Building a database for brain 18 kDa translocator protein imagedusing 11CPBR28 in healthy subjects

摘要

Translocator protein 18 kDa (TSPO) has been widely imaged as a marker ofneuroinflammation using several radioligands, including [ C]PBR28.In order to study the effects of age, sex, and obesity on TSPO binding and todetermine whether this binding can be accurately assessed using fewer radiohigh-performance liquid chromatography (radio-HPLC) measurements of arterialblood samples, we created a database of 48 healthy subjects who had undergone[ C]PBR28 scans (23 high-affinity binders (HABs) and 25mixed-affinity binders (MABs), 20 F/28 M, age: 40.6 ± 16.8 years). Afteranalysis by Logan plot using 23 metabolite-corrected arterial samples, totaldistribution volume ( ) was found to be 1.2-foldhigher in HABs across all brain regions. Additionally, the polymorphism plotestimated nondisplaceable uptake ( ) as1.40 mL · cm , which generated a specific-to-nondisplaceableratio ( ) of 1.6 ± 0.6 in HABs and 1.1 ± 0.6 inMABs. increased significantly with age in nearlyall regions and was well estimated with radio-HPLC measurements from sixarterial samples. However, did not correlate withbody mass index and was not affected by sex. These results underscore whichpatient characteristics should be accounted for during [ C]PBR28studies and suggest ways to perform such studies more easily and with fewerblood samples.