CRP and arthritic joint disease: The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level may be mildly elevated, particularly in cases featuring arthritis, erythema nodosum-like lesions, or vascular issues, but no autoantibody such as rheumatoid factor or antinuclear, anticardiolipin, or antineutrophil cytoplasmic antibody (ANCA) is typically detected.