CRP and ankylosing spondylitis: DAS28 CRP: Disease Activity Score in 28 Joints using C-reactive Protein; CDAI: Clinical Disease Activity Index; SDAI: Score Disease Activity Index; HAQ: Health Assessment Questionnaire; ASDAS CRP: Ankylosing Spondylitis Disease Activity Score using C-reactive Protein; BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; BASFI: Bath Ankylosing Spondylitis Functional Index; RA: rheumatoid arthritis; SpA: spondyloarthritis