In Vivo PET Imaging of the Activated Immune Environment in a Small Animal Model of Inflammatory Arthritis MOLECULAR IMAGING Franc, B. L., Goth, S., MacKenzie, J., Li, X., Blecha, J., Lam, T., Jivan, S., Hawkins, R. A., VanBrocklin, H. 2017; 16: 1536012117712638


Evolving immune-mediated therapeutic strategies for rheumatoid arthritis (RA) may benefit from an improved understanding of the complex role that T-cell activation plays in RA. This study assessed the potential of fluorine-18-labeled 9-ß-d-arabinofuranosylguanine ([18F]F-AraG) positron emission tomography (PET) imaging to report immune activation in vivo in an adjuvant-induced arthritis (AIA) small animal model.Using positron emission tomography-computed tomography imaging, uptake of [18F]F-AraG in the paws of mice affected by arthritis at 6 (acute) and 20 (chronic) days following AIA induction in a single paw was assessed and compared to uptake in contralateral control paws. Fractions of T cells and B cells demonstrating markers of activation at the 2 time points were determined by flow cytometry.Differential uptake of [18F]F-AraG was demonstrated on imaging of the affected joint when compared to control at both acute and chronic time points with corresponding changes in markers of T-cell activation observed on flow cytometry.[18F]F-AraG may serve as an imaging biomarker of T-cell activation in inflammatory arthritis. Further development of this technique is warranted and could offer a tool to explore the temporal link between activated T cells and RA as well as to monitor immune-mediated therapies for RA in clinical trials.

View details for DOI 10.1177/1536012117712638

View details for Web of Science ID 000403887800001

View details for PubMedID 28625080

View details for PubMedCentralID PMC5480631