The impact of pre-transplant respiratory virus detection on post-transplant outcomes in children undergoing hematopoietic cell transplantation.

BACKGROUND: Pre-transplant respiratory virus (RV) infections have been associated with negative transplant outcomes in adult hematopoietic cell transplantation (HCT) recipients. In the era of HCT delay due to high-risk RVs, we examined the impact of pre-transplant RV detection on transplant outcomes in a pediatric HCT recipients.

METHODS: This retrospective cohort study included myeloablative allogeneic HCT recipients from 2010 to 2019. All patients were screened for RV at least once within 90 days before HCT using RT-PCR, regardless of symptoms. Post-transplant outcomes included days alive and out of hospital (DAOH) and progression to lower respiratory tract infection (LRTI).

RESULTS: Among 310 patients, 134 had a RV detected in the 90 days prior to HCT. In univariable analysis, transplant factors including younger age, total body irradiation, umbilical cord blood transplantation, lymphocyte count less than 100/mm3, and HCT comorbidity index score ≥3, and viral factors including symptomatic infection, human rhinovirus (HRV) as a virus type, and symptomatic pre-transplant upper respiratory tract infection (URTI) were associated with fewer DAOH. In multivariable analysis, transplant factors remained significant, but not viral factors. There was a higher incidence of progression to post-transplant LRTI with the same pre-transplant RV if the last positive PCR before HCT was ≤30 days compared to >30 days (p=0.007).

CONCLUSION: In the setting of recommending HCT delay for high-risk RVs, symptomatic URTI, including HRV infections, may lead to increased duration of hospitalization and early progression to LRTI when transplantation is performed within 30 days of the last positive PCR test.