPP group with 92(57.14％)ca-ses and the MPP+mixed group with 69(42.86％)cases according to the result of etiological test of sputum;the patients of MPP+mixed group were divided into the MPP+bacteria group with 42(60.87％)cases,the MPP+fungi group with 10(14.49％)cases,and the MPP+viruses group with 17(24.64％)cases.There was significant difference in the age among the groups(P＜0.05);there were no significant differences in the sex,white blood cell counts and percentage of mononuclear cells among the groups,the percentage of lymphocytes was highest in the simple MPP group,the levels of C-reactive protein(CRP)and interleukin-6(IL-6)were highest in the MPP+bacteria group,and there were significant differences(P＜0.05).All of the patients were divided into three groups:the ≤20-year-old group the＞20-40-year old group and the＞40-year-old group.There were no sig-nificant differences in the white blood cell counts,percentage of lymphocytes,percentage of mononuclear cells and IL-6 level among the three groups,and the CRP level was highest in the＞20-40-year old group(P=0.025).Ran-dom forest model analysis showed that the weight of CRP was highest(22.65％)among the clinical characteristics of the MPP patients,which played a key role in construction of model.As for other factors,the weight of age was 17.02％,the percentage of lymphocytes 15.34％,the white blood cells counts 14.86％,the percentage of mono-nuclear cells 14.39％,the IL-6 13.61％,the gender 2.13％.CONCLUSION MPP maintains common among the patients aged less than 40 years old after the COVID-19 epidemic,nearly half of the patients are complicated with the infections of other pathogens,and CRP is more helpful for the clinical diagnosis and treatment of the MPP in early stage.

OBJECTIVE To summarize the clinical characteristics and diagnosis and treatment experiences in dealing with non-severe Chlamydia psittaci pneumonia.METHODS The clinical data were collected from 34 patients who were diagnosed with non-severe C.psittaci pneumonia through quantitative polymerase chain reactiong(qPCR)for sputum in fever clinic of the First Medical Center of Chinese PLA General Hospital from Mar.2023 to Mar.2024 and were retrospectively analyzed.The clinical characteristics and treatment outcomes were evaluated.RESULTS The average age of the patients was(44.82±13.74)years old,the ratio of male to female was 1∶1.83;all of the patients had fever;major symptoms were cough(70.59％),pharyngodynia(44.12％),and flu-like symptoms(41.18％);82.35％of the patients had the history of contact with poultry.The C-reactive pro-tein(CRP)level,interleukin-6(IL-6),systemic inflammatory response index(SIRI)and aggregate index of sys-temic inflammation(AISI)were higher among the patients aged no less than 44 years old than among the patients less than 44 years old(P＜0.05);the percentage of lymphocytes of the patients aged no less than 44 years old was lower than that of the patients aged less than 44 years old(P＜0.05).As for the imaging findings,73.53％of the patients had consolidation shadows,26.47％had ground-glass opacities,and 32.35％involved both lungs.All of the patients received quinolones or tetracyclines for treatment of 7-14 days and all symptoms relieved.CT reexami-nated 1 month after the treatment showed that 55.88％of the cases had complete absorption of pulmonary infec-tious lesions,and 35.29％had partial absorption.CONCLUSIONS The patients with non-severe Chlamydia psitta-ci pneumonia are characterized by the history of contact with poultry,fever complicated with respiratory tract symptoms,rise of inflammatory markers(more significant among patients of advanced age)and lower lobe con-solidation shadow/ground-glass opacities.Early identification and standardized treatment may facilitate the favora-ble treatment outcomes.

Talaromyces marneffei is a rare opportunistic pathogen.Talaromyces marneffei infection is characterized by insidious onset,atypical clinical manifestations,low early diagnosis rate,and high misdiagnosis and fatality,and has received widespread attention in recent years.Organ transplant recipients become a high-risk group for Talaromyces marneffei infection due to postoperative immunosuppressive therapy.Metagenomic next-generation sequencing,targeted antifungal therapy,and immunosuppression regimen adjustment are key to improving the prognosis of Talaromyces marneffei infection patients.This article reviews the epidemiology,pathogenesis,diagnosis and treatment of Talaromyces marneffei infection in organ transplant recipients,explores current challenges and future research directions,and aims to inform the diagnosis and treatment of Talaromyces marneffeiinfection.

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.

Hepatocellular carcinoma （HCC） with biliary duct tumor thrombus （BDTT） is currently not common in clinical practice and is easily misdiagnosed， and previously， it was often considered an advanced stage of the disease with a poor prognosis， making its treatment challenging. However， in-depth studies in recent years have gradually deepened our understanding of this disease， leading to significant changes in diagnostic and treatment concepts. Currently， comprehensive treatment， mainly surgery， is used for treatment， but there is still controversy over the selection of clinical treatment strategies. This article provides a detailed discussion on surgical methods and prognosis， in order to provide a reference for clinical treatment options.

Objective To understand the clinical distribution characteristics and drug-resistance genotypes of carbapenem-resistant Pseudomonas aeruginosa(CRPA)in a tertiary hospital in Shanghai,so as to guide the rational use of antibiotics,reduce bacterial resistance and control nosocomial infections.Methods A total of 94 consecutive and non-redundant CRPA strains isolated from clinical specimens were collected in The First Affiliated Hospital of Naval Medical University between Jan.1,and Dec.31,2019.The distribution of CRPA across departments and sample sources were analyzed.Antimicrobial susceptibility testing against 13 antibiotics was determined using the VITEK 2 Compact automated microbiology analyzer and the Kirby-Bauer disk diffusion method.Polymerase chain reaction(PCR)was employed to detect genes encoding extended-spectrum β-lactamase resistance gene,carbapenemase resistance gene,and porin resistance gene.Homology analysis of selected isolates was performed using kSNP3,a k-mer-based software,for single nucleotide polymorphism(SNP)analysis.An evolutionary tree was constructed to assess genetic relationships.Additionally,multilocus sequence typing(MLST)was performed using the Pseudomonas aeruginosa typing scheme from the PubMLST database.Results Among the 94 CRPA isolates,high resistance rates were observed for carbapenems,including imipenem(92.6%,87 strains)and meropenem(87.2%,82 strains).In contrast,low resistance rates were detected for aminoglycosides,such as amikacin(10.6%,10 strains),gentamicin(20.2%,19 strains),and tobramycin(20.2%,19 strains).The top 3 departments in terms of isolate distribution were the Emergency Intensive Care Unit(9.6%,9 strains),Department of Cerebrovascular Surgery(8.5%,8 strains),and Department of Respiratory Medicine(8.5%,8 strains).PCR analysis of 94 CRPA strains detected outer membrane protein D2(OprD2)gene deletion in 47(50.0%)strains,13(13.8%)strains were positive for blaKPC,4(4.3%)strains for blaVIM,2(2.1%)strains for blaIMP,1(1.1%)strain for blaNDM,12(12.8%)strains for blaTEM,4(4.3%)strains for blaPER,and 2(2.1%)strains for blaGES,while blaOXA-48,blaBIC,blaSIM,blaVEB,and blaSHV were not detected.MLST identified 36 different sequence types(STs),with ST463 and ST274 being the most common,and 2 new ST(ST4023 and ST4024)were identified for the first time.Conclusion CRPA strains carry multiple resistance genes and exhibit concurrent resistance to several commonly used clinical antibiotics.The resistance is primarily associated with the presence of blaKPC,blaVIM and blaTEM genes and the deletion of OprD2 gene.Clinical monitoring of CRPA should be strengthened,and rational use of antimicrobial agents is essential to control its spread within the hospital.