Assessing Refractoriness and Infectious Survival Events in AML

Despite therapeutic advance in acute myeloid leukemia (AML), the prognosis remains poor, with an overall survival (OS) of 30% at 5 years \[1, 2\]. Treatment of 1st-line AML in patients under 75 years of age is based on intensive chemotherapy (IC) followed by allogeneic transplantation (hematopoietic stem cell transplantation, HSCT) \[3\]. Following its administration, a phase known as aplasia ensues, during which patients are severely immunocompromised. This period of aplasia therefore carries a very high risk of infectious events, despite management in protected areas and infectious prophylaxis. Infectious problems remain one of the leading causes of mortality in the initial phase of AML treatment \[4\]. The incidence of sepsis, the microorganisms involved and the complications arising from infectious episodes during chemotherapy remain poorly described, as do their long-term prognostic consequences for these patients \[5,6\]. Moreover, there is a "dogma" among hematologists dealing specifically with AML that intensive chemotherapy during which there are no infectious events is often a sign of non-response. Although this "popular" belief has never been verified prospectively or even retrospectively, it is based on the observation of many generations of clinicians. This belief suggests that immune stimulation during aplasie could promote remission by inducing an anti-leukemic immune response. Furthermore, numerous cases of "spontaneous" remission (i.e. in AML patients receiving no active treatment) following infections or highly immune-stimulating events have been reported in the literature \[7-10\]. It might therefore be hypothesized that infectious events occurring during the post-intensive chemotherapy aplasia phase for AML could favor the achievement of remission by nonspecific immune stimulation. The aim of this study is to describe the incidence and type of septic episodes occurring in patients undergoing intensive treatment for acute myeloid leukemia, and to assess the impact of these episodes on patient prognosis, notably via the risk of relapse and long-term survival.