Incidence, risk factors, and outcomes of bloodstream infection during conditioning phase before allogeneic hematopoietic stem cell transplantation

Ling Pan; Jia Li; Qingsong Lin; Xiaomeng Feng; Xueyuan Li; Guixin Zhang; Sisi Zhen; Yuqing Cui; Jieru Wang; Yuping Fan; Tingting Zhang; Yigeng Cao; Wenbin Cao; Aiming Pang; Donglin Yang; Xin Chen; Rongli Zhang; Jialin Wei; Qiaoling Ma; Weihua Zhai; Yi He; Mingzhe Han; Erlie Jiang; Sizhou Feng

doi:10.1016/j.jtct.2025.05.027

Incidence, risk factors, and outcomes of bloodstream infection during conditioning phase before allogeneic hematopoietic stem cell transplantation

Transplant Cell Ther. 2025 Jun 25:S2666-6367(25)01225-4. doi: 10.1016/j.jtct.2025.05.027. Online ahead of print.

Authors

Ling Pan¹, Jia Li¹, Qingsong Lin¹, Xiaomeng Feng¹, Xueyuan Li², Guixin Zhang¹, Sisi Zhen¹, Yuqing Cui¹, Jieru Wang¹, Yuping Fan¹, Tingting Zhang¹, Yigeng Cao¹, Wenbin Cao¹, Aiming Pang¹, Donglin Yang¹, Xin Chen¹, Rongli Zhang¹, Jialin Wei¹, Qiaoling Ma¹, Weihua Zhai¹, Yi He¹, Mingzhe Han¹, Erlie Jiang¹, Sizhou Feng³

Affiliations

¹ State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China; Tianjin Institutes of Health Science, Tianjin, China.
² Haihe Laboratory of Cell Ecosystem, Tianjin Medical University, Tianjin, China.
³ State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin, China; Tianjin Institutes of Health Science, Tianjin, China. Electronic address: doctor_szhfeng@163.com.

PMID: 40578622
DOI: 10.1016/j.jtct.2025.05.027

Abstract

Background: Bloodstream infections (BSI) pose critical risks during allogeneic hematopoietic stem cell transplantation (allo-HSCT), yet data on BSI during conditioning phase remain limited.

Objective: To assess the characteristics, risk factors, and outcomes of BSI during conditioning in allo-HSCT patients with hematological diseases.

Study design: We conducted a single-center retrospective cohort study including 2395 consecutive allo-HSCT recipients between September 2013 and September 2023.

Results: BSI occurred in 113 patients (5.7% cumulative incidence), with median onset on day -2. Monomicrobial gram-negative bacteria (73.5%, 83/113) and gram-positive bacteria (18.6%, 21/113) predominated, with polymicrobial BSI in 8.0% (9/113). Carbapenem-resistant gram-negative organisms (CRO) constituted 15.9% (18/113) of infections. Independent BSI risk factors included antithymocyte globulin (ATG)-mediated conditioning (96.5% of BSI cases), aplastic anemia (AA), hematopoietic cell transplantation-comorbidity index (HCT-CI) ≥ 2, and pre-conditioning neutropenia ≥ 7-day. Patients were stratified by risk based on cumulative incidence: low (0 factor ± ATG, 3.3%), intermediate (ATG + 1 factor, 9.3%), and high (ATG + ≥ 2 factors, 21.4%) (p < 0.001). BSI significantly reduced 28-day survival (94.7% vs. 99.7%, p < 0.001), with 5.3% mortality (6/113). CRO BSI exhibited lower survival than non-CRO cases (76.5% vs. 97.9%, p < 0.001). Prior CRO colonization independently predicted CRO BSI (p = 0.003). Appropriate empirical therapy and ceftazidime/avibactam (CAZ-AVI)-based definitive regimens improved early survival.

Conclusion: BSI surveillance should prioritize patients undergoing ATG-based conditioning, particularly those with AA, HCT-CI ≥ 2, or pre-conditioning neutropenia ≥ 7-day. Given the dominant mortality risk of CRO BSI during conditioning, pre-HSCT CRO screening is imperative, and targeted therapies such as CAZ-AVI are critical.

Keywords: Allogeneic hematopoietic stem cell transplantation; Antithymocyte globulin; Bloodstream infection; Carbapenem-resistant gram-negative organism; Conditioning.