Abstracts from the 28th CINP World Congress of Neuropsychopharmacology, Stockholm, Sweden, 3–7 June 2012

Abstract

Objective: IL-8 (CXCL8) is a chemokine that controls migration of neutrophils. Emerging evidence suggests that IL-8 is also involved in diverse physiological functions in the CNS. However, the role of IL-8 in psychiatric disorders remains to be defined. The aim of this study was to assess if IL-8 is altered in patient with suicidal behavior. Methods: We measured CSF and plasma levels of IL-8, as well as the genotype frequency of a single nucleotide polymorphism (-251A/T, rs4073) in the promoter region of the IL-8 gene, in suicide attempters compared to healthy controls. A total of 250 patients and 579 controls from several cohorts were included in the study. Plasma and CSF levels of IL-8 were quantified using ultra-sensitive electrochemiluminescence-based immunoassay. Psychiatric symptoms were rated with the Comprehensive Psychiatric Rating Scale with subscales for anxiety and depression. Results: We found negative correlation between plasma IL-8 levels and anxiety scores in suicide attempters. In the CSF, low IL-8 was associated with more severe symptoms of anxiety in females and depression in males. Female suicide attempters had a significantly lower prevalence of the IL-8-251A allele. Moreover, the-251A allele was coupled to higher plasma IL-8 and lower anxiety. Conclusion: Taken together these findings implicate IL-8 in the pathobiological mechanisms underlying symptoms of anxiety and depression.