Correlations between immune and metabolic serum markers and schizophrenia/bipolar disorder polygenic risk score in first-episode psychosis

Aims: There is a strong interest in identifying the biological mechanisms involved in the genetic risk for psychotic disorders. In this study, we evaluated the correlation between serum concentrations of specific molecular markers and the genetic component for schizophrenia and bipolar disorder. Methods: We analysed the association between the polygenic risk score (PRS) and the serum levels of different inflammatory/metabolic markers in a sample of 81 first-episode psychosis patients (FEP) with a diagnosis of schizophrenia or bipolar disorder and 33 controls. Results: A positive correlation of schizophrenia and bipolar disorder PRS with the inflammatory marker C-C Motif Chemokine Ligand 4 serum concentration (ρ = 0.42, P = 1.56 × 10-04 and ρ = 0.40, P = 1.65 × 10-03, respectively) and a negative correlation with the serum ghrelin content (ρ = − 0.35, P = 4.27 × 10-03 and ρ = − 0.45, P = 6.05 × 10-04, respectively) were observed. Conclusion: These findings provide new insight into the biological underpinnings of the PRS component, thus supporting a role of the genetic liability on the inflammatory and metabolic alterations that characterize psychosis onset.