Predictors of CMV Reactivation and Survival in Adult Allogeneic HSCT Recipients without CMV Prophylaxis

Introduction Cytomegalovirus (CMV) is a frequent infectious complication after allogeneic HSCT, with seropositive recipients demonstrating higher mortality in registry studies. Pre-emptive treatment (PET) strategies have widely been implemented universally, however with new prophylactic agents available, at-risk groups need to be identified to ensure CMV prophylaxis is appropriately targeted. Methods Retrospective single centre cohort study of all allogeneic HSCT from 2013-2018 inclusive. Patients were assessed for clinically significant CMV infection (cs-CMVi), visceral disease and survival at a 1-year landmark analysis based on CMV serostatus and donor type (sibling [Sib]/Matched Unrelated Donor [MUD]). CMV PCR was measured by IU/mL, cs-CMVi defined as >1000iu/mL and were treated with PET ganciclovir/valganciclovir, or foscarnet if neutropenic. All MUDs received either "Rutuu" protocol high dose prednisolone (pre 2015) or Thymoglobulin ATG 4.5mg/kg (2015 onwards). Results Of 173 consecutive adult alloHSCTs, cs-CMVi developed in 54% D-/R+ vs 30% D+/R+or- (P Conclusions In alloHSCT recipients without CMV prophylaxis, CMV serostatus and donor type are significant predictors of CMV reactivation and overall survival, with CMV D-/R+ MUDs the highest risk group for cs-CMVi and mortality, therefore potential candidates for CMV prophylaxis.