Circulating mature granzyme B+ T cells distinguish Crohn's disease-associated axial spondyloarthritis from axial spondyloarthritis and Crohn's disease.

Our findings support the presence of a chronic interferonopathy in subjects with CD-axSpA characterized by interferon signaling by pathway analysis and an expansion of mature, cytotoxic T cells. These data indicate fundamental immunological differences between CD-axSpA and both of the putative "parent" conditions, suggesting that it is a distinct disease with unique natural history and treatment needs.