Eotaxin-1/CCL11 correlates with left superior temporal gyrus in bipolar disorder: A preliminary report suggesting accelerated brain aging

Background: Neuropsychiatric disorders have been linked to immune mechanisms. Altered peripheral levels of eotaxin-1/CCL11; a cytokine implicated in allergic reactions and aging process; have been reported in bipolar disorder (BD). Several brain areas, especially the temporal lobe, seem to display volume loss and accelerated aging in BD. This study aimed at exploring potential associations between eotaxins and brain volumes in patients with BD compared to controls. Methods: Twenty-two euthymic patients with BD and 22 controls were enrolled in this study. Serum levels of eotaxin-1/CCL11, eotaxin-2/CCL24 and eotaxin-3/CCL26 were determined alongside brain volumes. Results: There were no differences in the levels of eotaxins between patients and controls. A negative correlation was found between eotaxin-1/CCL11 levels and left-hemisphere's superior-temporal volume only in BD patients, which persisted with covariate adjusted model. Conclusion: This study corroborates the emerging evidence of association between inflammation and brain volumes in BD. Our preliminary results also support the hypothesis of a possible role of eotaxin-1/CCL11 in accelerated brain aging in BD.