Single cell RNA and T‐cell receptor sequencing reveals substantive similarities between synovial fluid and synovial tissue T‐cells in inflammatory arthritis

Synovial fluid (SF)-derived T cells are frequently studied as a proxy for investigating the synovial tissue (ST) T cell infiltrate in inflammatory arthritis. However, because ST is the primary site of inflammatory activity, there is debate as to whether SF provides a true reflection of the ST T cell population.