Alteration of blood inflammation and glutamate level in parietal precuneus cortex within patients with recent history of suicide attempt: A study of magnetic resonance spectroscopy

Abstract

Suicidal behavior (SB) has been associated with structural and functional impairments in neuroimaging studies and with an increase of peripheral inflammation. We assumed that the increased level of peripheral inflammation markers could be correlated with some abnormalities of brain metabolites in areas involved in suicidal vulnerability such as the anterior and posterior cingulate gyrus cortex (ACC and PCC), the orbito-frontal cortex (OFC) and parietal precuneus cortex (PPC). This hypothesis has been tested by studying the association between levels of 6 cerebral metabolites [i.e. Glutamate (Glu), glutamine (Gln), N-Acetyl aspartate (TNAA), Myo-inositol (Myo)…], 15 biomarkers of inflammation (i.e. C reactive protein (CRP), interleukin (IL) 2, IL1β, IL6, RANTES…) and 8 clinical variables known to be involved in suicidal vulnerability (i.e. depression, childhood trauma, impulsivity, suicidal ideation…). Sixty-six participants were recruited and divided into three groups: 21 depressed patients with a recent SA ( Fig. 1 ). A blood sample was collected to measure peripheral inflammation. We found a higher level of C reactive protein (CRP) in suicide attempters than in both affective controls and healthy controls. CRP level was negatively correlated with concentrations of Glutamate (R = −0.30 P 40% P