Aim: Several lines of evidence suggest that major depressive disorder is associated with an inflammatory status. Tumor necrosis factor-alpha has been investigated as a potential molecular target in mood disorders. Tumor necrosis factor-alpha exerts its activity through binding to specific cell membrane receptors named as TNFR1 and TNFR2. The aim of the present study was to investigate soluble plasma TNFR1 (sTNFR1) and TNFR2 levels (sTNFR2) in major depressive disorder patients.
Methods: Female outpatients with major depressive disorder (n = 30) were compared with a healthy control group (n = 19). Severity of depressive symptoms was evaluated on Beck Depression Inventory; post-traumatic stress disorder (PTSD) symptoms were evaluated on PTSD Checklist-Civilian Version; and childhood abuse and neglect on the Childhood Trauma Questionnaire. Plasma tumor necrosis factor-alpha and its soluble receptors were measured by ELISA.
Results: Patients had no changes in tumor necrosis factor-alpha concentrations but did have increased sTNFR1 (P < 0.001) and sTNFR2 (P < 0.001) levels compared to controls. Plasma level of sTNFR1 was positively predicted by age (B = 0.25, P = 0.05) and PTSD-like symptoms (B = 0.41, P = 0.002) and plasma levels of sTNFR2 by depression severity (B = 0.67, P < 0.001).
Conclusions: Soluble tumor necrosis factor-alpha receptors could be reliable markers of inflammatory activity in major depression.