Pre-treatment blood inflammatory markers as predictors of systemic infection during induction chemotherapy: results of an exploratory study in patients with acute myeloid leukemia

The purpose of this study is to evaluate the role of C-reactive protein (CRP) and ferritin blood levels in predicting the incidence of systemic infection among adult patients with acute myeloid leukemia (AML) treated with induction chemotherapy. Adult patients with newly diagnosed AML who were initially treated with conventional 3 + 7 induction chemotherapy within 5 days of their diagnosis were included. Patients with previous cytotoxic chemotherapy < 3 years, acute promyelocytic leukemia diagnosis, human immunodeficiency virus infection, or significant systemic infection at the time of diagnosis were excluded. Patients were treated with an institutional policy of substantial identity with negligible differences regarding supportive care. Among 110 patients (median age 54.5 years), 39 infectious events in 38 patients were reported, along with 21 episodes of infectious treatment-related mortality (TRM; 19.1 %). Elevated pre-treatment CRP (p = 0.032) and ferritin (p = 0.002) were related to the incidence of systemic infection. The degree of increase of blood CRP and ferritin level was correlated with the extent of leukocytosis. However, patients with elevated inflammatory markers above normal range had increased risk of infection irrespective of whether they had leukocytosis or not, suggesting that expansion of leukemic blast is another factor affecting the elevation of the markers independent to infection propensity and therefore the magnitude of the elevation does not quantitatively predict the risk of infection. Modest elevation of baseline blood inflammatory markers above the normal range could be an indicator for predicting the incidence of systemic infection in patients with AML.