Histocompatibility antigens in vertebral ankylosing hyperostosis.

All known A, B, and C HLA antigens were determined in 50 white patients with vertebral ankylosing hyperostosis. A statistically significant decrease was found for the A9 and A11 specificities. Only three (6%) of the patients possessed the B27 antigen, a frequency which is not different from that of a control population. B27 therefore does not seem to be linked to abundant new bone formation.