JAK inhibition prevents the induction of pro-inflammatory HLA-DR+ CD90+ RA synovial fibroblasts by IFNɣ.

HLA-DR+ CD90+ SFs are an activation state that can be induced by IFNɣ, likely provided from infiltrating leukocytes such as activated NK cells. The induction of these pro-inflammatory, IL-6 producing and likely antigen-presenting SFs can be targeted by JAK inhibition.