EARLY INFECTIOUS COMPLICATIONS AFTER ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION: PATHOGEN SPECTRUM, PRETRANSPLANT COLONIZATION CONCORDANCE, AND 100-DAY MORTALITY IN A SINGLE-CENTRE COHORT
- 1Moscow Clinical Science and Research Center 52, Russia
Abstract
Introduction: Early infections remain a major cause of morbidity and mortality after allo-HCT. Integrated evaluation of pathogens, colonization, antimicrobial escalation and early death may reveal clinically relevant patterns. Objectives: The aim of this study was to characterize early infectious complications after allo-HCT, assess concordance between pretransplant colonization and subsequent bacteremia, and identify factors associated with 100-day mortality. Materials and methods: We retrospectively analyzed 78 consecutive allo-HCT procedures performed in 76 patients. Outcomes included febrile neutropenia, bacteremia, sepsis, pneumonia, fungal infection by day +30, antibacterial treatment before engraftment, hematopoietic recovery and mortality. Bacteremia required documentation of a bloodstream microorganism. Infection variables were analyzed as binary outcomes. Bloodstream organisms were normalized to species level and compared with organisms detected in throat, urine or intestinal screening before transplantation. Associations were assessed using Fisher’s exact test and Firth penalized logistic regression. Separate multivariable models evaluated sepsis or pneumonia with age and EBMT score. Results: Febrile neutropenia occurred after 59/78 procedures (75.6%), bacteremia after 52/78 (66.7%), sepsis after 14/78 (17.9%), pneumonia after 14/78 (17.9%), and fungal infection by day +30 after 30/78 (38.5%). Gram-negative organisms occurred in 41/52 bacteremia episodes (78.8%), gram-positive organisms in 23/52 (44.2%), and 15/52 episodes (28.8%) were polymicrobial. The leading pathogens were Klebsiella pneumoniae (20/52, 38.5%), Escherichia coli (12/52, 23.1%), and Pseudomonas aeruginosa (8/52, 15.4%). Pretransplant colonization matched at least one bloodstream organism in 20/52 episodes (38.5%). Concordance was highest for E. coli (11/12, 91.7%), compared with K. pneumoniae (4/20, 20.0%) and P. aeruginosa (2/8, 25.0%). Second- and third-line antibacterial therapy was required in 44/64 (68.8%) and 31/57 (54.4%) evaluable procedures. Bacteremia was associated with second line (83.0% vs 29.4%; p < 0.001) and third-line treatment (66.7% vs 20.0%; p = 0.003). Kaplan–Meier estimated overall survival was 94.6% at day +30 and 83.4% at day +100, corresponding to cumulative mortality estimates of 5.4% and 16.6%, respectively. All 100-day deaths occurred after bacteremia (27.5% vs 0%; p = 0.025). Sepsis was associated with 100-day mortality of 64.3% versus 4.9% (OR 35.1; p < 0.001), while pneumonia was associated with mortality of 70.0% versus 8.9% (OR 23.92; p < 0.001). After adjustment for age and EBMT score, sepsis (adjusted OR 27.34, 95% CI 3.56–210.21; p = 0.0015) and pneumonia (adjusted OR 20.45, 95% CI 2.77–150.76; p = 0.003) remained independently associated with 100-day mortality. Discussion: The early infectious burden was dominated by gram-negative bacteremia and frequent antibacterial escalation. Colonization concordance was pathogen-specific and was particularly high for E. coli. Sepsis and pneumonia identified recipients at markedly increased risk of early death. Conclusion: Early bacteremia was frequent after allo-HCT and predominantly gram-negative. Pretransplant screening provided relevant pathogen-specific information, particularly for E. coli. Sepsis and pneumonia were strong independent determinants of 100-day mortality.
