From the Research
There is a strong association between HLA-B27 and the development of Reiter syndrome, with approximately 60-80% of patients with Reiter syndrome testing positive for the HLA-B27 genetic marker, compared to only about 8% of the general population. This association is supported by several studies, including one published in 1999, which found that an HLA-B27 genotype is a predisposing factor in over two thirds of patients with reactive arthritis 1. Another study published in 2008 noted that the disease is more common in men, and that the pathophysiology has yet to be elucidated, although infectious and immune factors are likely involved 2. The presence of HLA-B27 appears to predispose individuals to an abnormal immune response after certain bacterial infections, leading to the classic triad of symptoms: arthritis, conjunctivitis, and urethritis.
Some key points to consider include:
- The HLA-B27 genetic marker is located on chromosome 6 and plays a role in immune system function
- Reiter syndrome typically develops following certain bacterial infections, particularly those affecting the genitourinary tract (like chlamydia) or gastrointestinal tract (like salmonella, shigella, campylobacter, or yersinia)
- Testing for HLA-B27 can be helpful in diagnosing Reiter syndrome, especially in patients with incomplete symptom presentation, but it is not required for diagnosis as clinical features remain the primary diagnostic criteria
- While having the HLA-B27 marker increases risk, not everyone with this genetic marker will develop the condition, and some people without it can still develop reactive arthritis
It's worth noting that the study published in 1986 found no evidence of molecular mimicry between HLA B27 and two organisms implicated in reactive arthritis, Yersinia enterocolitica and Chlamydia trachomatis 3. However, this study does not negate the association between HLA-B27 and Reiter syndrome, but rather suggests that the relationship between HLA-B27 and reactive arthritis may be more complex than previously thought.
In terms of treatment, the study published in 1999 recommended initial treatment with high doses of potent nonsteroidal anti-inflammatory drugs, and noted that patients with large-joint involvement may also benefit from intra-articular corticosteroid injection 1. Overall, the association between HLA-B27 and Reiter syndrome is well-established, and testing for HLA-B27 can be a useful diagnostic tool in certain cases.