CRP and arthritic joint disease: To fulfill the ASAS criteria, a minimum of one parameter in the imaging arm or two parameters in the clinical arm should be present, in addition to the following additional Spondyloarthritis features: inflammatory back pain (IBP), arthritis, enthesitis/uveitis, dactylitis, psoriasis, inflammatory bowel disease (IBD), good response to non-steroidal anti-inflammatory drugs (NSAIDs), positive HLA-B27, and increased C-reactive protein (CRP) level.