Objective:To analyze the changes in the phylogenetic and antigenic characteristics of the hemagglutinin (HA) gene of influenza virus A(H3N2) [A(H3N2)] during the 2022-2024 influenza seasons in Beijing.Methods:The data of influenza-like cases and A(H3N2) strains from 17 network laboratories and their corresponding sentinel hospitals were collected during the 2022-2024 influenza seasons. The HA genes were amplified and sequenced after extracting nucleic acids of the chosen virus strains. BioEdit, the nucleotide and amino acid sequence identity were conducted, and the maximum likelihood method in MEGA 5.0 software was used to construct the phylogenetic tree of HA genes. Web Logo displayed the amino acid mutation, and the N-glycosylation sites of HA online were analyzed using the NetNGlyc1.0 Server online. The Datamonkey platform was utilized to analyze the positive selection pressure sites of the HA protein.Results:The 2022-2024 influenza season includes 2022-2023 and 2023-2024. During the influenza seasons of 2022-2024, the positive rates of A(H3N2) nucleic acid were 10.35% (2 127/20 543) and 10.47% (4 386/41 876), respectively. In the 2022-2023 influenza season, there were two peaks in the A(H3N2). The comparison of HA genes between all A(H3N2) strains studied with the 2022-2024 vaccine strain (A/Darwin/9/2021) revealed that all of the strains studied have the two amino acid mutations involving 186 and 225 receptor binding sites. There were 31 amino acid substitutions in the 2022-2023 influenza season, of which 18 variant sites involved antigenic determinants. There were 35 amino acid mutations during the 2023-2024 influenza season, of which 14 were related to antigenic determinants. There were changes in the genetic evolutionary subclades of A(H3N2) strains in two influenza seasons: from 2022 to 2023, three evolutionary subclades were co-prevalent together, with the 3C.2a1b.2a.2a.3a.1 accounting for 76.67% (23/30), the 3C.2a1b.2a.1a accounting for 20.00% (6/30), the 3C.2a1b.2a.2a.1 accounting for 3.33% (1/30); from 2023 to 2024, two subclades were prevalent, with 3C.2a1b.2a.2a.3a.1 accounting for 95.12% (39/41) and 3C.2a1b.2a.2a.1 accounting for 4.88% (2/41). The glycosylation site changes of the HA protein of A(H3N2) have been enhanced from 2023 to 2024. The 145 amino acid position of the HA protein of the A(H3N2) was the positive selection site for stress selection site analysis.Conclusions:The evolutionary subclades of the HA gene of A(H3N2) in Beijing showed changes from 2022 to 2024, and the glycosylation site polymorphism of the HA protein of A(H3N2) significantly increased from 2023 to 2024. Continuous monitoring of HA mutations in the A(H3N2) is crucial, providing a basis for developing influenza prevention and control strategies, as well as new strategic support for screening influenza vaccine components, vaccine design, and discovery of drug targets.

Objective:To evaluate the preservation efficacy of 7 non-inactivating virus preservation solutions.Methods:Equal amounts of H1N1 virus were added to 7 commercially available non-inactivating virus preservation solutions, and the samples were stored at -20 ℃, 4 ℃, 25 ℃ and 37 ℃ for 1 hour, 6 hours, 1 day, 3 days, and 5 days. The viral nucleic acid in each simulated sample under different storage conditions was measured using real-time quantitative PCR. The hemagglutination (HA) titer was determined through viral isolation culture and hemagglutination assay, comparing the differences in viral growth activity across different storage solutions and conditions.Results:Except for solution E, the other solutions effectively protected viral nucleic acid at the 4 storage temperatures. In terms of viral activity, solutions A, B, C, and D effectively maintained viral viability. A and B showing the best performance, E and F showed poorer performance, and G performed the worst.Conclusions:Most non-inactivating virus preservation solutions effectively protect viral nucleic acid, but there are significant differences in their ability to maintain viral viability. To ensure optimal virus preservation, it is recommended that medical institutions evaluate the effectiveness of preservation solutions before use.

