Ankylosing Spondylitis (AS)

Characteristic symptoms of AS include back pain that is worst in the morning and improves with exercise. AS is more common in men, and patients usually present at a younger age (18-35 years) relative to patients with mechanical causes of back pain or arthritis.

AS is a clinical diagnosis, HLA B27 testing is positive in a large proportion of patients with AS but one should keep in mind that in the general population, about 8% Caucasian, 4% African, 2-9% Chinese, and 0.1-0.5% Japanese have the HLA-B27 antigen.

Commonest cause of death related to AS is renal failure secondary to amyloidosis in AS.