Correlations of serum epidermal growth factor and C-reactive protein with cognitive function in patients with schizophrenia

Objective To investigate the relationships of serum epidermal growth factor (EGF), C-reactive protein (CRP) and their interactions with cognitive function in patients with schizophrenia.

Methods According to the diagnostic criteria of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-Ⅳ) for schizophrenia, 117 patients were recruited in this study.Patients'mental symptoms and cognitive function were assessed using the Positive and Negative Symptom Scale (PANSS) and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).Enzyme-linked immunosorbent assay (ELISA) and immunoturbidimetric method were used to detect the serum concentrations of EGF and CRP, respectively.The correlations of EGF and CRP with cognitive function were explored using correlation and hierarchical regression analysis.

Results Correlation analysis showed that EGF was significantly negatively correlated with CRP (r=-0.550, P < 0.001).hierarchical regression results showed that the interaction terms of EGF and CRP (β=0.411, t=4.436, P < 0.001) could predict visual span, and increase of 0.146 in the new model (R²=0.209) compared with the original model, showing the interaction item could explain 14.6% of the change of visual span.

Conclusion The interactions between CRP and EGF may be related to the cognitive function in patients with schizophrenia, which is helpful to explore objective markers of cognitive deficits in schizophrenia.