In recent years， mesenchymal stem cells （MSC） have been widely explored in the treatment of liver diseases due to their characteristics of multipotential differentiation and immunomodulatory capabilities. Current evidence has shown that MSC therapy can improve liver function， alleviate fibrosis， and promote hepatocyte regeneration in end-stage liver diseases such as liver cirrhosis and liver failure. However， safety concerns have emerged with the increasing clinical use of MSC. This article systematically reviews the acute adverse reactions and long-term safety of MSC-based therapies for liver diseases. It is shown that MSC therapy has a good overall safety profile， with common acute adverse reactions of fever， rash， and mild allergy， most of which are self-limiting or can be alleviated by symptomatic treatment. No clear evidence of tumorigenesis has been reported in long-term follow-up， but some studies have suggested a potential association between MSC and the development of hepatocellular carcinoma. In addition， the risks of embolism， immune rejection， and infection susceptibility should be monitored continuously. Overall， MSC therapy shows good prospects in short-term efficacy and safety in the treatment of liver diseases， but clinical studies with a large sample size and a long follow-up period are needed to further validate its long-term safety and efficacy.

Objective:To analyze the epidemiological and clinical characteristics of respiratory pathogens in China.Methods:This study was a cross-sectional study, which encompassed 19 core units of the clinical pathogen network and established a three-tiered clinical pathogen surveillance system. Thirty respiratory samples were collected every two weeks from various units from January to December 2024, and the clinical and pathogen diagnostic information were gathered. A total of 11 864 samples were tested using this system. The tier-1 clinical pathogen surveillance system covered influenza A virus (Flu-A), influenza B virus (Flu-B), respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The tier-2 clinical pathogen surveillance system focused on 18 key respiratory pathogens. The tier-3 clinical pathogen surveillance system further clarified whether any emerging infectious diseases had occurred.Results:The tier-1 clinical pathogen surveillance system showed Flu-A predominated in December, Flu-B predominated in January, SARS-CoV-2 peaked in March and August, whereas RSV circulated sporadically throughout the year. Geographic trends were broadly consistent across the seven major regions, although Flu-A detection in December was notably higher in Northeast China (48.1%(111/231)) and East China (36.2%(148/409)), and RSV detection was concentrated in the Northwest and South China from January to March. Data from the tier-2 clinical pathogen surveillance system indicated that Streptococcus pneumoniae, Mycoplasma pneumoniae, rhinovirus, and adenovirus were detected year-round, of these, Streptococcus pneumoniae and rhinovirus showed elevated positive detection rates from August to September, while adenovirus peaked in January. Legionella pneumophila was not detected throughout the year, and other pathogens fluctuated throughout the year without a consistent pattern. The predominant etiologic agents of pediatric pneumonia were Mycoplasma pneumoniae (35.0%(105/300)), rhinovirus (25.7%(77/300)), and adenovirus (17.3%(52/300)), whereas adult pneumonia was mainly caused by Streptococcus pneumoniae (10.5%(29/277)), Staphylococcus aureus (6.9%(19/277)), Mycoplasma pneumoniae (6.9%(19/277)), and Flu-A (6.1%(17/277)). The tier-3 clinical pathogen surveillance system did not identify any emerging respiratory pathogens. Conclusion:Respiratory pathogens in China in 2024 exhibit distinct temporal and spatial distribution patterns and vary among different populations.

Mesenchymal stem cells （MSCs） have emerged as a promising cellular therapy for end-stage liver disease （ESLD） due to their robust self-regenerative， paracrine， and immunomodulatory characteristics， providing new directions for the treatment of advanced liver disease. However， the clinical application of MSCs is significantly limited by the fact that only a small number of MSCs can reach the liver due to massive apoptosis or necrosis during the homing process caused by the influence of the complex microenvironment （inflammation， oxidative stress， and hypoxia） of the injured liver and the fact that a substantial proportion of MSCs become trapped in the pulmonary capillaries following intravenous administration with a lack of sufficient homing receptors or adhesion molecules. Various strategies have been developed to optimize the proliferation， migration， and homing abilities of MSCs， including preconditioning， gene modification， and nanoencapsulation technology. This article elaborates on the influencing factors for the homing ability of MSCs， the strategies to optimize their homing in ESLD， and the mechanism of the homing of MSCs， in order to improve cell transplantation efficiency， promote liver repair and regeneration， and pave the way for the application of MSCs in the treatment of ESLD.

Hepatitis B virus infection is a global public health issue, and there exist many controversies about the antiviral treatment strategies for patients with low-level hepatitis B surface antigen. This article reviews the definition, clinical significance, and current controversial focus of treatment strategies for low-level hepatitis B surface antigen, including treatment timing, drug selection, treatment course determination, and other aspects, while also suggesting future research directions.

