Chemokine (C-C motif) ligand 5 (RANTES) concentrations in the peripheral blood of patients with a depressive disorder

Inflammation plays a role in the pathomechanism of depressive disorder. Cytokines interact with iodothyronine deiodinases (DIOs) that are involved in thyroid hormone (TH) metabolism. DIOs are known as modifiers of the inflammatory response. RANTES is a chemokine that has been detected in a wide range of inflammatory disorders, but is less studied in depression. We aimed to investigate the concentration of RANTES in patients with recurrent depressive disorder (rDD) and examine any potential correlation with other molecules, such as interleukins (ILs) and DIOs.The levels of RANTES and other molecules associated with depressive disorder, including deiodinase type 1 (DIO1), interleukin (IL)1β, and IL-6, were measured by enzymatic immune assay (ELISA) in the serum of 43 patients with depressive disorder and 36 controls.RANTES levels were higher in depressed patients than in controls. The level of RANTES was negatively correlated with the deiodinase type 1 (DIO1) level in women diagnosed with rDD. IL-1β and IL-6 levels were significantly higher in depressed patients than in controls. IL-1β was positively correlated with deiodinase type 3 (DIO3). A negative correlation between DIO1 and the number of depressive episodes in women with rDD was observed.With the observed elevated RANTES levels, increases in ILs concentrations, and a possible link between immune aspects and DIOa in patients with rDD, our study contributes to the current pool of knowledge about the complex aetiology of depression and suggests future studies focus on precision mechanisms that explain the link between TH-related molecules and immune molecules.