HLA B27

Autoimmune diseases are those associated with an excessive immune system reaction. During this process, the body’s own tissue is mistaken as foreign and antibodies against the body's own structures are formed. This results in inflammatory reactions of varying degrees. The diseases include inflammations of the small vessels (vasculitis) and the joints (arthritis). The causes of autoimmune diseases are still largely unclear. Infections, stress, pregnancy or the interaction of the intestinal bacteria with the immune system are suspected to be triggering factors. One important and recognised hypothesis assumes predisposition factors. These are genetic traits associated with an increased risk of autoimmune disease. One of them is the human leukocyte antigen B27 (HLA-B27). Due to its polymorphism, it features several subtypes that can lead to the recognition of different antigens. People with expressed HLA-B27 show an increased risk of developing diseases, such as ankylosing spondylitis (Bekhterev's disease), Reiter's disease, psoriatic arthritis, juvenile idiopathic arthritis, rheumatoid arthritis, uveitis, iritis or iridocyclitis.