Novel inflammatory targets for immunotherapies in pediatric patients with trichotillomania

Immune dysregulation may be important in the etiology of obsessive-compulsive and related disordersandbody-focusedrepetitivebehaviors, such as Trichotillomania (TTM). The role of inflammation and inflammatory markers in TTM has received relatively little attention. This study was aimed to determine the expression levels of inflammatory markers (i.e. IL-1β, IL-1α, IL-4, IL-6, IL-17, TNF-α and TGF-β) in peripheral blood mononuclear cells of children with TTM and healthy controls and to evaluate their association with clinical variables. Seventy-seven patients with TTM and 107 healthy controls were enrolled in the study. Peripheral blood was collected in standardized conditions. The mean age of patients and controls did not differ significantly (10.8 ± 4.4 and 12.0 ± 3.2 years; respectively). The majority of patients with TTM and controls were females (n = 55, 71.4 % and n = 55, 51.4 %; respectively); with a greater preponderance of females among TTM. Patients with TTM had significantly elevated expression levels of TNF-α, IL-6 and IL-17 compared to controls. However, the expression level of IL-4 was significantly reduced in TTM patients compared to controls. Accordingly, we found a pro-inflammatory state in TTM and those findings may suggest novel treatment options for TTM and further, cross-disciplinary studies focusing on neuro- inflammation in TTM conducted on larger samples are needed.