title: Letter: Histocompatibility testing in doubtful cases of ankylosing spondylitis.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006649:Histocompatibility Antigens; D006650:Histocompatibility Testing; D006801:Humans; D008297:Male; D013167:Spondylitis, Ankylosing / Q000175:diagnosis / Q000276:immunology*
chemical_list: D006649:Histocompatibility Antigens