PLASMA SOLUBLE INTERLEUKIN-2-RECEPTOR IN DEPRESSION - RELATIONSHIPS TO PLASMA NEOPTERIN AND SERUM IL-2 CONCENTRATIONS AND HPA-AXIS ACTIVITY

The present study examined the plasma concentration of the soluble int erleukin-2-receptor (sIL-2R) in depressed subjects in relation to hypo thalamic pituitary adrenal (HPA) axis function and plasma neopterin an d serum n-2 concentrations. Plasma sIL-2R concentration was significan tly higher in depressed patients (n = 47) than in controls (n = 19). T here were no significant correlations between plasma sIL-2R and severi ty of illness. In the depressed subjects, there was a highly significa nt relationship between plasma sIL-2R and neopterin concentrations. De pressed patients with pathologically increased plasma neopterin levels had significantly higher plasma sIL-2R values than those with normal serum neopterin. There were no significant relationships between plasm a sIL-2R and indices of HPA-axis function in depression. There was no significant effect of dexamethasone administration on sIL-2R levels. S ignificantly more depressed subjects had measurable serum n-2 levels t han normal controls. Our data support the notion that a moderate activ ation of cell-mediated immunity may play a role in the pathophysiology of depression.