The close correlation between symptoms and disease expression in HLA B27 positive individuals.

Following demonstration that 20 percent of presumed "healthy" HLA B27 positive individuals develop symptomatic ankylosing spondylitis, a controlled follow-up assessment of the remaining "asymptomatic" 80 percent was performed. The clinical and radiological study revealed that there is a close correlation between symptoms and radiologic change in HLA B27 positive subjects; those individuals remaining symptom free have normal pelvic radiographs. Ankylosing spondylitis or "asymptomatic sarcroiliitis" does not exist in a subclinical manner throughout the entire group of B27 positive subjects. Evaluation of the pelvic radiographs of both symptomatic and asymptomatic HLA B27 positive subjects and symptomatic HLA B27 negative controls demonstrated that osteitis pubis and fluffy periostitis are equally distributed among the three groups, only the frequency of sacroiliitis being statistically greater in the B27 positive symptomatic subjects.