LAUSR

PIN71 ADENOVIRUS VIREMIA IS AN INDEPENDENT PREDICTOR OF PROLONGED TRANSPLANTATION HOSPITALIZATION IN PEDIATRIC ALLOGENEIC HEMATOPOIETIC CELL TRANSPLANT RECIPIENTS: FINDINGS FROM ADVANCE Pérez-Martı́nez A, Owens S, Patrick K, Chandak A, Meng J, Brundage T, Vainorius E, Casciano R, Nichols G, Mozaffari E, Lindemans CA Hospital Universitario La Paz, Madrid, Spain, Great North Children’s Hospital, Newcastle upon Tyne, UK, Sheffield Children's NHS Foundation Trust, Sheffield, UK, LA-SER Analytica, New York, NY, USA, Analytica Laser, a Certara company, Loerrach, Germany, Chimerix, Durham, NC, USA, LASER Analytica, New York, NY, USA, University Medical Center Utrecht, Utrecht, The Netherlands OBJECTIVES: To identify prognostic factors associated with longer transplant hospitalization in pediatric allogeneic hematopoietic cell transplant (allo-HCT) recipientswith adenovirus (AdV) infection.METHODS: AdVance is a retrospective, Europeanmultinational study into allo-HCT recipients who develop AdV infection. Here we focus on predictors of increased length of hospitalization. Review of medical chart data for the six months following allo-HCT identified patients with AdV infection. Fine-Gray multivariate regression models were utilized to identify prognostic factors associated with longer transplant hospitalization in pediatric patients who developed AdV infection following allo-HCT. Models accounted for death as a competing risk and data were censored at one year after allo-HCT. Transplant hospitalization was defined as the time from allo-HCT procedure until hospital discharge. RESULTS: For the transplant hospitalization, median length of stay was 50 days for patients with AdV viremia during the hospitalization (n1⁄4263) versus 34 days for those without AdV viremia (n1⁄4295). Multivariate regression analysis, controlling for age, race, and center effect as a fixed factor, revealed factors independently associated with risk of longer transplant hospitalization: AdV viremia 10,000 copies/mL (HR1⁄45.26; 95% CI: 3.13-8.33; p<0.0001) or from 1000 to 10,000 copies/mL (HR1⁄42.08; 95%CI: 1.32-3.33; p1⁄40.0017); lymphocyte counts <300 cells/mL (HR1⁄41.67; 95% CI: 1.15-2.38; p1⁄40.0062); and graft versus host disease (GvHD) grade 3 (HR1⁄42.86; 95% CI: 1.89-4.35; p<0.0001) or grade 4 (HR1⁄46.25; 95% CI: 3.33-11.11; p<0.0001).CONCLUSIONS: AdV viremia in pediatric allo-HCT recipients is a strong independent predictor of longer hospital stay following allo-HCT. Higher viral burden is associated with increased risk of prolonged transplant hospitalization, independent of other confirmed risk factors such as low lymphocyte counts or GvHD. Approaches that prevent or mitigate high-level AdV viremia could therefore reduce the healthcare resource burden associated with allo-HCT.