HLA-B27 Testing in Practice Save

Analysis of testing for human leukocyte antigen B27 (HLA-B27) in a teaching center shows HLA-B27 testing was frequently performed by rheumatologists and nonrheumatologists for a broad spectrum of indications and primarily as a screening test. 

Data derived from the Mass General Brigham healthcare system, examined HLA-B27 testing and clinical associations between 1/1/2022 to 12/31/2022. Rheumatology referrals  were calculated for HLA-B27 positive and negative patients.

HLA-B27 tests was ordered in 1960 patients (62.4% female, average age 47.4 years).  A total of 10.9% of HLA-B27 tests were positive. 

The most common specialties testing for HLA-B27 were rheumatology (39.7%) and ophthalmology (21.4%). 

The most common indications for HLA-B27 testing were peripheral arthritis (33.0%), uveitis (22.0%), and back pain (16.7%). 

The majority of HLA-B27 tests (69.3%) were ordered concurrently with other autoantibody tests. Ophthalmology had the highest positive rate (15.4%) while reactive arthritis was the indication with the highest positive test rate (50%). 

Patients who were HLA-B27 positive were more likely to be referred to rheumatology (53% vs 32%, p=0.002).

Some odd findings were that HLA-B27 is often ordered with tests for ANA and rheumatoid arthritis.  Also half of HLA-B27 positive patients were not referred to rheumatology.