OP0099 INCREASED FREQUENCY OF CD4+ AND CD8+ FOLLICULAR HELPER T CELLS IN HUMAN LYMPH NODE BIOPSIES DURING THE EARLIEST STAGES OF RHEUMATOID ARTHRITIS

Background Follicular T helper (Tfh) cells provide key help for B cell differentiation into plasma and memory are essential in germinal center formation (auto) antibody generation (1). Objectives To gain more insights the role of Tfh RA development, we assessed whether have an altered frequency, phenotype cytokine profile peripheral blood, lymphoid synovial tissues during earliest stages development. Methods Using flow cytometry, analyzed phenotpe, frequencies blood lymph node biopsies healthy controls (HCs), autoantibody positive individuals at risk developing (RA-risk individuals), early patients. immunofluorescene confirmed presence follicles nodes tissue Results In frequency did not differ between study groups. tissue, were localized B-cell areas, their correlated strongly with CD19 + cells. Compared to controls, that patients RA-risk individuals, showed CD4 CXCR5 CD8 follicular Of note, compared specifically produced less IL-21 upon ex-vivo stimulation. Conclusion localised rich areas The analysis increased cells, where they clearly associate Interestingly, production is already aberrant very phase disease. Our data suggest may present a novel rationale therapeutic targeting preclinical stage prevent further disease progression. References [1]Ise W, Fujii K, Shiroguchi Ito A, Kometani Takeda et al. Helper Cell-Germinal Center Cell Interaction Strength Regulates Entry Plasma or Recycling Germinal Fate. Immunity. 2018;48(4):702-15.e4. Acknowledgements We thank participants study, radiology department Academic Medical (AMC) sampling; cytometry facility Hematology AMC, especially J.A. Dobber; core Cellular Imaging Amsterdam UMC, location AMC. Disclosure Interests Dornatien Anang: None declared, Tamara H.Ramwadhdoebe: Janine Hahnlein: Bo van Kuijk: Smits Noortje: Krijn P. Lienden: Mario Maas: Danielle Gerlag Employee of: UCB Pharma. pharma was involved this Paul-Peter Tak Candel therapeutics. therapeutics Niek de Vries: Lisa Baarsen: declared.