Objective:To analyze the epidemiological and clinical characteristics of respiratory pathogens in China.Methods:This study was a cross-sectional study, which encompassed 19 core units of the clinical pathogen network and established a three-tiered clinical pathogen surveillance system. Thirty respiratory samples were collected every two weeks from various units from January to December 2024, and the clinical and pathogen diagnostic information were gathered. A total of 11 864 samples were tested using this system. The tier-1 clinical pathogen surveillance system covered influenza A virus (Flu-A), influenza B virus (Flu-B), respiratory syncytial virus (RSV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The tier-2 clinical pathogen surveillance system focused on 18 key respiratory pathogens. The tier-3 clinical pathogen surveillance system further clarified whether any emerging infectious diseases had occurred.Results:The tier-1 clinical pathogen surveillance system showed Flu-A predominated in December, Flu-B predominated in January, SARS-CoV-2 peaked in March and August, whereas RSV circulated sporadically throughout the year. Geographic trends were broadly consistent across the seven major regions, although Flu-A detection in December was notably higher in Northeast China (48.1%(111/231)) and East China (36.2%(148/409)), and RSV detection was concentrated in the Northwest and South China from January to March. Data from the tier-2 clinical pathogen surveillance system indicated that Streptococcus pneumoniae, Mycoplasma pneumoniae, rhinovirus, and adenovirus were detected year-round, of these, Streptococcus pneumoniae and rhinovirus showed elevated positive detection rates from August to September, while adenovirus peaked in January. Legionella pneumophila was not detected throughout the year, and other pathogens fluctuated throughout the year without a consistent pattern. The predominant etiologic agents of pediatric pneumonia were Mycoplasma pneumoniae (35.0%(105/300)), rhinovirus (25.7%(77/300)), and adenovirus (17.3%(52/300)), whereas adult pneumonia was mainly caused by Streptococcus pneumoniae (10.5%(29/277)), Staphylococcus aureus (6.9%(19/277)), Mycoplasma pneumoniae (6.9%(19/277)), and Flu-A (6.1%(17/277)). The tier-3 clinical pathogen surveillance system did not identify any emerging respiratory pathogens. Conclusion:Respiratory pathogens in China in 2024 exhibit distinct temporal and spatial distribution patterns and vary among different populations.

Hepatitis B virus infection is a global public health issue, and there exist many controversies about the antiviral treatment strategies for patients with low-level hepatitis B surface antigen. This article reviews the definition, clinical significance, and current controversial focus of treatment strategies for low-level hepatitis B surface antigen, including treatment timing, drug selection, treatment course determination, and other aspects, while also suggesting future research directions.

OBJECTIVE:To evaluate the efficacy of exosomes derived from mesenchymal stem cells on animal models of acute liver failure. METHODS:PubMed,Web of Science,Embase,The Cochrane Library,CBM,CNKI,WanFang,and VIP databases were retrieved from inception to January 16,2023.A series of animal experiments on the treatment of acute liver failure animal models by exosomes derived from mesenchymal stem cells were collected.Two evaluators screened the literature and extracted the data independently.The bias risk was evaluated by the SYRCLE tool.The extracted data were analyzed by Revmen 5.4.1 software and Stata 17.0 software. RESULTS:A total of 241 articles were retrieved and 9 animal experiments were included,with 219 animals:110 animals in the model group and 109 animals in the exosome group.The results showed that the survival rate of animals in the exosome group improved significantly[RR=9.34,95%CI(3.91,22.29),P<0.001],the levels of serum alanine transaminase[SMD=-5.31,95%CI(-7.43,-3.19),P<0.001]and aspartate aminotransferase[SMD=-4.47,95%CI(-5.85,-3.10),P<0.001]were reduced obviously.The expressions of interleukin-1β[SMD=-11.54,95%CI(-18.12,-4.95),P=0.000 6],interleukin-6[SMD=-5.75,95%CI(-8.08,-3.41),P<0.001]and tumor necrosis factor-α[SMD=-4.46,95%CI(-6.83,-2.09),P=0.000 2],were suppressed obviously. CONCLUSION:Exosomes derived from mesenchymal stem cells effectively inhibit the inflammatory response,ameliorate liver function of animals with acute liver failure,and improve their survival rate.The results of subgroup analysis showed that the shorter survival time of animals(≤24 hours),the lower dose of transplanted exosomes(<1 mg/kg)and the source of exosomes(adipose-derived mesenchymal stem cells)may affect the efficacy of the exosomes derived from mesenchymal stem cells in the animal model of acute liver failure.This conclusion and its clinical transformation still need to be confirmed by randomized controlled studies with large sample sizes and high quality.

