S168. THE ASSOCIATION BETWEEN MMP-9 AND CHOROID PLEXUS VOLUME IN SCHIZOPHRENIA

Background Schizophrenia (SCZ) is a severe and chronic brain disorder that affects about 1% of the world population. It is among the most burdensome illnesses with a serious impact on patients, their families and society. To this day, a lot remains unknown about the neuropathological cause and etiology of SCZ. The prominent two-hit theory postulates that early neurodevelopmental abnormalities interact with a later “second hit” which occurs around symptom onset. Recent research points towards the role of inflammation in pathophysiology of schizophrenia. Matrix metalloproteinase-9 (MMP-9) was recently suggested as a potential key player in both first and second “hit” in the pathology of SCZ. It is considered to not only regulate brain development and synaptic plasticity, but to also mediate neuroinflammation. A point of interest for interaction with neuroinflammatory pathways is the Choroid Plexus (ChP). MMP-9 has been reported to be upregulated in ChP in SCZ. Since ChP regulates CSF production and permeability of the blood-CSF-barrier, MMP-9 upregulation in ChP might lead to its enlargement, as well as enlargement of the lateral ventricles and increased extracellular water volume, all found previously in SCZ. We investigate, for the first time, the relationship between MMP-9 blood plasma concentration and volume of ChP in patients with SCZ compared to healthy controls (HC).