Rethinking HLA-B27 Testing: What HLA-B27 Can—and Cannot—Tell Us

Article Figures & Data

Table.

Suggested use of HLA-B27 testing.

Specialty	Clinical Context	HLA-B27 Testing	Comments
General practitioner	Chronic back pain in patients aged < 45 years (especially with inflammatory features)	Yes	High pretest probability for axSpA May guide referral decision
	Mechanical back pain	No	Low pretest probability
	Unexplained mono- or oligoarthritis in young patients	Consider	Only in the presence of other SpA features
Rheumatologist	Diagnostic uncertainty in patients with several SpA features	Yes	Might increase diagnostic certainty
	Confirmed axSpA/pSpA already meeting classification criteria	Optional	May provide prognostic value
Ophthalmologist	Recurrent or severe AAU without known cause	Yes	Should prompt rheumatology refererral if positive
Dermatologist	Psoriasis with associated inflammatory musculoskeletal symptoms	Yes	May support diagnosis of psoriatic arthritis
Gastroenterologist	IBD with axial symptoms or peripheral arthritis	Yes	Should prompt rheumatology referral
All specialties	Rheumatologic screening (testing HLA-B27 with ANA, RF, anti-CCP)	No	HLA-B27 should be ordered only when clinically indicated

AAU: acute anterior uveitis; ANA: antinuclear antibody; anti-CCP: anticyclic citrullinated peptide antibody; axSpA: axial spondyloarthritis; IBD: inflammatory bowel disease; pSpA: peripheral spondyloarthritis; RF: rheumatoid factor; SpA: spondyloarthritis.