Objective:To evaluate the efficacy and safety of low-dose post-transplant cyclophosphamide (PTCY) combined with anti-thymocyte globulin (ATG) in preventing graft-versus-host disease (GVHD) in children with β-thalassemia after hematopoietic stem-cell transplantation (HSCT).Method:A retrospective analysis was conducted on 42 children with transfusion-dependent β-thalassemia who underwent HSCT at Zhongshan Hospital, Xiamen University between March 2019 and June 2023. Based on donor source, recipients were grouped into the haploidentical donor group (Haplo-RD, 10 cases) and the unrelated donor group (UD, 32 cases). The UD group was further subdivided into HLA 8/10 matched (2 cases), HLA 9/10 matched (15 cases), and fully HLA-matched (15 cases). The conditioning regimen included fludarabine, busulfan, cyclophosphamide, and thiotepa. GVHD prophylaxis consisted of ATG (4.5 mg/kg), cyclophosphamide (25 mg/kg for 2 days), cyclosporine A (CsA), and mycophenolate mofetil (MMF). Engraftment, GVHD incidence, survival, mortality, and virus reactivation rates were evaluated.Result:The median age was 6 years (range, 2~12). All patients achieved hematopoietic reconstitution. The median times to neutrophil and platelet engraftment were 11 days (range, 10~15) days and 12 days (range, 6~31), respectively. All recipients had >95% peripheral blood STR chimerism by day 30. Grade Ⅲ~Ⅳ acute GVHD occurred in 3 recipients (7.14%), and chronic GVHD occurred in 5 recipients (11.90%) -1 case extensive, 4 cases limited. Both overall survival (OS) and disease-free survival (DFS) were 92.86%. All children in the Haplo-RD group achieved DFS. Eight patients developed cytomegalovirus (CMV) viremia (no CMV disease), with a reactivation rate of 19.05%, and 9 recipients had BK virus-related urinary tract infections (6 cases in the UD group and 3 cases in the Haplo-RD group), for a total incidence of 21.43%.Conclusion:The combination of low-dose PTCY and ATG is a safe and effective strategy to prevent GVHD following haploidentical or unrelated donor HSCT in pediatric β-thalassemia. It is associated with reduced infection and viral reactivation post-transplant and contributes to high survival rates.

Objective:To analyze the changes in the phylogenetic and antigenic characteristics of the hemagglutinin (HA) gene of influenza virus A(H3N2) [A(H3N2)] during the 2022-2024 influenza seasons in Beijing.Methods:The data of influenza-like cases and A(H3N2) strains from 17 network laboratories and their corresponding sentinel hospitals were collected during the 2022-2024 influenza seasons. The HA genes were amplified and sequenced after extracting nucleic acids of the chosen virus strains. BioEdit, the nucleotide and amino acid sequence identity were conducted, and the maximum likelihood method in MEGA 5.0 software was used to construct the phylogenetic tree of HA genes. Web Logo displayed the amino acid mutation, and the N-glycosylation sites of HA online were analyzed using the NetNGlyc1.0 Server online. The Datamonkey platform was utilized to analyze the positive selection pressure sites of the HA protein.Results:The 2022-2024 influenza season includes 2022-2023 and 2023-2024. During the influenza seasons of 2022-2024, the positive rates of A(H3N2) nucleic acid were 10.35% (2 127/20 543) and 10.47% (4 386/41 876), respectively. In the 2022-2023 influenza season, there were two peaks in the A(H3N2). The comparison of HA genes between all A(H3N2) strains studied with the 2022-2024 vaccine strain (A/Darwin/9/2021) revealed that all of the strains studied have the two amino acid mutations involving 186 and 225 receptor binding sites. There were 31 amino acid substitutions in the 2022-2023 influenza season, of which 18 variant sites involved antigenic determinants. There were 35 amino acid mutations during the 2023-2024 influenza season, of which 14 were related to antigenic determinants. There were changes in the genetic evolutionary subclades of A(H3N2) strains in two influenza seasons: from 2022 to 2023, three evolutionary subclades were co-prevalent together, with the 3C.2a1b.2a.2a.3a.1 accounting for 76.67% (23/30), the 3C.2a1b.2a.1a accounting for 20.00% (6/30), the 3C.2a1b.2a.2a.1 accounting for 3.33% (1/30); from 2023 to 2024, two subclades were prevalent, with 3C.2a1b.2a.2a.3a.1 accounting for 95.12% (39/41) and 3C.2a1b.2a.2a.1 accounting for 4.88% (2/41). The glycosylation site changes of the HA protein of A(H3N2) have been enhanced from 2023 to 2024. The 145 amino acid position of the HA protein of the A(H3N2) was the positive selection site for stress selection site analysis.Conclusions:The evolutionary subclades of the HA gene of A(H3N2) in Beijing showed changes from 2022 to 2024, and the glycosylation site polymorphism of the HA protein of A(H3N2) significantly increased from 2023 to 2024. Continuous monitoring of HA mutations in the A(H3N2) is crucial, providing a basis for developing influenza prevention and control strategies, as well as new strategic support for screening influenza vaccine components, vaccine design, and discovery of drug targets.

