06 Set Incidence, risk factors and outcome of pre-engraftment blood-stream infections (PE-BSI) in 271 allogenic hematopoietic stem cell transplantation (HSCT)

Blood stream infections (BSI) complicate the neutropenic phase of HSCT. Knowledge of aetiology and antibiotic resistance is crucial to set up an effective antibiotic therapy and reduce mortality.

Pre-engraftment (PE) BSI were studied retrospectively in 271 patients undergoing allogenic HSCT between 2013 and 2016. We investigated incidence, risk factors (RF) and microbiological data. We looked for RF for overall survival (OS) at 60-day after HSCT and studied PE-BSI impact on infection-related mortality (IRM).

Incidence of PE-BSI was 30%. Cox-regression multivariate found only an active haematological disease status (HDS) at HSCT as an independent RF for PE-BSI [HR 1.8 (1.1-3.2)]. Single-species Gram-negative bacteria (GNB) and Gram-positive bacteria (GPB), respectively sustained 32% and 50% of PE-BSI. Attributable mortality was 5% and pathogen-related (0% for GPB, 15% for GNB).

OS at 60-day was 88%. Binary logistic regression showed the negative impact on OS of active HDS (OR 2.47) and PE-BSI (OR 3.2); donor type did not affect significantly the outcome.

Landmark analysis evaluated the impact of PE-BSI on IRM at 60-day: IRM was 6.7%, 11.4% and 15.3% in HSCT recipients without PE-BSI, in those with GPB-BSI and in the others with GNB-BSI, respectively (p 0.29).

Despite attributable mortality is low, PE-BSI is associated with a poorer OS at 60-day and a higher IRM; this is probably a marker of major comorbidities or systemic complications, which justify the poorer clinical course.