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BibTeX
@article{zhelnova2026early,
title = {{EARLY INFECTIOUS COMPLICATIONS AFTER ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION: PATHOGEN SPECTRUM, PRETRANSPLANT COLONIZATION CONCORDANCE, AND 100-DAY MORTALITY IN A SINGLE-CENTRE COHORT}},
author = {Evgeniia ZHELNOVA and Leonid KHORDZHASOV and Ekaterina KARIMOVA and Maryana LYSENKO},
journal = {Hematology, Transfusion and Cell Therapy},
year = {2026},
month = oct,
doi = {10.1016/j.htct.2026.106860},
url = {https://doi.org/10.1016/j.htct.2026.106860},
note = {CC BY},
}
RIS
TY - JOUR
TI - EARLY INFECTIOUS COMPLICATIONS AFTER ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANTATION: PATHOGEN SPECTRUM, PRETRANSPLANT COLONIZATION CONCORDANCE, AND 100-DAY MORTALITY IN A SINGLE-CENTRE COHORT
AU - Evgeniia ZHELNOVA
AU - Leonid KHORDZHASOV
AU - Ekaterina KARIMOVA
AU - Maryana LYSENKO
PY - 2026
DA - 2026/10/23
JO - Hematology, Transfusion and Cell Therapy
DO - 10.1016/j.htct.2026.106860
UR - https://doi.org/10.1016/j.htct.2026.106860
AB - Introduction: Early infections remain a major cause of morbidity and mortality after allo-HCT. Integrated evaluation of pathogens, colonization, antimicrobial escalation and early death may reveal clinically relevant patterns. Objectives: The aim of this study was to characterize early infectious complications after allo-HCT, assess concordance between pretransplant colonization and subsequent bacteremia, and identify factors associated with 100-day mortality. Materials and methods: We retrospectively analyzed 78 consecutive allo-HCT procedures performed in 76 patients. Outcomes included febrile neutropenia, bacteremia, sepsis, pneumonia, fungal infection by day +30, antibacterial treatment before engraftment, hematopoietic recovery and mortality. Bacteremia required documentation of a bloodstream microorganism. Infection variables were analyzed as binary outcomes. Bloodstream organisms were normalized to species level and compared with organisms detected in throat, urine or intestinal screening before transplantation. Associations were assessed using Fisher’s exact test and Firth penalized logistic regression. Separate multivariable models evaluated sepsis or pneumonia with age and EBMT score. Results: Febrile neutropenia occurred after 59/78 procedures (75.6%), bacteremia after 52/78 (66.7%), sepsis after 14/78 (17.9%), pneumonia after 14/78 (17.9%), and fungal infection by day +30 after 30/78 (38.5%). Gram-negative organisms occurred in 41/52 bacteremia episodes (78.8%), gram-positive organisms in 23/52 (44.2%), and 15/52 episodes (28.8%) were polymicrobial. The leading pathogens were Klebsiella pneumoniae (20/52, 38.5%), Escherichia coli (12/52, 23.1%), and Pseudomonas aeruginosa (8/52, 15.4%). Pretransplant colonization matched at least one bloodstream organism in 20/52 episodes (38.5%). Concordance was highest for E. coli (11/12, 91.7%), compared with K. pneumoniae (4/20, 20.0%) and P. aeruginosa (2/8, 25.0%). Second- and third-line antibacterial therapy was required in 44/64 (68.8%) and 31/57 (54.4%) evaluable procedures. Bacteremia was associated with second line (83.0% vs 29.4%; p < 0.001) and third-line treatment (66.7% vs 20.0%; p = 0.003). Kaplan–Meier estimated overall survival was 94.6% at day +30 and 83.4% at day +100, corresponding to cumulative mortality estimates of 5.4% and 16.6%, respectively. All 100-day deaths occurred after bacteremia (27.5% vs 0%; p = 0.025). Sepsis was associated with 100-day mortality of 64.3% versus 4.9% (OR 35.1; p < 0.001), while pneumonia was associated with mortality of 70.0% versus 8.9% (OR 23.92; p < 0.001). After adjustment for age and EBMT score, sepsis (adjusted OR 27.34, 95% CI 3.56–210.21; p = 0.0015) and pneumonia (adjusted OR 20.45, 95% CI 2.77–150.76; p = 0.003) remained independently associated with 100-day mortality. Discussion: The early infectious burden was dominated by gram-negative bacteremia and frequent antibacterial escalation. Colonization concordance was pathogen-specific and was particularly high for E. coli. Sepsis and pneumonia identified recipients at markedly increased risk of early death. Conclusion: Early bacteremia was frequent after allo-HCT and predominantly gram-negative. Pretransplant screening provided relevant pathogen-specific information, particularly for E. coli. Sepsis and pneumonia were strong independent determinants of 100-day mortality.
SN - 2531-1379
SN - 2531-1387
ER -