This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
Which of the following is NOT associated with ankylosing spondylitis: 
Select and explain. 
A. SLE, B. Reiter's syndrome, C. Psoriatic ahropathy, D. Crohn's disease
A: SLE
Answer: A: SLE 
Explanation: Ankylosing spondylitis is an inflammatory disorder of unknown cause Primarily affects the axial skeleton; peripheral joints and extraaicular structuresOlder names: Marie-Strumpell disease or Bechterew's diseaseTypically associated with HLA-B27(ref:Harrison's 18/e p2774, 2775)