This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
Thromboangitis obliterans is associated with 
Select and explain. 
A. HLA - DR4, B. HLA - DR2, C. HLA - B5, D. HLA - B27
C: HLA - B5
Answer: C: HLA - B5 
Explanation: HLA A9 and HLA B5 is associated with increased risk of Thromboangitis obliterans (TAO) HLA-B12 is protective against TAO.