Cognitive Impairment, Fatigue, and Cytokine Levels in Patients with Acute Myelogenous Leukemia or Myelodysplastic Syndrome

Background: The objective of the current study was to assess the correlations between cognitive function, fatigue, quality of life, and circulating cytokine levels in patients with acute myelogenous leukemia (AML) and myelodysplastic syndrome (MDS).

Methods: Fifty-four patients with AML/MDS were seen for pretreatment evaluation of their cognitive function and symptoms. Fifty percent of the sample was reevaluated 1 month later, when response to protocol chemotherapy was assessed.

Results: A significant proportion of patients had impaired cognitive function prior to the institution of chemotherapy. Sixty-five percent of patients also experienced significant fatigue. Levels of the circulating cytokines interleukin 1 (IL-1), IL-1 receptor antagonist (IL-1RA), IL-6, IL-8, and tumor necrosis factor-alpha (TNF-alpha) were elevated highly compared with normal controls. Higher IL-6 levels were associated with poorer executive function, whereas higher IL-8 levels were associated with better memory performance. IL-6, IL-1RA, and TNF-alpha levels were related to ratings of fatigue. Fatigue and cognitive dysfunction were unrelated. Hemoglobin levels were not associated significantly with either cognitive dysfunction or fatigue. Patients who obtained a complete response tended to have better fine motor control at baseline and lower circulating IL-1 levels. Treatment did not have a significant impact on cognition, although fatigue levels tended to increase.

Conclusions: Patients with AML/MDS are highly symptomatic and experience cognitive impairment and fatigue before the initiation of their treatment. The current results indicated a correlation between these symptoms and levels of circulating cytokines, providing some support to the hypothesis that cancer-related symptoms are related at least in part to cytokine-immunologic activation. Elucidation of immunologic correlates of symptoms will allow for targeted interventions.