Ankylosing Spondylitis (849/1700)

A 28yo man is inv for recurrent lower back pain. A dx of AS is suspected. Which of the following inv is most useful?
a. ESR
b. XR sacro-iliac joints
c. HLA B27
d. XR thoracic spine
e. CT lumbar spine



































 answer: B
Sacroilitis on Xray/MRI is the hallmark of AS and required for it's diagnosis
HLA B27 is a non specific investigation