자살을 기도한 우울증 환자에서 사이토카인의 병태생리적 역할

The Pathophysiological Role of Cytokines in Suicide Attempters with Major Depressive Disorder

Objectives：Cytokines are known to play an important role in the pathogenesis and the pathophysiology of major depressive disorders. However, the role of cytokines in suicide in major depression has not been explored thoroughly. The purpose of this study is to identify the roles of cytokine interaction of Th1, Th2, Th3 cytokines in suicidal depressive patients. Methods：110 major depressive patients (29 depressive patients without suicidal ideation, 32 depressive patients with suicidal ideation, and 49 depressive patients with suicide attempts) diagnosed by DSM-IV criteria were included in this study. The severity of suicide ideations and attempts was measured by Lethality of Suicide Attempt Rating Scale (LSARS) and Risk-Rescue Rating (RRR) system. Cytokine productions (TNF-α, IFN-γ, IL-2, IL-4, and IL-6) upon mitogen stimulation were measured by ELISA in a whole blood assay. TGF-β1 were measured in plasma by ELISA. Results：There were no significant differences in age, sex and BMI among the three groups. IL-2 and IL-6 levels were significantly lower in the suicide attempt group than other two groups while TNF-α, IFN-γ, IL-4 and TGF-β1 did not differ among the groups. Significant positive correlations between TNF-α/IL-4, IL-6/IL-4, IFN-γ/IL-4 and IL-6/TGF-β1 ratio and LSARS scores in suicidal patients were found. In addition, there were significant correlations between TNF-α/IL-4 or IL- 6/IL-4 and RRR scores in suicidal patients. Conclusion：These results indicate that decrease in Th1 cytokines may be associated with suicidal behavior in major depression. These findings suggest that cytokines may play a role in the pathogenesis of suicidal depression.