Purpose of review: We focus on the role of killer immunoglobulin receptor (KIR) interactions with the human leukocyte antigens (HLA)-B27 ligand and the potential contribution of KIR-expressing natural killer and T cells in spondyloarthritis, more specifically in ankylosing spondylitis (AS).
Recent findings: In AS strong epidemiological evidence of significant genetic associations with the major histocompatibility complex was convincingly identified. HLA-B27-positive first-degree relatives of AS cases are 5-16 times more likely to develop disease than HLA-B27-positive carriers in the general community. The GWAS era has enabled rapid progress in identifying non-major histocompatibility complex associations of AS.
Summary: These findings show a number of important pathways in AS pathogenesis, including the IL-23-IL-17 pathway, aminopeptidases, peptide presentation, and KIR-HLA-B27 interactions. Studies using genetic markers, including KIRs may be used for a risk assessment about whom may benefit most from the various treatment protocols in spondyloarthritis, now that alternative therapeutic options have become feasible.