title: Heterogeneous medically unexplained symptoms and immune function.
abstract: It has been suggested that dysregulation of immune-to-brain communication plays a role in the biopsychological process underlying medically unexplained symptoms (MUS). Immune and non-immune stressors can both be involved in the activation of the central sickness-behavioural-system leading to complaints like malaise, pain and fatigue. We hypothesized increased pro-inflammatory and/or reduced anti-inflammatory cytokine activity to exist in MUS patients. Twenty-seven participants (4 male; 23 female) with heterogeneous MUS were compared with 27 healthy controls (6 male; 21 females). Blood samples were analysed for leukocyte subset cell counts, in vitro T-cell mitogen-stimulated cytokine production (IL-2, IL-4, IL-5, IL-6, IL-10, TNF-alpha and IFN-gamma) and in vitro monocyte cytokine release (IL-1beta, IL-6, IL-8, IL-10 and TNF-alpha) in response to increasing concentrations of LPS. No significant group differences were found for any of the cytokines measured. One unexpected exception was an elevation in the number of circulating B and NK-cells in participants high on MUS. Nonetheless, no support was found for the hypothesized immunological dysregulation in peripheral blood leukocyte function of MUS patients.
authors.affiliation: Department of Clinical and Health Psychology, Utrecht University, Faculty of Social and Behavioural Sciences, P.O. Box 80.140, 3508 TC Utrecht, The Netherlands. j.h.houtveen@fss.uu.nl
authors.forename: Jan H
authors.initials: JH
authors.lastname: Houtveen
authors.forename: Annemieke
authors.initials: A
authors.lastname: Kavelaars
authors.forename: Cobi J
authors.initials: CJ
authors.lastname: Heijnen
authors.forename: Lorenz J P
authors.initials: LJ
authors.lastname: van Doornen
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001402:B-Lymphocytes / Q000276:immunology; D016022:Case-Control Studies; D016207:Cytokines / Q000097:blood*; D005260:Female; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology; D016131:Lymphocyte Subsets / Q000166:cytology / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D015213:Neuroimmunomodulation / Q000276:immunology*; D012016:Reference Values; D012803:Sick Role; D013001:Somatoform Disorders / Q000097:blood / Q000276:immunology*; D018709:Statistics, Nonparametric; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D016207:Cytokines