Increased levels of alpha-1-acid glycoprotein and interleukin-6 in refractory depression

Plasma concentrations of alpha-1-acid glycoprotein (AGP), C-reactive protein (CRP), interleukin-6 (IL-6), and soluble interleukin-6 receptor (sIL-6R) as well as the changes in glycosylation of AGP were measured in 60 patients with major depression hospitalized at the Department of Psychiatry, Medical Academy in Bydgoszcz, and in 20 age- and sex-matched controls. Thirty-four depressed patients met the criteria of refractory depression. Patients with refractory depression (RD) had a longer duration of the illness and the last depressive episode than the responders to antidepressant treatment. RD patients had higher concentrations of AGP, CRP, IL-6, and higher monocyte count as well as the different glycosylation patterns of AGP (higher values of reactivity coefficient, AGP-RC) compared with non RD patients. Depressed patients who exhibited DST non-suppression had significantly higher values of AGP than patients showing suppression on this test. These results may suggest an elevation of acute phase response in refractory depression. Depression 3:170–175 (1995). © 1995 Wiley-Liss, Inc.