1591. the Impact of Pretransplant Respiratory Virus Infection in Pediatric Hematopoietic Cell Transplant Recipients

Abstract Background Respiratory virus infections (RVIs) in adult hematopoietic cell transplant (HCT) candidates have been shown to impact posttransplant outcomes; however, there are few studies in pediatric patients. We sought to evaluate the role of specific viruses and the location of viral infection on post HCT outcomes. Methods We evaluated allogeneic pediatric HCT recipients receiving myeloablative conditioning from 3/2010–3/2018. All patients had a multiplex PCR for RVIs prior to HCT, regardless of symptoms. Delaying HCT was recommended when feasible for RSV, parainfluenza, metapneumovirus, adenovirus, and influenza, but not routinely for human rhinovirus (HRV) and endemic coronaviruses. We utilized Cox proportional hazards models to evaluate progression to lower respiratory disease (LRD) post HCT and linear regression models to evaluated days alive and out of hospital (DAOH) by 100 days post HCT. Results Of 310 allogeneic HCT recipients receiving myeloablative conditioning, 133 (43%) were positive for a RVI before HCT. Baseline characteristics were notable for differences for age, recipient CMV serostatus, and delayed HCT (Table 1). The most common RVI was HRV (97, 73%) and 81 (61%) patients were symptomatic at the time of detection. Most patients had a URI (92%) and 11 patients had LRD (3 proven, 8 possible). In univariate analysis, HRV as virus type was associated with fewer DAOH and preHCT URI as location of viral infection (with and without symptoms) trended towards fewer DAOH (Figure 1a). When adjusted for age, preHCT lymphocyte count, cell source, and conditioning regimen, both HRV and preHCT URI showed a trend towards fewer DAOH, but no significant association was found (Figure 1b,c). Twenty patients progressed to LRD after HCT with the same preHCT RVI; no factors, including delay of transplant, were associated with reduced progression to LRD. (A) Univariable linear regression for DAOH, (B) Multivariable linear regression for DAOH by viral type, (C) Multivariable linear regression for DAOH by viral location and symptom composite. Conclusion In this single center study, HRV as virus type and URI as location of viral infection before myeloablative allogeneic HCT were associated with increased hospitalization after HCT, but not in multivariate models. Larger multicenter studies are needed to provide timely evaluation and adequate statistical power to definitively determine role of URI versus LRD and the impact of transplant delay and treatment strategies. Disclosures Yae-Jean Kim, MD, PhD, Janssen: Grant/Research Support|Korean Society of Pediatric Infectious Diseases: Grant/Research Support|Ministry of Trade, Industry and Energy: Grant/Research Support|MSD: Grant/Research Support chikara Ogimi, MD, Horiba: payment for a lecture Michael J. Boeckh, MD PhD, Allovir: Advisor/Consultant|Amazon: Grant/Research Support|Ansun Biopharma: Grant/Research Support|EvrysBio: Advisor/Consultant|Gates Ventures: Grant/Research Support|Gilead Sciences: Advisor/Consultant|Gilead Sciences: Grant/Research Support|GlaxoSmithKline: Advisor/Consultant|GlaxoSmithKline: Grant/Research Support|Helocyte: Advisor/Consultant|Janssen: Advisor/Consultant|Janssen: Grant/Research Support|Kyorin Pharmaceuticals: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Moderna: Advisor/Consultant|Moderna: Grant/Research Support|Regeneron: Grant/Research Support|ReViral: Advisor/Consultant|Symbio: Advisor/Consultant|Takeda: Grant/Research Support|Vir Biotechnology: Advisor/Consultant|Vir Biotechnology: Grant/Research Support Janet A. Englund, MD, Astra Zeneca: Advisor/Consultant|Astra Zeneca: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Meissa Vaccine: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support|SanofiPasteur: Advisor/Consultant Alpana Waghmare, MD, Allovir: Grant/Research Support|Ansun Biopharma: Grant/Research Support|Devarra Therapeutics: DSMB|Kyorin Pharmaceutical: Advisor/Consultant|Pfizer: Grant/Research Support|Vir/GSK: Grant/Research Support.