Multiparametric [18F]F-AraG Imaging in Post-Acute Sequelae of COVID-19 (PASC)

Post-acute sequelae of SARS-CoV-2 infection (PASC) is associated with persistent immune dysregulation affecting multiple organ systems. This prospective, non-randomized, open-label research study will apply high-sensitivity total-body PET/CT imaging using the investigational radiotracer \[¹⁸F\]F-AraG to map immune activation across diverse tissues in PASC and COVID-19-recovered control participants. The tracer, \[¹⁸F\]F-AraG, selectively accumulates in activated T cells and allows kinetic modeling of immune cell activity in vivo. A total of 51 participants will be enrolled, including 34 PASC participants and 17 controls. All participants will undergo baseline imaging, and a subset of 17 PASC participants will complete two additional follow-up scans at 4 and 8 months. Each imaging visit includes a dynamic PET/CT scan, peripheral blood draws for plasma proteomics and immunophenotyping, and symptom questionnaires collected through the UCSF LIINC cohort. Findings will be used to identify tissue-specific immune signatures associated with symptom phenotypes and assess how these evolve over time. The results will help clarify the biological basis of PASC and support the development of future diagnostic or monitoring strategies. No direct health benefit is anticipated for participants.