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 understand the etiological surveillance and drug resistance characteristics of Legionella pneumophila (LP) from the aqueous environment of public places in Shanghai, from 2011 to 2020, and provide evidence for surveillance of the disease. Methods:Environmental water samples were systematically collected from public venues in urban and suburban districts of Shanghai for LP surveillance. All the identified LP isolates underwent a series of testings including serotyping, pulsed field gel electrophoresis (PFGE), sequence-based typing, and antimicrobial susceptibility testing. χ2 test or Cochran-Armitage trend tests were used for statistical analysis and for temporal resistance patterns. Results:Among 6 263 water samples, the LP-positive rate was 20.93% (1 311/6 263). The positivity rate decreased from 24.98% (287/1 149) in 2011-2012 to 20.02% (1 024/5 114) in 2013-2020 ( χ2=13.92, P<0.001), with the highest monthly positivity observed from June to August (23.79%, 745/3 132). A total of 1 365 LP strains were isolated, of which 912 were further characterized, including 10 serotypes, 149 PFGE patterns, and 33 sequence types (ST). The predominant serotype was Lp1 (86.84%, 792/912), and the dominant ST was ST752 (29.50%, 269/912). ST clustering revealed two major clonal groups CG1 and CG2, accounting for 91.12% (831/912) of the isolates. The 190 LPs involved in the drug sensitivity test showed three resistance profiles: azithromycin resistance (31.05%, 59/190), ciprofloxacin resistance (0.53%, 1/190) and azithromycin+ciprofloxacin resistance (0.53%, 1/190). Azithromycin-resistant strains were predominantly ST1 (64.41%, 38/59). The antimicrobial resistance rate showed a significant decline, from 48.65% (18/37) in 2011-2012 to 28.10% (43/153) in 2013-2020 ( χ2=9.38, P=0.002). Conclusions:Compared to from 2011 to 2012, both the positivity rate and antimicrobial resistance prevalence of LP in public aqueous environments of Shanghai exhibited an overall decline from 2013 to 2020. The predominant types of LP were serotype Lp1 and sequence type ST752, with notable high-level resistance to azithromycin. Measures as enhancing the enforcement of water safety regulations and prioritizing surveillance of azithromycin resistance in LP were recommended to mitigate public health risks.

Objective:To understand the etiological surveillance and drug resistance characteristics of Legionella pneumophila (LP) from the aqueous environment of public places in Shanghai, from 2011 to 2020, and provide evidence for surveillance of the disease. Methods:Environmental water samples were systematically collected from public venues in urban and suburban districts of Shanghai for LP surveillance. All the identified LP isolates underwent a series of testings including serotyping, pulsed field gel electrophoresis (PFGE), sequence-based typing, and antimicrobial susceptibility testing. χ2 test or Cochran-Armitage trend tests were used for statistical analysis and for temporal resistance patterns. Results:Among 6 263 water samples, the LP-positive rate was 20.93% (1 311/6 263). The positivity rate decreased from 24.98% (287/1 149) in 2011-2012 to 20.02% (1 024/5 114) in 2013-2020 ( χ2=13.92, P<0.001), with the highest monthly positivity observed from June to August (23.79%, 745/3 132). A total of 1 365 LP strains were isolated, of which 912 were further characterized, including 10 serotypes, 149 PFGE patterns, and 33 sequence types (ST). The predominant serotype was Lp1 (86.84%, 792/912), and the dominant ST was ST752 (29.50%, 269/912). ST clustering revealed two major clonal groups CG1 and CG2, accounting for 91.12% (831/912) of the isolates. The 190 LPs involved in the drug sensitivity test showed three resistance profiles: azithromycin resistance (31.05%, 59/190), ciprofloxacin resistance (0.53%, 1/190) and azithromycin+ciprofloxacin resistance (0.53%, 1/190). Azithromycin-resistant strains were predominantly ST1 (64.41%, 38/59). The antimicrobial resistance rate showed a significant decline, from 48.65% (18/37) in 2011-2012 to 28.10% (43/153) in 2013-2020 ( χ2=9.38, P=0.002). Conclusions:Compared to from 2011 to 2012, both the positivity rate and antimicrobial resistance prevalence of LP in public aqueous environments of Shanghai exhibited an overall decline from 2013 to 2020. The predominant types of LP were serotype Lp1 and sequence type ST752, with notable high-level resistance to azithromycin. Measures as enhancing the enforcement of water safety regulations and prioritizing surveillance of azithromycin resistance in LP were recommended to mitigate public health risks.

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 explore the clinical diagnostic and therapeutic characteristics of peripheral primitive neuroectodermal tumor (PNET). [Methods] A retrospective analysis was conducted on the clinicopathological data of a patient diagnosed with seminal vesicle PNET treated in our hospital.Relevant literature was retrieved in PubMed, Web of Science, and CNKI.The clinical features, pathological results, and treatment methods were reviewed. [Results] Including this case, a total of 6 cases were collected.This case underwent a radical cystectomy with transabdominal approach, bilateral seminal vesicle resection, pelvic tumor resection, and ileal bladder surgery.Postoperative pathology confirmed PNET.During the follow-up of 32 months, no local recurrence or distant metastasis recurred. [Conclusion] Seminal vesicle PNET is a rare tumor with high malignancy, rapid progression, and poor prognosis.The current diagnosis mainly relies on pathological biopsy and immunohistochemistry.Surgery is an effective treatment method.