Levofloxacin Prophylaxis in Pediatric and Young Adult Allogeneic Hematopoietic Stem Cell Transplantation Recipients Does not Prevent Infective Complications and Infections-related Deaths

Area of Science:

• Hematology
• Infectious Diseases
• Microbiology

Background:

• The use of quinolones for infection prophylaxis in allogeneic hematopoietic stem cell transplantation (allo-HCT) is debated, with limited evidence, especially in pediatric patients.
• This study addresses the controversy by evaluating levofloxacin prophylaxis in allo-HCT recipients.

Purpose of the Study:

• To compare outcomes between patients receiving and not receiving levofloxacin (LVX) prophylaxis after allo-HCT.
• To assess the impact of LVX prophylaxis on survival, graft-versus-host disease (GvHD), bloodstream infections, and gut microbiota composition.

Main Methods:

• A single-center retrospective study analyzed 144 allo-HCT procedures in 143 patients.
• Outcomes including overall survival, event-free survival, acute GvHD (aGvHD), and bloodstream infections were compared between patients receiving (n=74) or not receiving (n=70) LVX prophylaxis.
• Gut microbiota composition was analyzed using 16S rRNA sequencing in a subgroup of 50 patients.

Main Results:

• No significant differences were observed in key allo-HCT outcomes such as cumulative incidence of aGvHD, grade III-IV aGvHD, gut aGvHD, or bloodstream infections between the two groups.
• Patients receiving LVX prophylaxis exhibited a higher incidence of quinolone-resistant bacterial strains (P = .001).
• In the subgroup analysis, LVX prophylaxis was associated with a lower abundance of Blautia (P = .015), Enterococcus (P = .011), and Actinomyces (P = .07) at neutrophil engraftment.

Conclusions:

• Levofloxacin prophylaxis in the context of allo-HCT does not appear to prevent infectious complications.
• Prophylactic levofloxacin use is associated with an increased prevalence of antibiotic-resistant bacterial strains.
• LVX prophylaxis significantly alters gut microbiota composition, reducing the abundance of certain beneficial bacteria.