Multimodal Molecular Imaging Reveals Tissue-Based T Cell Activation and Viral RNA Persistence for Up to 2 Years Following COVID-19

We assessed immune dysregulation in a group of 24 participants using a novel tracer and whole-body positron emission tomography (PET) imaging. We noted a significant increase in T cell activation in the post-COVID group (those with and without Long COVID) in many anatomical regions. T cells are a type of immune cell that fights cells infected with viruses or other pathogens. We observed that increased activation of these immune cells in the spinal cord and gut wall also correlated with the presence of neurocognitive and gastrointestinal Long COVID symptoms, respectively. Wondering what could be aggravating these immune cells, we asked a subset of 5 imaging participants to undergo a gut biopsy procedure to assess the possible presence of viral persistence – the idea that pieces of the COVID-19 virus may be lurking in the tissues of the body long after the acute infection period has ended which may be contributing to Long COVID symptoms. In all 5 participants, we found RNA (the genetic material) from the COVID-19 virus in the gut tissue, suggesting that this viral material could be associated with long-term immune system disruption.