From the Guidelines
HLA-B is strongly associated with certain diseases, particularly those related to immune system function and autoimmune disorders. The HLA-B gene plays a crucial role in presenting antigens to immune cells, and specific alleles have been linked to various diseases. For example, HLA-B27 is closely associated with the severity and persistence of axial spondyloarthropathies, as noted in a 2019 study published in Autoimmunity Reviews 1. Other HLA-B alleles, such as HLA-B51, have been linked to Behçet disease, a small vessel vasculitis that can involve veins and arteries, as described in a 2010 guideline published in Circulation 1. Key points to consider include:
- HLA-B27 is associated with ankylosing spondylitis, reactive arthritis, and other spondyloarthropathies
- HLA-B51 is linked to Behçet disease, a small vessel vasculitis
- HLA-B alleles can predispose individuals to abnormal immune responses and disease
- Clinicians use HLA typing to assess disease risk and guide medication choices in susceptible populations. In clinical practice, it is essential to consider HLA-B associations when diagnosing and managing patients with autoimmune disorders or those at risk of adverse reactions to certain medications, as highlighted in the 2019 study 1.
From the Research
HLA-B Association with Diseases
- HLA-B27 is associated with ankylosing spondylitis (AS), a highly heritable disease, and is found in approximately 60%-90% of axial spondyloarthritis (axSpA) patients worldwide 2.
- The prevalence of AS is linked to the frequency of HLA-B27 in the population, implying relevant differences 2.
- HLA-B27 also plays a crucial role in the classification, diagnosis, and severity of axSpA 2.
Clinical Features of HLA-B27-Associated Diseases
- HLA-B27 is positively associated with AS, particularly in males, and is linked to a higher risk of uveitis, peripheral joint involvement, and hip joint involvement 3.
- The presence of HLA-B27 is associated with a younger age of onset, shorter delay in diagnosis, and better clinical response to tumor necrosis factor inhibitors in AS patients 4.
- HLA-B27 is also associated with a greater risk of acute anterior uveitis and a lower risk of psoriasis and inflammatory bowel disease (IBD) in AS patients 4.
HLA-B27 and Autoimmune Diseases
- Spondyloarthropathies (SpA) associated with HLA-B27 are often classified as autoimmune diseases, but the evidence for this classification is questionable 5.
- A study found no significant difference in autoreactivity between SpA patients and controls, suggesting that SpA may not be an autoimmune disease attributable to crossreactivity between bacteria and HLA-B27 5.