Association between inflammation and brain microstructure in First Episode Psychosis investigated with DTI

Diffusion tensor imaging (DTI) allows the noninvasive characterization of white matter integrity, thanks to a model fitting the diffusion profile of water inside the brain. It has been demonstrated that patients affected by psychosis show alterations in the white matter (WM), when investigated with DTI. At the same time, an involvement of immune system in psychosis has been shown, with pro-inflammatory changes. In this study, we combined the analysis of immunomarkers and white matter integrity, in a DTI-general linear model (GLM) framework, to identify possible interactions. We consider a sample of 100 subjects (DTI and peripheral blood immunomarkers, 29 first episode psychosis (FEP) patients, 26 chronic patients and 45 healthy controls), and applied a TBSS analysis with multiple aims: identifying differences in WM integrity between groups; identifying relationships between WM and immune system markers; identifying interactions between FA, immune system and group. We found, in aligmnent with the existing literature, that chronic patients show altered WM in respect both to controls and to FEP patients. Additionally, in FEP and chronic patients we found correlations between a pro-inflammatory status and WM alterations. Finally, we also demonstrated an interaction between group, WM integrity and immune system in the comparison between HC, FEP and chronic patients.