I often see patients in the clinic holding up labs and telling me “Doctor, I have ankylosing spondylitis”, but when I look at the labs in their hands, it is only a positive HLA-B27 test result, and when I ask about the symptoms and check the signs, there is nothing special. Is it necessarily ankylosing spondylitis? Domestic and international epidemiological data show that HLA-B27 positivity does not necessarily mean that you have ankylosing spondylitis. Although more than 90% of patients with ankylosing spondylitis are HLA-B27 positive, less than 50% of those with HLA-B27 positive have ankylosing spondylitis, so HLA-B27 positivity does not necessarily mean that you have ankylosing spondylitis, and so far, HLA-B27 positivity has not been used as evidence to confirm the diagnosis in the diagnostic criteria of various countries, but only as one of the main reference indicators.