CD74 and ankylosing spondylitis: We also analyzed the correlation of titer of anti-CD74 and Ankylosing Spondylitis Disease Activity Score-C Reactive Protein (ASDAS-CRP), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), patient global assessment, swelling/pain peripheral joint, morning stiffness, fatigue, levels of back pain, erythrocyte sedimentation rate (ESR) and C reactive protein (CRP).