Multimodal peripheral blood immunophenotyping and single cell epigenetic analysis of knee osteoarthritis reveals expansion and epigenetic dysregulation of regulatory T-cell and nonclassical monocyte populations

The authors aimed to characterize the peripheral blood immunophenotypes and epigenetic landscapes associated with knee osteoarthritis (OA) and its radiographic progressors. Their findings revealed significant expansions of regulatory T-cells and nonclassical monocytes in OA patients, alongside extensive epigenetic remodeling, suggesting that these immune cell changes may be influenced by age and comorbid conditions. The study highlights the complexity of immune responses in OA, indicating a shift towards quiescent, non-migratory cell states despite systemic inflammation.