title: The presence of HLA-B27 may be misleading.
mesh_terms: D000328:Adult; D001416:Back Pain / Q000175:diagnosis*; D003937:Diagnosis, Differential; D006680:HLA Antigens / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D011859:Radiography; D012446:Sacroiliac Joint / Q000000981:diagnostic imaging; D013167:Spondylitis, Ankylosing / Q000175:diagnosis*
chemical_list: D006680:HLA Antigens