Increased autoimmune activity against 5-HT: A key component of depression that is associated with inflammation and activation of cell-mediated immunity, and with severity and staging of depression

Abstract

Background: Depression is characterized by inflammation and cell-mediated immune (CMI) activation and autoimmune reactions directed against a multitude of self-epitopes. There is evidence that the inflammatory response in depression causes dysfunctions in the metabolism of 5-HT, e.g. lowering the 5-HT precursor tryptophan, and upregulating 5-HT receptor mRNA. This study has been undertaken to examine autoimmune activity directed against 5-HT in relation to CMI activation and inflammation. Methods: 5-HT antibodies were examined in major depressed patients (n = 109) versus normal controls (n = 35) in relation to serum neopterin and lysozyme, and plasma pro-inflammatory cytokines (PIC), i.e. in..