We previously reported elevated serum levels of the cytokines interleukin-6 (IL-6) and transforming growth factor-β (TGF-β) in patients with anorexia nervosa (AN). We investigated the cellular production of these two cytokines and of interferon-γ (IFN-γ), interleukin-1α (IL-1α), and tumor necrosis factor-α (TNF-α) in subjects with AN, bulimia nervosa (BN), and obesity as well as in normal-weight control subjects.
Supernatant fluids from isolated peripheral blood mononuclear cells (PBMC) incubated with and without concanavalin A (ConA) were assayed for cytokine concentrations by enzyme-linked immunosorbent assay (ELISA).
Significant differences across the four groups were found in the stimulated cellular production of IFN-γ and IL-6. Stimulated IFN-γ production was elevated in the AN group compared to controls. IL-6 production was significantly elevated in obese subjects relative to the two normal-weight groups, BN and controls, and tended to be higher in the AN group than in the controls, but not significantly so. IL-1α production was greater in obese subjects.
The findings of increased IFN-γ production and a tendency toward increased IL-6 production (both of which suppress food intake in animals) in individuals who severely restrict food intake suggest a potential role for these cytokines in the pathogenesis of AN. Elevated IL-6 and IL-1α production by PBMC in obese individuals requires further investigation to determine if these cytokines contribute to the development or perpetuation of obesity. © 2000 by John Wiley & Sons, Inc. Int J Eat Disord 28: 293–302, 2000.