Soluble Intracellular Adhesion Molecule-1 in Patients with Unipolar or Bipolar Affective Disorders: Results from a Pilot Trial

BACKGROUND: Immunological and vascular markers may play a role in the pathophysiology of mood disorders and mood changes. AIM: To test whether the cell adhesion molecule soluble intracellular adhesion molecule-1 (sICAM-1) may serve as a biomarker for patients with unipolar or bipolar affective disorders when compared to a healthy control group, and whether sICAM-1 blood levels change during different mood states. METHODS: sICAM-1 serum concentrations were compared between 20 healthy controls and 48 patients with affective disorders (unipolar, bipolar II and bipolar I disorder) during different mood states (euthymic mood state, depression or mania). RESULTS: When compared to healthy controls, patients with affective disorders had significantly higher sICAM-1 levels during the euthymic state (p = 0.015). Differences became more pronounced during depression (p = 0.013). When unipolar and bipolar patients were analyzed separately, unipolar patients significantly differed from controls during the euthymic and depressive mood state, while bipolar II patients showed a trend towards higher sICAM-1 levels during depression. Patients with bipolar I disorders had significantly higher sICAM-1 levels during manic states when compared to controls (p = 0.007). CONCLUSIONS: sICAM-1 elevation in unipolar and bipolar patients, independent of mood changes, might support the hypothesis of chronic immune activation and endothelial dysfunction in patients with affective disorders.