Objective:To evaluate the preservation efficacy of 7 non-inactivating virus preservation solutions.Methods:Equal amounts of H1N1 virus were added to 7 commercially available non-inactivating virus preservation solutions, and the samples were stored at -20 ℃, 4 ℃, 25 ℃ and 37 ℃ for 1 hour, 6 hours, 1 day, 3 days, and 5 days. The viral nucleic acid in each simulated sample under different storage conditions was measured using real-time quantitative PCR. The hemagglutination (HA) titer was determined through viral isolation culture and hemagglutination assay, comparing the differences in viral growth activity across different storage solutions and conditions.Results:Except for solution E, the other solutions effectively protected viral nucleic acid at the 4 storage temperatures. In terms of viral activity, solutions A, B, C, and D effectively maintained viral viability. A and B showing the best performance, E and F showed poorer performance, and G performed the worst.Conclusions:Most non-inactivating virus preservation solutions effectively protect viral nucleic acid, but there are significant differences in their ability to maintain viral viability. To ensure optimal virus preservation, it is recommended that medical institutions evaluate the effectiveness of preservation solutions before use.

Objective:To evaluate the efficacy and safety of low-dose post-transplant cyclophosphamide (PTCY) combined with anti-thymocyte globulin (ATG) in preventing graft-versus-host disease (GVHD) in children with β-thalassemia after hematopoietic stem-cell transplantation (HSCT).Method:A retrospective analysis was conducted on 42 children with transfusion-dependent β-thalassemia who underwent HSCT at Zhongshan Hospital, Xiamen University between March 2019 and June 2023. Based on donor source, recipients were grouped into the haploidentical donor group (Haplo-RD, 10 cases) and the unrelated donor group (UD, 32 cases). The UD group was further subdivided into HLA 8/10 matched (2 cases), HLA 9/10 matched (15 cases), and fully HLA-matched (15 cases). The conditioning regimen included fludarabine, busulfan, cyclophosphamide, and thiotepa. GVHD prophylaxis consisted of ATG (4.5 mg/kg), cyclophosphamide (25 mg/kg for 2 days), cyclosporine A (CsA), and mycophenolate mofetil (MMF). Engraftment, GVHD incidence, survival, mortality, and virus reactivation rates were evaluated.Result:The median age was 6 years (range, 2~12). All patients achieved hematopoietic reconstitution. The median times to neutrophil and platelet engraftment were 11 days (range, 10~15) days and 12 days (range, 6~31), respectively. All recipients had >95% peripheral blood STR chimerism by day 30. Grade Ⅲ~Ⅳ acute GVHD occurred in 3 recipients (7.14%), and chronic GVHD occurred in 5 recipients (11.90%) -1 case extensive, 4 cases limited. Both overall survival (OS) and disease-free survival (DFS) were 92.86%. All children in the Haplo-RD group achieved DFS. Eight patients developed cytomegalovirus (CMV) viremia (no CMV disease), with a reactivation rate of 19.05%, and 9 recipients had BK virus-related urinary tract infections (6 cases in the UD group and 3 cases in the Haplo-RD group), for a total incidence of 21.43%.Conclusion:The combination of low-dose PTCY and ATG is a safe and effective strategy to prevent GVHD following haploidentical or unrelated donor HSCT in pediatric β-thalassemia. It is associated with reduced infection and viral reactivation post-transplant and contributes to high survival rates.

Acute myeloid leukemia (AML) is a group of highly-heterogeneous clonal diseases. Chemotherapy and hematopoietic stem cell transplantation are considered as effective treatment for AML. For high-risk AML patients, allogeneic hematopoietic stem cell transplantation is an effective therapeutic option. However, some AML patients may still face the problem of disease recurrence after hematopoietic stem cell transplantation. A majority of recurrent patients cannot be effectively treated by chemotherapy or secondary transplantation, which is the main cause of death after allogeneic hematopoietic stem cell transplantation. Therefore, it is of significance to strengthen follow-up of AML patients after allogeneic hematopoietic stem cell transplantation and implement appropriate measures to prevent postoperative recurrence. In this article, the monitoring, drug prevention and cell therapy of recurrence after allogeneic hematopoietic stem cell transplantation in high-risk AML patients were reviewed, aiming to provide reference for improving clinical prognosis of high-risk AML patients undergoing allogeneic hematopoietic stem cell transplantation.

