Serum Inflammatory Markers and Their Associations with the Integrity of the Cingulum Bundle in Schizophrenia, from Prodromal Stages to Chronic Psychosis

Abstract

Peripheral cytokines may affect the brain through chronic activation of microglia and, as a result, can potentially lead to decreased integrity of white matter of cingulum bundle (CB). Therefore, the aim of the study was to analyze the relationships between peripheral inflammatory markers and the integrity of the CB in various states: from healthy controls, through prodromal states and first-episode psychosis, to long-term schizophrenia. The integrity of the CB was measured using diffusion tensor imaging. We analyzed six parameters: CRP, IL-6, IL-8, IL-10, TNF-α, and IFN-γ. We found that levels of IL-6 and IFN-γ differed significantly between groups. Initial analysis showed some correlations between the inflammatory markers and CB integrity, in particular a correlation with IL-6 that was present in several groups. However, none of the analyzed parameters were associated with the integrity of the CB after correction for multiple comparisons. Conclusions: Our results supported our hypothesis that there are increased levels of inflammatory markers in psychotic disorders, but did not allow to confirm our hypothesis that there is a link between increased peripheral inflammatory markers and decreased integrity of the CB. However, we found some interesting trend levels that need to be verified in larger studies.