Ankylosing Spondylitis: An Enigmatic Autoimmune Disorder

Background: Ankylosing spondylitis (AS) is an autoimmune disease that mainly involves spine joints, sacroiliac joints
(SIJs) and their adjacent soft tissues, such as tendons and ligaments. In more advanced cases, this inflammation can
lead to fibrosis and calcification, resulting in the loss of flexibility and the fusion of the spine, resembling “bamboo”
with an immobile position. The main clinical manifestations include back pain and progressive spinal rigidity as well as
inflammation of the hips, shoulders, peripheral joints and fingers/toes. In addition, there are extra-articular
manifestations, such as acute anterior uveitis and inflammatory bowel disease (IBD). AS affects men more often than
women, at a ratio of 2 : 1. The aetiology of AS remains unclear to some extent but studies have revealed some factors
that may be related to the occurrence of AS, including genetic background, immune reaction, microbial infection, and
endocrinal abnormity. The HLA-B27 allele is known to have a strong association with the disease.

Result: The disease mechanisms underlying the disease are not fully understood and there is no treatment that has
been shown to significantly slow the rate of ankylosis or induce disease remission.

Conclusion: Further avenues need to be explored for early diagnosis and effective treatment of AS so that the
socioeconomic burden of AS will be significantly reduced, and patients' suffering will be alleviated.