The prognosis of patients with hepatitis C virus infection depends not only on liver lesions， but also on extrahepatic sequelae. Direct-acting antiviral agents （DAAs）， as the first-line drugs in the treatment of hepatitis C， have helped more and more patients achieve sustained virologic response and clinical cure， but its effect on the prognosis of extrahepatic diseases remains unclear. This article reviews the effect of DAAs treatment on the prognosis of extrahepatic diseases in patients with hepatitis C and points out that long-term follow-up monitoring is still required for patients with hepatitis C after cure.

Objective:To analyze the characteristics of chronic hepatitis B (CHB) patients clinically cured, and to explore the advantageous population and regimen of pegylated interferon-α-2b (Peg-IFN-α-2b) treatment.Methods:A total of 188 CHB patients who were treated with Peg-IFN-α-2b in the Department of Infectious Diseases of the First Hospital of Shanxi Medical University from February 2018 to January 2024 and enrolled in the "China research (Oasis) project on reducing the incidence of hepatocellular carcinoma in hepatitis B patients" in Shanxi Province from September 2020 to January 2024 with clinically cured by Peg-IFN-α-2b therapy were selected as subjects. The basic information and efficacy indicators of patients were collected and analyzed, and the levels of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (HBsAb) at baseline, 12 weeks, 24 weeks, 36 weeks, 48 weeks, 72 weeks and 96 weeks of treatment were counted. Patients were divided into negative conversion group and non-negative conversion group according to the status of HBsAg at week 48, and HBsAg levels were compared between the two groups at 12 weeks of treatment. Patients were grouped according to the treatment plan and treatment duration, and the proportions of patients who achieved clinical cure at each monitoring point were compared between groups of sequential combination therapy of nucleo(s)tide analogues (NAs) with Peg-IFN-α-2b and Peg-IFN-α-2b alone, among groups of patients with combination treatment of NAs<5 years, 5 to <10 years and ≥10 years, and among groups of patients with NAs treatment duration <5 years, 5 to <10 years and ≥10 years before the application of Peg-IFN-α-2b. Statistical analysis was performed using chi-square test or Mann-Whitney U test. Results:The age of 188 patients was (43.7±9.9) years old, including 126 males (67.02%) and 62 females (32.98%). There were 150 patients (79.79%) treated with sequential combination therapy of NAs with Peg-IFN-α-2b, and 38 patients (20.21%) treated with Peg-IFN-α-2b alone. The baseline HBsAg level of 188 patients was 51.99(3.26, 250.00) IU/mL, and there were 169 cases (89.89%) with negative hepatitis B e antigen (HBeAg). There were 93 patients (49.47%) with HBsAg <50 IU/mL and 162 cases (86.17%) with negative hepatitis B virus (HBV) DNA at baseline. After 12 weeks, 24 weeks, 36 weeks, 48 weeks, 72 weeks and 96 weeks of treatment, there were 47 cases (25.00%), 47 cases (25.00%), 41 cases (21.81%), 35 cases (18.61%), 14 cases (7.45%) and four cases (2.13%) of HBsAg loss, respectively, and there were 28 cases (14.89%), 33 cases (17.55%), 35 cases (18.62%), 24 cases (12.77%), nine cases (4.79%) and four cases (2.13%) of HBsAg seroconversion, respectively. The levels of HBsAb were 0.63(0.20, 2.08) IU/mL, 3.69(0.68, 19.00) IU/mL, 8.47(1.43, 54.98) IU/mL, 10.96(2.93, 63.42) IU/mL, 15.55(1.10, 82.17) IU/mL and 23.45(2.30, 129.50) IU/mL, respectively. The HBsAg levels at week 12 in the HBsAg negative group (170 cases) and the non-negative group (18 cases) according to the status of HBsAg at week 48 were 0.67(0.03, 36.09) IU/mL and 18.31(5.99, 162.19) IU/mL, respectively. The difference was statistically significant ( Z=2.71, P=0.007). There was no significant difference in the proportion of patients who achieved clinical cure at each monitoring point between patients treated with NAs sequential combined with Peg-IFN-α-2b and patients treated with Peg-IFN-α-2b alone ( χ2=1.60, P=0.918). The total duration of NAs treatment and the duration of NAs treatment before the application of Peg-IFN-α-2b had no significant difference in the proportion of patients achieving clinical cure at each monitoring point ( χ2=5.67 and 5.47, respectively, P=0.854 and 0.857, respectively). Conclusions:For young and middle-aged CHB patients, baseline HBsAg<50 IU/mL, HBeAg and HBV DNA negative are the characteristics of clinical cure. These patients have a high probability of clinical cure with 12 weeks to 48 weeks of Peg-IFN-α-2b treatment. HBsAg decline to a low level at 12 weeks of treatment can be used as a reference index for good efficacy at 48 weeks of treatment. Some patients can achieve clinical cure after a short course of treatment with Peg-IFN-α-2b (12 weeks or 24 weeks), and even produce high levels of HBsAb. The course of Peg-IFN-α-2b treatment can be personalized.

