This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Musculoskeletal  disorders, Subject name: Pediatrics
[{'content': 'The common HLA type associated with Behcet disease is _________ \nSelect and explain. \nA. HLA DR4, B. HLA B27, C. HLA B51, D. HLA CW6', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Behcet disease is associated with HLA haplotype B51 in paicular. Behcet disease is a neutrophilic vasculitis affecting small to medium-sized vessels that classically presents as a clinical triad of recurrent oral aphthous ulcers, genital ulcers, and uveitis. Here (Th17) T helper 17 cells play an impoant contribution in recruitement of neutrophils, which will later infiltrate into the vessel wall. There can also be gastrointestinal and pulmonary manifestations, with disease moality related to severe neurologic involvement or rupture of vascular aneurysms. Reference : nelson textbook of pediatrics 21st edition Pgno: 1289', 'role': 'assistant'}]