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An imbalance in the production of IL-1β and IL-6 by monocytes of bipolar patients: restoration by lithium treatment


  • The authors of this paper do not have any commercial associations that might pose a conflict of interest in connection with this manuscript.

Esther M. Knijff, Lab Ee 987b, Department of Immunology, Erasmus MC, PO Box 1738, 3000 DR Rotterdam, The Netherlands.
Fax: +31 10 408 9456;


Objectives:  To study the ex vivo interleukin (IL)-1β and IL-6 production of monocytes in bipolar disorder (BD) patients in the absence/presence of lithium.

Methods:  Monocytes of outpatients with DSM-IV BD (n = 80, of whom 64 were lithium-treated) and of healthy control subjects (n = 59) were cultured in vitro and exposed (24 h) or not exposed to lipopolysaccharide (LPS) and/or graded concentrations of lithium chloride (LiCl). IL-1β and IL-6 production was assessed by enzyme-linked immunosorbent assay (ELISA) (supernatants).

Results:  Monocytes stimulated by LPS from non-lithium-treated bipolar patients were characterized by an abnormal IL-1β/IL-6 production ratio, i.e., low IL-1β and high IL-6 production. Lithium treatment increased IL-1β and decreased IL-6 production and thus restored the aberrant ratio. In vitro exposure of monocytes to LiCl did not have the same effects as lithium treatment: the procedure decreased IL-1β production and had minimal effects on IL-6 production.

Conclusions:  Blood monocytes have an altered proinflammatory status in BD. Lithium treatment restores this altered status. Short-term in vitro exposure of monocytes to lithium has other effects than lithium treatment.