BACKGROUND<\/strong>: Mast cells <\/a>(MCs) mediate inflammation through neuropeptides<\/a> and cytokines<\/a>, along with histamine<\/a> and reactive oxygen species <\/a>(ROS).<\/p>\n Chronic Fatigue Syndrome\/Myalgic Encephalomyelitis\u00a0(CFS\/ME) is an illness characterized by an unexplained disabling fatigue with multiple physiological impairments as well as dysregulated cytokine profiles.<\/p>\n OBJECTIVE<\/strong>: To determine mast cell phenotypes in isolated human PBMCs<\/a>, in healthy controls and in CFS\/ME patients. Second, determine receptor expression of RAGE and its ligand high mobility group box 1 protein (HMGB1).<\/p>\n METHOD:<\/strong> Moderately severe CFS\/ME patients (n=12, mean age 39.25\u00b1SD3.52 years), severe CFS\/ME patients (n=6, mean age 43.00\u00b1SD4.02 years) and healthy controls (n=13, mean age 42.69\u00b1SD3.87 years) were included in this study. CFS\/ME patients were classified according to the 2011 International Consensus Criteria.<\/p>\n LSRFortessa X-20 Flow cytometry was used for the identification of phenotypic peripheral mast cell population in PBMCs using an exclusion marker Lin2 cocktail (anti-CD3, anti-CD14, anti-CD19, anti-CD20 and anti-CD56) and inclusion markers (CD117, CD34, FC\u03b5RI, chymase, HLA-DR and CD154) following comparative investigation. HMGB1 and soluble RAGE expression in plasma was measured by sandwich ELISA assay.<\/p>\n RESULTS:<\/strong> There was a significant increase in CD117+CD34+FC\u03b5RI-chymase- mast cell populations in moderate and severe CFS\/ME patients compared with healthy controls. There was a significant increase in CD40 ligand and MHC-II receptors on differentiated mast cell populations in the severe CFS\/ME compared with healthy controls and moderate CFS\/ME.<\/p>\n There were no significant differences between groups for HMGB1 and sRAGE.<\/p>\n CONCLUSIONS:<\/strong> This preliminary study investigates mast cell phenotypes from PBMCs in healthy controls. We report significant increase of na\u00efve MCs in moderate and severe CFS\/ME patients compared with healthy controls. Moreover, a significant increase in CD40 ligand and MHC-II receptors on differentiated mast cells in severe CFS\/ME patients.<\/p>\n Peripheral MCs may be present in CFS\/ME pathology however, further investigation to determine their role is required.<\/p>\n Novel characterisation of mast cell phenotypes from peripheral blood mononuclear cells in chronic fatigue syndrome\/myalgic encephalomyelitis patients<\/a>, by\u00a0Nguyen T, Johnston S, Chacko A, Gibson D, Cepon J, Smith P, Staines D, Marshall-Gradisnik S in<\/span> Asian Pac J Allergy Immunol<\/em>. 2016 Jun 30.\u00a0[Epub ahead of print]<\/p>\n","protected":false},"excerpt":{"rendered":" Research abstract: BACKGROUND: Mast cells (MCs) mediate inflammation through neuropeptides and cytokines, along with histamine and reactive oxygen species (ROS). Chronic Fatigue Syndrome\/Myalgic Encephalomyelitis\u00a0(CFS\/ME) is an illness characterized by an unexplained disabling fatigue with multiple physiological impairments as well as … Continue reading