CRP and ankylosing spondylitis: Targeted inhibition of TNF-α/IL-6 signaling may represent a novel therapeutic strategy for retarding RA progression.[21] Jing et al reported significantly elevated serum levels of IL-6 and TNF-α in patients with AS, which were strongly correlated with disease activity (Bath Ankylosing Spondylitis Disease Activity Index), inflammatory markers (CRP, ESR), and imaging grading of sacroiliac joints.