Background: Serum levels of C-reactive protein (CRP) were measured in patients with deficit schizophrenia (DS) to confirm the association between CRP level and cognitive performance and to determine whether CRP was a new biological indicator with the potential clinical applications in DS patients.
Methods: Three independent samples [41 DS and 50 non-deficit schizophrenia (NDS) and 30 sex- and age-matched healthy controls (HCs)] were recruited in our study. Serum CRP levels were measured by immunofluorescence. The Positive and Negative Syndrome Scale (PANSS) and alternative forms of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) were also assessed. And the relationships between serum CRP levels and both PANSS and RBANS scores were finally analyzed.
Results: The results of serum CRP level were showed significantly different among the three groups and increased from the HCs to NDS patients to DS patients. There were also significant differences in the cognitive subdomain analyses among the three groups. Serum CRP levels were found positively correlated with total and negative PANSS scores, and showed negatively correlated with overall cognitive test scores in the DS samples.
Conclusion: Serum C-reactive protein levels and their association with cognitive performance were different between deficit schizophrenia and non-deficit schizophrenia samples, and higher serum CRP level was associated with worse cognitive performance in the DS patients. The results indicated that CRP could be a potential biomarker, and DS could be a distinct subset of schizophrenia.
Keywords: schizophrenia, deficit schizophrenia, C-reactive protein, inflammation, cognitive impairment