RT Journal Article SR Electronic T1 Preliminary Evidence for [11C]PBR28 Sensitivity to Alcohol Challenge in Human Brain JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 458 OP 458 VO 61 IS supplement 1 A1 Hillmer, Ansel A1 Drake, Lindsey A1 Angarita, Gustavo A1 Matuskey, David A1 Kapinos, Michael A1 Ye, Yunpeng A1 Nabulsi, Nabeel A1 Huang, Yiyun A1 O'Malley, Stephanie A1 Carson, Richard A1 Cosgrove, Kelly YR 2020 UL http://jnm.snmjournals.org/content/61/supplement_1/458.abstract AB 458Objectives: Alcohol elicits complex effects on the brain’s immune system, however, limited in vivo tools exist to study these phenomena in people. Positron emission tomography (PET) imaging of the 18-kDa translocator protein (TSPO) provides a useful biomarker that is sensitive to dynamic changes in the immune system. For example, the robust immune stimulus endotoxin increases [11C]PBR28 VT by 40-50% in human brain (Sandiego et al., 2015). The goal of this work was to determine whether [11C]PBR28 PET imaging is sensitive to acute immune effects elicited by an oral alcohol challenge. Methods: Study participants were six people (4M, 2F; Age 21-31) who reported recent drinking experience consistent with a binge alcohol event. Baseline dynamic [11C]PBR28 PET scans were acquired in the morning, followed by a standardized lunch. Subjects then consumed an alcohol dose adjusted by age, sex, and weight, designed to achieve blood alcohol concentrations (BAC) of 80 mg/dL over 90 min. Following a 60 min rest period, a second post-alcohol [11C]PBR28 PET scan was acquired. Arterial blood samples were acquired at 30 min intervals to measure BAC. Dynamic PET data were acquired with a Siemens Biograph mCT PET/CT scanner for at least 90 min following injection of 427±142 MBq [11C]PBR28. Arterial blood samples were collected to measure the metabolite-corrected input function. Multilinear analysis was used to estimate [11C]PBR28 distribution volumes (VT) in 9 brain regions. Results: In five subjects with available BAC measures, peak levels of 89±21 mg/dL were achieved 90-120 min after initiation of the alcohol session. BAC levels were, on average, 59±14 mg/dL during the PET imaging sessions. Averaged across all subjects and brain regions, the alcohol challenge increased [11C]PBR28 VT by 19% (range, 3%-38%). There was no initial evidence for regional patterns in alcohol’s effects on [11C]PBR28 VT. Conclusions: These preliminary data suggest that [11C]PBR28 VT is sensitive to an oral alcohol challenge in people. Data collection is ongoing to confirm these results in a larger cohort. This imaging approach shows promise for future studies of alcohol-related disorders. References: Sandiego, C.M., et al., 2015. Imaging robust microglial activation after lipopolysaccharide administration in humans with PET. Proc. Nat. Acad. Sci. 112, 12468-12473.