Cognitive impairment is a core feature of schizophrenia, associated with significant social and functional impairment. Schizophrenia has also been associated with inflammation and immune changes. Recently it has been showed that IL-6, a pro-inflammatory cytokine, was associated with cognitive impairment.

The aim of this study was to assess the associations between a pro-inflammatory cytokines (IL-6) and an anti-inflammatory cytokine (IL-4) with social cognition in a sample of stable patients with schizophrenia.

Social cognition was assessed using the Face Emotion Identification Task (FEIT) and the Hinting Task in 29 stable outpatients with schizophrenia. Blood was collected and cytokines (IL-4, IL-6) assays were realized (CBA method).

IL-6 levels showed a significant inverse correlation with FEIT global score (p = 0.019, rho = -0.475) and a trend of significant inverse correlation with the Hinting Task (p = 0.079, rho = -0.332). However, IL-4 levels showed no significant association with the FEIT or the Hinting task (rho = 0.079 and 0,121; respectively).

Elevated IL-6 levels seem to play a role in social cognitive impairment in stable patients with schizophrenia. These results should be interpreted with caution due to the limited number of participants in the study.