Objective:To explore the key genes related to the development, progression and prognosis of acute myeloid leukemia (AML) based on bioinformatics, and to analyze their functions.Methods:The chip expression profile GSE84881 data set of AML patients including 19 AML samples and 4 normal tissue samples was downloaded from the gene expression omnibus (GEO) database. GEO online tool GEO2R was used to screen the differentially expressed genes (DEG). The DAVID online database was used to make gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis of DEG. The STRING online database was used to analyze the protein interaction (PPI) network of DEG, and the key genes were screened by using the Cytoscape software. The weighted gene co-expression network analysis (WGCNA) was used to build co-expressed network and obtain the central genes.LC-Bio online platform was used to construct Venn diagram and the key genes and central genes in PPI were crossed to finally obtain the true key genes. RNA-seq datasets GSE2191 and GSE90062 of human tissues were downloaded from GEO database to verify the screened key genes. Kaplan-Meier method was used to analyze the effects of key genes on the overall survival (OS) of AML based on the data of GEPIA database.Results:A total of 247 DEG were identified in GSE84881 data set, including 112 up-regulated genes and 135 down-regulated genes. According to the results of GO enrichment analysis, 247 DEG were mainly enriched in the regulation of signal transduction and cell proliferation in the biological process (BP); the cell composition (CC) revealed that these genes were mainly involved in the cytoplasm and exosomes; the molecular function (MF) analysis showed that these genes were mainly enriched in protein binding and calcium binding. Further KEGG pathway enrichment analysis showed that these 247 DEG were mainly involved in NOD-like receptor signal pathway and interleukin 17 (IL-17) signal pathway. And then the 12 key genes were obtained from PPI. WGCNA software was used to screen 13 central genes from GSE84881 dataset and finally 1 real key gene EGF was obtained after taking intersection. Kaplan-Meier method showed that OS time of AML patients in EGF high expression group was decreased than that in EGF low expression group, and the difference was statistically significant( P = 0.044). Conclusions:EGF may be an important diagnosis and treatment target of AML and may become a potential biomarker for clinical treatment and prognosis prediction of AML.

Objective:To investigate the phylogenetic and antigenic characteristics of hemagglutinin (HA) gene of influenza B/Victoria lineage (BV) viruses in Beijing during the 2021-2022 influenza surveillance season, and to analyze whether the circulating BV viruses match the vaccine strain.Methods:Pharyngeal swab specimens from influenza like-illness (ILI) cases in the 2021-2022 influenza surveillance season were collected from surveillance network labs in Beijing and cultured in MDCK cells and chicken embryo to isolate BV viruses. Nucleic acids of the viruses were extracted, and the HA gene was amplified and sequenced. The nucleotide and amino acid sequence identity of the HA gene was analyzed using MEGA5.0 software. A phylogenetic tree of HA gene was constructed using the maximum likelihood method. The N-glycosylation sites in HA were predicted online. Three-dimensional structure of HA was constructed using SWISS-MODEL homologous modeling. Hemagglutination inhibition (HI) test was performed to analyze the antigenicity of BV viruses.Results:A total of 402 BV viruses were collected and 58 strains with full-length HA gene sequences were chosen for further analysis. Compared with the HA gene of this year′s vaccine strain (B/Washington/02/2019), there were 27 amino acid mutations, 11 of which were located in four different antigenic determinants. The phylogenetic analysis revealed that three subgroups of 1A.3, 1A.3a1, and 1A.3a2 co-circulated in Beijing with 54 strains (54/58, 93.10%) clustered to the Clade 1A.3a2, two strains (2/58, 3.45%) clustered to the Clade 1A.3a1, and two strains (2/58, 3.45%) in the same subgroup (Clade 1A.3) as the vaccine component BV strain in 2021-2022. Compared with the vaccine strain (B/Washington/02/2019), two BV strains had an additional N-glycosylation site at residue 197, while the other 56 strains showed no change in N-glycosylation sites. Antigenic analysis showed that 35 BV strains (35/58, 60.34%) were antigenically similar to the vaccine strain and 23 strains (23/58, 39.66%) were low-response strains.Conclusions:Three subgroups of BV viruses co-circulated in Beijing during the 2021-2022 influenza surveillance season. The predominant subgroup was Clade 1A.3a2 (93.10%), showing a certain genetic distance with the vaccine strain (B/Washington/02/2019). Nearly 40% (39.66%) of the viruses were low-response strains. This study indicated that continuous monitoring of the variations of influenza epidemic strains and timely providing laboratory basis for screening vaccine component strains were the basic technical guarantee for coping with influenza pandemic.