Psychoimmune Investigation in Obsessive-Compulsive Disorder: Assays of Plasma Transferrin, IL-2 and IL-6 Receptor, and IL-1β and IL-6 Concentrations

Abstract

This study was carried out to investigate the immune function in obsessive-compulsive disorder (OCD). Plasma levels of interleukin (IL)-1β, IL-6, soluble IL-6 receptor (sIL-6R), sIL-2R, and transferrin receptor (TfR), and baseline plasma cortisol levels were measured in 19 OCD patients and 19 normal controls. No significant differences in any of the above immune variables were found between subjects with OCD and normal controls. There was a significant positive correlation between IL·6 or sIL·6R concentrations and severity of compulsive – but not obsessive – symptoms. In subjects with OCD, there was a significant negative relationship between sIL-2R concentrations and plasma cortisol values. In subjects with OCD and in the study group as a whole, there were significant positive relationships between sIL-2R and TfR concentrations.

Decreased Blood Levels of Tumor Necrosis Factor-Alpha in Patients with Obsessive-Compulsive Disorder

“…In line with the present findings, no significant changes in plasma levels of IL-1ß and IL-6 and a normal in vitro production of IL-1ß by peripheral blood mononuclear cells of obsessive-compulsive patients have been reported [10,11].…”

“…No statistically significant differences in lymphocyte subsets have been reported between normal controls and patients with OCD [9]. Maes et al [10] did not find significant changes in plasma levels of interleukin (IL)-1ß, IL-6, soluble IL-2 receptor and soluble IL-6 receptor in obsessive-compulsive patients, while Weizman et al [11] reported no alteration in IL-1ß, IL-2 and IL-3 production by peripheral blood mononuclear cells of patients with OCD.…”

Plasma cytokine abnormalities in drug-naïve, comorbidity-free obsessive–compulsive disorder

“…Results of the study demonstrate that OCD patients had significantly higher levels of IL 2,4, 6,10 and TNF-α compared to healthy controls. However few studies did not find increased levels of TNF, IL-1 or IL-6 (Maes et al, 1994;Brambilla et al, 1997;Weizman et al, 1996;Monteleone et al, 1998;Carpenter et al, 2002;Denys et al, 2004) possibly due to the confounding effects of comorbid mood disorder and medications as reported in metaanalysis (Gray and Bloch, 2012). Importantly, results of current study are in accord with an earlier study reporting increase in interleukin-6 and TNF-alpha levels in drug free patients with OCD (Konuk et al, 2007) and another recent study reporting absence of correlation between antidepressant medication dose and cytokines, chemokines except sTNFr2 (Fontenelle et al, 2012).…”

“…Despite the strong association between OCD and neuroinflammation, only few studies have examined cytokine abnormalities in OCD. However, findings from these studies are inconsistent; while few studies reported altered levels of cytokines (Brambilla et al, 1997;Denys et al, 2004;Fluitman et al, 2010;Konuk et al, 2007;Monteleone et al, 1998) others reported absence of difference compared to controls (Maes et al, 1994;Weizman et al, 1996;Marazziti et al, 1999;Carpenter et al, 2002).…”

Differentiating primary pathophysiologic from secondary adaptational processes

“…Soluble plasma interleukin 2 receptor was found to be elevated in both major depression [Maes et al, 1995;Seidal et al, 1995] and schizophrenia [Rapaport and Lohr, 1994;Gaughran et al, 1998;Barak et al, 1995;Maes et al, 1995], although there are also a few negative studies [Kim et al, 1996;Rothermundt et al, 1998]. However no alterations in this parameter were reported in anxiety disorders [Spivak et al, 1997;Rapaport and Stein , 1994a,b;Maes et al, 1994a]. Antipsychotic treatment was reported to increase sIL-2R levels [Maes et al, 1994b;Pollmacher et al, 1995Pollmacher et al, , 1996Muller et al, 1997], although not all studies could replicate this result [Kim et al, 1995;Pollmacher et al, 1997].…”