Evaluation of serum matrix-metalloproteinase 9 and tissue inhibitor metalloproteinase-1 in children and adolescents with obsessive compulsive disorder

Obsessive compulsive disorder (OCD), which is found to be irrational or irrational, causing marked tension or significantly affecting functioning; It is defined by the presence of repetitive, compulsive thoughts, images, and/or compulsions (APA 2013).The etiopathogenesis of OCD is not fully understood, and immune system changes are thought to be the initiator or trigger of the disease. Moreover, some types of childhood-onset OCD, PANDAS (Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections) and PANS (Pediatric Acute-onset Neuropsychiatric Syndrome) are triggered by streptococci or other infections(Sivri 2018).Matrix Metalloproteinases (MMPs) are major modulators in the extracellular matrix and provide cell adhesion molecules, neurotrophins and cytokines. Tissue inhibitor metalloproteinases (TIMP) inhibit the effects of MMP.In case of imbalance between MMP-9 and TIMP-1 as a result of damage, various structural and neurochemical changes may occur. These processes can lead to increased excitation and changes in neuronal circulation (Mizoguchi 2013).MMP-9 is the most studied molecule in the central nervous system among all MMPs and is normally found at very low levels in the brain. Although MMPs also play a role in synaptic plasticity, MMP-9 is the MMP most associated with synaptic plasticity, and it is stated to have a role in learning and memory (Bereun 2019).It also plays a role in neurogenesis, neuroplasticity, immune response and neuroinflammation. Studies have been conducted in many neuropsychiatric diseases such as schizophrenia, depression, bipolar disorder, dementia and Alzheimer's in relation to serum MMP-9 levels in adult patients (Yamamori 2013, Rybakowski 2013).In addition, there is a study that shows that serum MMP-9 levels are high in children and adolescents with Attention Deficit and Hyperactivity Disorder (Kadziela-Olech, Halina, 2015.)To the best of our knowledge, there are no studies measuring MMP-9 or TIMP-1 levels in OCD patients. In our study, we plan to evaluate serum MMP-9 and TIMP-1 levels and MMP-9/TIMP-1 ratios in patients diagnosed with OCD in our outpatient clinic.