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Testing for the HLA-B27 allele showed widespread use across specialties and revealed missed opportunities for rheumatology referrals in positive cases. 

A retrospective analysis study published in June 2025 issue of Journal of Rheumatology, researchers examined how HLA-B27 testing has been utilized in routine clinical practice for diagnosing spondylarthritis (SpA). 

They analyzed records of all adults tested for HLA-B27 between January 1, 2022, and December 31, 2022, within the Mass General Brigham healthcare system and recorded demographics, provider specialty, testing indications, and whether tests for antinuclear antibodies (ANA), rheumatoid factor, and/or anticyclic citrullinated peptide antibodies were performed simultaneously. The rheumatology referral rates between HLA-B27–positive and HLA-B27–negative individuals were evaluated and compared.  

The results showed that 1,960 patients (62.4% female; mean age: 47.4 years) underwent HLA-B27 testing, with rheumatology (39.7%) and ophthalmology (21.4%) as the top ordering specialties. Peripheral arthritis (33%), uveitis (22%), and back pain (16.7%) were the leading indications. Concurrent autoantibody testing was done in 69.3% of cases. Overall, 11% of patients tested positive for HLA-B27. Ophthalmology had the highest positivity rate (15.4%), and reactive arthritis showed the highest positivity by indication (50%). Referral to rheumatology occurred more often in patients with positive HLA-B27 (53%) compared to HLA-B27–negative (32%) (P = 0.002). 

Investigators concluded that HLA-B27 testing was widely used across specialties, but referral to rheumatology remained suboptimal even among HLA-B27–positive. 

Source: jrheum.org/content/early/2025/06/11/jrheum.2025-0167