How is HLA B27 associated with anterior uveitis?
In Western populations, acute anterior uveitis (AAU) is associated with HLA-B27 in 50% of patients. This group can be further subdivided into isolated HLA-B27-associated anterior uveitis (20%–50%) and those associated with an underlying spondyloarthritis (50%–80%; higher estimates of 80% identified in recent studies utilizing the Assessment of Spondyloarthritis International Society criteria for spondyloarthritis). Patients with HLA-B27-positive AAU are more likely to be Caucasian, younger, male sex, have an acute course, experience recurrences, develop hypopyon (the most common cause of hypopyon-complicated uveitis in North America), and have an associated systemic disease than patients with HLA-B27-negative AAU.
| HLA-B27-Associated Disease | % of SpA Patients Developing AAU | % of all AAU Patients Developing SpA | % of HLA-B27+ AAU Patients Developing SpA |
|---|---|---|---|
| Ankylosing spondylitis | 20–40 | 15–50 | 55–90 |
| Reactive arthritis | 10–20 | 2–25 | 8–21 |
| PsA | 7–10 | 0–2 | 3–4 |
| Enteropathic arthropathy | 2–9 | 2–3 | 1–7 |
| Undifferentiated SpA | – | 4–12 | 5–21 |
