Journal of International Psychiatry

Objective To investigate the correlation between serum inflammatory cytokine levels and clinical symptoms and efficacy in patients with schizophrenia. Methods Fifty patients with schizophrenia who were hospitalised in Wuhu Hospital of Beijing Anding Hospital，Capital Medical University from December 2021 to May 2023 with their first episode or who had been off their medication for more than 4 weeks were included, and 50 healthy volunteers who had their medical check-ups in our hospital during the same period were selected as the control group, and serum interleukin (IL)-2, IL-4, IL-8, IL-10, and tumour necrosis factor (TNF)-alpha concentrations were detected before and after 6 weeks of treatment with olanzapine, and the severity of their psychotic symptoms was assessed using the Positive and Negative Symptom Scale ( PANSS) to assess the severity of patients' psychotic symptoms. To compare the changes in cytokine levels and PANSS scores before and after treatment in schizophrenia patients, to analyse the correlation between baseline levels of inflammatory cytokines and PNASS scores and the difference (post-treatment - pre-treatment), and to explore the relationship between baseline levels of inflammatory cytokines and the difference in PANSS scores using multivariate linear regression analyses. Results The pre-treatment levels of serum IL-10 and TNF-α in the study group were higher than those in the control group, and serum IL-8 levels were lower than those of the control group, and the difference was statistically significant (P < 0.05). After 6 weeks of olanzapine treatment, patients' serum IL-8 concentration increased and IL-10 and TNF-α concentration decreased, and the difference was statistically significant (P < 0.05). Before treatment IL-2 was negatively correlated with negative symptom scores and total scores, IL-10 was positively correlated with general pathological symptom scores and total scores, and TNF-α was negatively correlated with negative symptom scores, general pathological symptom scores, and total scores (P < 0.05).The baseline level of TNF-α was positively correlated with the difference in negative symptom scores (P < 0.05). Multiple linear regression was used to determine the predictive effect of TNF-α: baseline level of TNF-α versus negative symptom score difference (adjusted R-squared = 0.198, β = 0.445, p＝ 0.001). Conclusion Serum inflammatory cytokine levels in schizophrenia patients correlate with clinical symptoms, olanzapine modulates the levels of aberrant inflammatory cytokines in schizophrenia patients, and TNF-α may be able to predict the efficacy of olanzapine on negative symptoms.

Schizophrenia; Inflammatory cytokines; Olanzapine; PANSS