IL-23 and TGF-β1 levels as potential predictive biomarkers in treatment of bipolar I disorder with acute manic episode.

BACKGROUND

Growing evidence suggests that immune dysfunction may be involved in the physiopathology of bipolar disorders, with typical first-line treatment using lithium and quetiapine serving to restore pro-inflammation status. This study aimed to explore the relationship between inflammatory cytokines-especially regulatory factors and the effect of combination treatment-with quetiapine and lithium in manic patients.

METHODS

41 patients of bipolar I disorder with manic episode were enrolled and received combination treatment with quetiapine and lithium. Blood sampling and assessments were performed at baseline and after 8-week treatment. YMRS was used to evaluate the severity of manic symptoms at the same time of detecting plasma levels. A control group comprised of 36 age and gender matched healthy volunteers were enrolled, and their blood samples were assessed at the time of enrollment.

RESULTS

TGF-β1 and IL-23 plasma levels in patients were significantly higher than healthy controls at baseline (P<0.05). When comparing remitted patients with non-remitted patients, initial plasma level TGF-β1 was higher (P=0.029) while IL-23 was lower (P=0.035). The plasma levels of TNF-α, TGF-β1, IL-23 and IL-17 significantly decreased after treatment among the patients who achieved response (P<0.05).

LIMITATIONS

The relatively small sample size in patients and control groups should be considered as a limitation of the study.

CONCLUSIONS

The high initial plasma level of TGF-β1 and low initial plasma level of IL-23 indicated better prognosis during combination treatment with quetiapine and lithium in manic patients. The trend of decreasing plasma levels of TNF-α, TGF-β1, IL-23 and IL-17 indicated therapeutic effect.