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).