Transplantation antigens in Crohn's disease: Linkage of associated ankylosing spondylitis with HL-Aw27.

The complete HL-A antigen profile was examined in 77 patients with Crohn's disease,11 of whom had unequivocal ankylosing spondylitis. There was no significant difference in the frequencies of the HL-A antigens between these 77 patients and 600 normal controls. 10 male patients with Crohn's disease possessed HL-Aw27; all of these had unequivocal ankylosing spondylitis. This antigen may, therefore, be a useful marker of spondylitis in Crohn's disease.