The Frequency of HLA-B27 Antigen Positivity in Patients with Rheumatoid Arthritis and Anklylosing Spondylitis and The Relationship Between HLA-B27 Antigen and Other Autoantibodies

Abstract

Objective: The aim of this study was to research the frequency of Human Leukocyte Antigen (HLA)-B27 antigen positivity and relationship between HLA-B27 positivity and other autoantibodies and between HLA-B27 positivity and treatment in patients diagnosed with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). Material and Method: The study is a retrospective study. Patients diagnosed with RA and AS as a result of the examinations performed at Physical Medicine and Rehabilitation outpatient clinic between January 2017 and September 2022 were retrospectively screened, and patients whose HLA-B27 antigen was tested were included in study. Results: A total of 569 patients, 199 with RA and 370 with AS were included in study. While HLA-B27 was positive in 11% of patients with RA, it was 37.5% in patients with AS and there was a significant difference between the groups. When we analyzed the correlation of autoantibodies with HLA-B27, we found that HLA-B27 was not correlated with RF, Anti-cyclic citrullinated peptides (Anti-CCP) or Anti-nuclear antibody (ANA). When we analyzed the relationship between HLA-B27 and the treatment method, there was no significant relationship between HLA-B27 and treatment method. Conclusion: While HLA-B27 was found to be 5% positive in the general population in the literature, we found 11% in 199 patients with RA. This study is important because it shows that HLA-B27 positivity is not very common in patients diagnosed with AS recently contrary to popular belief. More studies are needed to evaluate HLA-B27 frequency in RA and AS.