The findings of bamboo spine, dagger sign, syndesmophytes, bilateral sacroiliitis with clinical history are suggestive of ankylosing spondylitis.

Patient's laboratory evaluation shows :

HLA-B27: Positive.

C-Reactive protein: 6.1 (positive).

R.A.Factor : < 20, negative

ESR: 12, raised (0 to 10 normal as per lab standards)