title: Interleukin-6 production and deregulation of the hypothalamic-pituitary-adrenal axis in patients with major depressive disorders.
abstract: The present study was designed to determine whether an association exists between HPA activity and cytokine production in major depression (MD). In 9 patients with MD and 11 control subjects of both sexes, all drug-free, activity of the HPA axis was evaluated by circadian rhythm of plasma cortisol, 24-h free urinary cortisol, an overnight 1 mg dexamethasone suppression test, and an oCRF stimulation test. Spontaneous and LPS-stimulated production of IL-1beta, IL-6, and TNFalpha by peripheral blood mononuclear cells were also determined. We found a significantly elevated spontaneous production of IL-6 in patients with MD (3541.2 +/- 726.8 vs 380.4 +/- 77.5 pg/mL in controls, p < 0.05), while LPS-stimulated production was significantly lower in patients than in control subjects (19,867.7 +/- 3649.2 vs 33,142.2 +/- 15,47.2 pg/mL, p < 0.05). The adrenocorticotropic hormone response to oCRF, evaluated as the area under the curve (AUCACTH) was significantly lower in patients than in control subjects (p = 0.02). A positive correlation between AUCACTH and LPS-stimulated IL-6 secretion was observed in patients with MD (r = 0.75, p < 0.05) but not in controls. These findings suggest that the activation of the inflammatory response described in depression might be associated with long-term hyperactivity of the HPA axis.
authors.affiliation: Institute of Nutrition and Food Technology (INTA), University of Chile, Santiago, Chile.
authors.forename: Derek
authors.initials: D
authors.lastname: Humphreys
authors.forename: Liana
authors.initials: L
authors.lastname: Schlesinger
authors.forename: Marcelo
authors.initials: M
authors.lastname: Lopez
authors.forename: A Verónica
authors.initials: AV
authors.lastname: Araya
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000276:immunology / Q000378:metabolism* / Q000523:psychology; D005260:Female; D006801:Humans; D007030:Hypothalamo-Hypophyseal System / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D010913:Pituitary-Adrenal System / Q000378:metabolism*
chemical_list: D015850:Interleukin-6