CRP and ankylosing spondylitis: ASDAS-CRP: Ankylosing Spondylitis Disease Activity Score-C-reactive protein; BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; BASFI: Bath Ankylosing Spondylitis Functional Index; VAS-F: Visual Analogue Scale-Fatigue; * p value ≤ 0.05