Serum Cytokine Profiles of Children with Obsessive-Compulsive Disorder Shows the Evidence of Autoimmunity

BACKGROUND Previous reports have described an association between autoimmunity and primary obsessive compulsive disorder. This study aimed to investigate any differences in the levels of T helper 1, 2, and 17 effector cell cytokines between obsessive compulsive disorder patients and the control group. METHODS The study included 34 children (23 males, 11 females), aged between 7 and 17 years, with a diagnosis of obsessive compulsive disorder prior to receiving treatment. The control group consisted of age- and gender-matched children. Study participants were assessed using the Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime version, Children's Yale Brown Obsession Compulsion Scale, and Children's Depression Inventory. Cytokine serum concentrations were measured using the BD Cytometric Bead Array Human Th1/Th2/Th17 Cytokine Kit. RESULTS Interleukin-17A, tumor necrosis factor-α, and interleukin-2 levels were significantly higher in obsessive compulsive disorder patients, However, there was no correlation between T helper 1 and 17 cytokine profiles in the obsessive compulsive disorder group. The duration and severity of obsessive compulsive disorder symptoms were not significantly associated with interleukin-17A, interferon-gamma-γ, interleukin-10, interleukin-6, interleukin-4, and interleukin-2 levels. Interestingly, a negative correlation was found between tumor necrosis factor-α levels and Clinical Global Impression scores. CONCLUSIONS These findings suggest, in some cases, obsessive compulsive disorder may develop on a background of autoimmunity, and interleukin-2, tumor necrosis factor-α, and interleukin-17A may play a role in these autoimmune processes. Therefore, we believe it is important to investigate for obsessive compulsive disorder symptoms in patients with autoimmune disease and, conversely, autoimmune diseases in obsessive compulsive disorder patients.