A modest increase in 11C-PK11195-PET TSPO binding in depression is not associated with serum C-reactive protein or body mass index


ABSTRACT BACKGROUND Immune mechanisms have been implicated in the pathogenesis of depression, and translocator-protein (TSPO) targeted positron emission tomography (PET) has been used to assess neuroinflammation in major depressive disorder. We aimed to: (i) test the prior hypothesis of significant case-control differences in TSPO binding in anterior cingulate (ACC), prefrontal (PFC) and insular (INS) cortical regions; and (ii) explore the relationship between cerebral TSPO binding and peripheral blood concentration of C-reactive protein (CRP). METHODS 51 depressed cases with Hamilton Depression Rating Scale score > 13 (median 17; IQR 16-22) and 25 healthy matched controls underwent dynamic brain 11 C-PK11195 PET and peripheral blood immune marker characterisation. Depressed cases were divided into high CRP (>3mg/L;N=20) and low CRP (