Audit of HLA-B*27 Tests Requested From Jan 2020 to Dec 2024 at the Clinical Transplantation Laboratory

Abstract

Ankylosing spondylitis (AS) is an inflammatory disease characterised by stiffness and fusion of the spine which causes pain, disability, increased healthcare costs and mortality. The pathogenesis of AS is unclear however the presence of HLA-B*27 is strongly associated with developing the disease. A negative B*27 test guides patient treatment. We conducted this audit to investigate the recent increase in B*27 test requests in our laboratory. ClinisysTM PathManager was used to access anonymised data from B*27 samples received between 2020 and 2024. Results from a 6794 tests requests were compared for patient age, gender, ethnicity and sample source. There was an increase in the number of B*27 tests requested between 2020 and 2024. Although there were more tests requested, we did not see a related increase in the number of B*27 positive results. Overall, more samples tested negative for B*27 in 2023 and 2024. More females were tested for B*27 (59.4%) than males (40.6%) but, more males tested B*27 positive (p < 0.001). A significant association between primary and secondary care and B*27 result was found with more positive results in patient sample from secondary care (p < 0.001). Only 47% of samples originated from specialist rheumatology clinics. The difference in B*27 results between primary and secondary care highlights the need for better clinical tools in the treatment of AS. Suggesting that clinical uncertainty in the diagnosis of AS is common despite better disease understanding and updated guidelines.