Febrile events in acute lymphoblastic leukemia: a prospective observational multicentric SEIFEM study (SEIFEM-2012/B ALL)

The purpose of the present study is to estimate the current incidence of febrile events (FEs) and infectious episodes in acute lymphoblastic leukemia (ALL) and evaluate the outcome. We analyzed data on all FEs in a cohort of patients affected by ALL admitted to 20 Italian hematologic centers during 21 months of observation from April 1, 2012 to December 31, 2013. Data about treatment phase, steroids, neutropenia, type and site of infection, and outcome of infection were collected. The population comprehended 271 ALL adult patients. Median age was 46 years old (range 19-75), M/F 1.1:1. We collected 179 FEs occurring during 395 different phases of treatment in 127 patients (45.3% incidence): remission induction treatment 53.1%, consolidation/maintenance 35.7%, treatment for a first or second relapse 44.3%, and refractory disease 85.7%. The incidence of FUO (fever of unknown origin) was 55/395 (13.9%). In the remaining cases, bacteria caused 92 FEs (23.2%), fungi 17 (4.3%), viruses 5 (1%). Mixed infections occurred in 10 cases mainly fungal+bacterial (9/10 cases). Neutropenia was mostly present at onset of FE (89.9% of FEs). Mortality rate was 11.7% (21/179) while 16 deaths occurred with evidence of infection (8.9%). Age > 60 years, neutropenia, poor performance status, steroids, refractory disease, and mixed infections significantly correlated with infection-related mortality. A statistically significant association with mortality was observed also for pulmonary localization and bacteremia. Our study describes the real-life epidemiological scenario of infections in ALL and identifies a subset of patients who are at higher risk for infection-related mortality.