This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunity, Subject name: Pathology
[{'content': 'HLA B27 is maximally associated with? \nSelect and explain. \nA. Rheumatoid arthritis, B. Ankylosing spondylitis, C. Rieter syndrome, D. Psoriasis', 'role': 'user'}, {'content': "Answer: B \nExplanation: Clinical Associations with HLA B27DisorderHLA-B27 (%)Ankylosing spondylitis90Reactive arthritis (Reither's syndrome )40-80Juvenile SpA70Inflammatory bowel disease35-75Psoriatic arthritisWith spondylitisWith peripheral arthritis 5015Undifferentiated SpA70Acute anterior uveitis50Aortic insufficiency, heart block80", 'role': 'assistant'}]