HLA-B27 and the role of specific T cell receptors in the pathogenesis of spondyloarthritis
The pathogenesis of axial spondyloarthritis (axSpA), although not entirely clear yet, is largely based on genes, the strongest association being with HLA-B27, importantly also in connection with aminopeptidase ERAP 1 polymorphisms. Peptides potentially derived from microbes and/or autoantigens presented by HLA-B27 expressed on antigen-presenting cells to CD8+T cells are thought to play a critical role. Studies in HLA-B27 positive patients with AS and reactive arthritis over the last decades have pointed towards a clonal expansion of CD8+T cells with similar and shared T cell receptors (TCR) suggestive of binding antigens with a common motif. This offers the therapeutic option of inhibiting or eliminating selected TCR. Indeed, a recent report on an axSpA patient who was treated with an antibody to the TCR TRBV9 has suggested that this intervention may be successful. Radiographic axial spondyloarthritis (axSpA), which is largely equivalent to ankylosing spondylitis (AS), is a frequent in