is a gene which has a much higher positive prevalence in certain auto-immune/autoinflammatory diseases such as Spondyloarthritis, Uveitis/Iritis, Crohns Disease, Ulcerative Colitis and Psoriasis. Positive HLA-B27 affects people in multiple ways, when it comes to Spondyloarthritis in related to musculoskeletal (MSK). Approximately 90% (male) and 85% (female) positivity in AxSpA Approximately 40-50% positivity in Psoriatic Arthritis (PsA).
The prevalence of HLA-B27 positivity in the general population is around 8-12% although its frequency is lower in African American, South American and Middle Eastern populations than in others.HLA-B27 is the most important genetic factor for development risk of Axial spondyloarthritis (AxSpA) but there are other implicated genetic markers, all of which do vary for different populations.
Under-representation of the groups with lower HLA-B27 positivity in research and epidemiology is an issue and inclusion of these groups could provide information on other subsets. Don’t over rely on HLA-B27 in clinical practice, the interplay of the complicating factors of axial vs peripheral, population variations and HLA-B27 negative Spondyloarthritis means that interpretation is best left to Rheumatologists.
