Lone aortic regurgitation, sacroiliitis, and HLA B27. Case history and frequency of association.

An account of aortic regurgitation complicating ankylosing spondylitis is given. Twenty patients with lone aortic regurgitation and without overt spondylitis were examined clinically and radiologically and tissue typed. No evidence of sacroiliitis could be found in any patient. HLA B27 was absent from this group, and no significant disturbance in antigen frequency was noted.