SPECIAL COMMENTARYEmerging synovial cell states in rheumatoid arthritis as potential therapeutic targetsMantel, Ian; Fein, Miriam R.; Donlin, Laura T. Author Information aWeill Cornell Medicine Graduate School bHospital for Special Surgery Research Institute, New York, New York, USA Correspondence to Laura T. Donlin, Hospital for Special Surgery Research Institute, 535 East 70th St, New York, NY 10021, USA. Tel: +1 212 774 2743; e-mail: [email protected] Current Opinion in Rheumatology 35(4):p 249-254, July 2023. | DOI: 10.1097/BOR.0000000000000940 Buy Metrics Abstract Purpose of review To summarize recently discovered novel cell states in rheumatoid arthritis (RA) synovium that could have important implications for disease treatment. Recent findings The use of multiomic technologies, including single-cell and spatial transcriptomics and mass cytometry, has led to the discovery of several novel cell states, which could have important implications for the treatment of RA. These cells can be found in patient blood, synovial fluid, or synovial tissue and span several immune cell subsets as well as stromal cell types. These diverse cell states may represent the targets of current or future therapeutics, while their fluctuations may inform the ideal timing for therapy. Future efforts are needed to implicate how each cell state functions in the pathophysiologic network within affected joints and how medications perturb each cell state and ultimately the tissue. Summary Multiomic molecular technologies have afforded the discovery of numerous novel cellular states in RA synovium; the next challenge will be to link these states to pathophysiology and treatment response. Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.