Objective:To analyze the characteristics of chronic hepatitis B (CHB) patients clinically cured, and to explore the advantageous population and regimen of pegylated interferon-α-2b (Peg-IFN-α-2b) treatment.Methods:A total of 188 CHB patients who were treated with Peg-IFN-α-2b in the Department of Infectious Diseases of the First Hospital of Shanxi Medical University from February 2018 to January 2024 and enrolled in the "China research (Oasis) project on reducing the incidence of hepatocellular carcinoma in hepatitis B patients" in Shanxi Province from September 2020 to January 2024 with clinically cured by Peg-IFN-α-2b therapy were selected as subjects. The basic information and efficacy indicators of patients were collected and analyzed, and the levels of hepatitis B surface antigen (HBsAg) and hepatitis B surface antibody (HBsAb) at baseline, 12 weeks, 24 weeks, 36 weeks, 48 weeks, 72 weeks and 96 weeks of treatment were counted. Patients were divided into negative conversion group and non-negative conversion group according to the status of HBsAg at week 48, and HBsAg levels were compared between the two groups at 12 weeks of treatment. Patients were grouped according to the treatment plan and treatment duration, and the proportions of patients who achieved clinical cure at each monitoring point were compared between groups of sequential combination therapy of nucleo(s)tide analogues (NAs) with Peg-IFN-α-2b and Peg-IFN-α-2b alone, among groups of patients with combination treatment of NAs<5 years, 5 to <10 years and ≥10 years, and among groups of patients with NAs treatment duration <5 years, 5 to <10 years and ≥10 years before the application of Peg-IFN-α-2b. Statistical analysis was performed using chi-square test or Mann-Whitney U test. Results:The age of 188 patients was (43.7±9.9) years old, including 126 males (67.02%) and 62 females (32.98%). There were 150 patients (79.79%) treated with sequential combination therapy of NAs with Peg-IFN-α-2b, and 38 patients (20.21%) treated with Peg-IFN-α-2b alone. The baseline HBsAg level of 188 patients was 51.99(3.26, 250.00) IU/mL, and there were 169 cases (89.89%) with negative hepatitis B e antigen (HBeAg). There were 93 patients (49.47%) with HBsAg <50 IU/mL and 162 cases (86.17%) with negative hepatitis B virus (HBV) DNA at baseline. After 12 weeks, 24 weeks, 36 weeks, 48 weeks, 72 weeks and 96 weeks of treatment, there were 47 cases (25.00%), 47 cases (25.00%), 41 cases (21.81%), 35 cases (18.61%), 14 cases (7.45%) and four cases (2.13%) of HBsAg loss, respectively, and there were 28 cases (14.89%), 33 cases (17.55%), 35 cases (18.62%), 24 cases (12.77%), nine cases (4.79%) and four cases (2.13%) of HBsAg seroconversion, respectively. The levels of HBsAb were 0.63(0.20, 2.08) IU/mL, 3.69(0.68, 19.00) IU/mL, 8.47(1.43, 54.98) IU/mL, 10.96(2.93, 63.42) IU/mL, 15.55(1.10, 82.17) IU/mL and 23.45(2.30, 129.50) IU/mL, respectively. The HBsAg levels at week 12 in the HBsAg negative group (170 cases) and the non-negative group (18 cases) according to the status of HBsAg at week 48 were 0.67(0.03, 36.09) IU/mL and 18.31(5.99, 162.19) IU/mL, respectively. The difference was statistically significant ( Z=2.71, P=0.007). There was no significant difference in the proportion of patients who achieved clinical cure at each monitoring point between patients treated with NAs sequential combined with Peg-IFN-α-2b and patients treated with Peg-IFN-α-2b alone ( χ2=1.60, P=0.918). The total duration of NAs treatment and the duration of NAs treatment before the application of Peg-IFN-α-2b had no significant difference in the proportion of patients achieving clinical cure at each monitoring point ( χ2=5.67 and 5.47, respectively, P=0.854 and 0.857, respectively). Conclusions:For young and middle-aged CHB patients, baseline HBsAg<50 IU/mL, HBeAg and HBV DNA negative are the characteristics of clinical cure. These patients have a high probability of clinical cure with 12 weeks to 48 weeks of Peg-IFN-α-2b treatment. HBsAg decline to a low level at 12 weeks of treatment can be used as a reference index for good efficacy at 48 weeks of treatment. Some patients can achieve clinical cure after a short course of treatment with Peg-IFN-α-2b (12 weeks or 24 weeks), and even produce high levels of HBsAb. The course of Peg-IFN-α-2b treatment can be personalized.