Understanding infection risks in pediatric hematopoietic stem cell transplantation

Understanding infection risks in pediatric hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT) is an important treatment for both malignant and non-malignant diseases in pediatric patients. While the procedure offers hope for many, infections remain a leading cause of morbidity and mortality, particularly in allogeneic transplants. Advances in HSCT practices—such as the increasing use of alternative donors, ex vivo T cell depletion, and umbilical cord blood transplants—have increased accessibility, but these innovations have also introduced new challenges for infection control management. As infection patterns evolve, it becomes increasingly important to understand underlying risk factors and develop strategies to effectively mitigate these risks.

Published (doi: 10.1002/pDI3.101) on July 14, 2024 inPediatric discoveryThis study, conducted at Hong Kong Children's Hospital, presents a comprehensive analysis of infection rates and risk factors in pediatric HSCT. The research addresses the epidemiology of bacterial, viral and fungal infections in pediatric patients, highlighting their impact on transplant outcomes.

The study analyzed 100 consecutive pediatric HSCT cases from April 2019 to October 2021. It found that 93.2% of allogeneic transplant recipients experienced post-transplant infections, with viral infections being the most common at 90.5%, followed by bacterial (35.1%) and fungal infections (9.5%). In comparison, only 30.8% of autologous transplant recipients had infections. Viral infections showed different patterns, with HHV-6 and BK virus (BKV) appearing early after transplantation, while cytomegalovirus (CMV) and Epstein-Barr virus (EBV) persisted throughout the 2.5-year observation period. Ex vivo T cell depletion was found to significantly increase the risk of viral infections, with hazard ratios ranging from 3.03 to 7.15. In addition, patients with cancers in second complete remission showed higher rates of bacterial infections, while patients with gastrointestinal graft-versus-host-host disease (GVHD) were more susceptible to fungal infections. The study also highlighted an over 10% infection mortality rate observed exclusively in allogeneic HSCT patients with hematologic malignancies receiving cord blood or haploidentical transplants. These findings reinforce the critical need for targeted strategies for risk-adapted prevention to reduce complications associated with the infection.

Dr. Wing Leung, corresponding author of the study, emphasized the importance of personalized approaches in infection management: "Our results highlight the need for tailored strategies to manage infections in pediatric HSCT. By identifying specific risk factors, we can optimize prophylactic measures and improve patient outcomes."

The findings of this study have far-reaching implications for clinical practice. The results pave the way for the development of risk-stratified infection prophylaxis protocols, particularly for high-risk groups such as pediatric patients with hematologic malignancies undergoing alternative donor transplantation. Adopting these targeted approaches could reduce mortality associated with the infection, leading to improved transplant success rates. Looking forward, future research will likely focus on investigating new antifungal and antiviral therapies and refining existing prophylactic therapies to further improve outcomes for pediatric HSCT patients.

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