Infectious complications in adult acute lymphoblastic leukemia (ALL): experience at one single center

Literature provides no specific data concerning the type and the risk factors for infection in adult patients with acute lymphoblastic leukemia (ALL). We retrospectively analyzed 97 adult ALL patients who underwent conventional chemotherapy during a 14-year period with the aim to assess the incidence and the factors affecting onset and outcome of infections. We found that during induction therapy 50% of patients developed infection, mainly caused by gram-negative bacteria and with a mortality rate of 11%. In multivariate analysis age > 60 years was significantly associated with more infections (P = 0.04) and higher related mortality (P = 0.03). Moreover, in 22% of patients infectious complications occurred during consolidation or maintenance therapy. Mortality rate of these infections, mostly due to opportunistic pathogens, was 16%. Factors affecting mortality was the cumulative dose of methylprednisolone given during induction therapy ( < or = 2600 mg = 31% vs. > 2600 mg = 69%; P = 0.03). Among neutropenic patients, adults with ALL represent a peculiar population since they frequently develop gram negative infections during induction and opportunistic infections during post-remission treatments. Advanced age and high-dose methylprednisolone result the major risk factors for infection related mortality in the former therapeutic phase and in the latter one, respectively.