title: Ankylosing spondylitis and its association with the histocompatibility antigen HL-A B27: an epidemiological and clinical study.
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006680:HLA Antigens; D006801:Humans; D007493:Iraq; D008297:Male; D008875:Middle Aged; D013167:Spondylitis, Ankylosing / Q000453:epidemiology / Q000276:immunology*
chemical_list: D006680:HLA Antigens