Relationship of HS CRP and Sacroiliac Joint Inflammation in Undifferentiated Spondyloarthritis

OBJECTIVE: Elevation of serum high sensitivity C-reactive protein (hs-CRP) level has been demonstrated as a risk factor for varying diseases, as well as a biomarker for predicting recovery after operation of lumber disc herniation. Our objective was to investigate the relationship between serum hs-CRP and sacroiliac (SI) joint inflammation in patients with undifferentiated spondyloarthritis (uSpA). METHODS: In this retrospective study, we enrolled patients with uSpA who underwent hs-CRP testing between January 2007 and September 2013. Serum hs-CRP was analyzed at our central laboratory. All enrolled patients underwent skeletal scintigraphic scan with quantitative sacroiliac measurement. RESULTS: A total of 29 patients were enrolled with mean age 32.27 years and female:male ratio of 6:23. Pearson’s correlation coefficient showed a significant difference between hs-CRP in serum and SI/S ratio in uSpA, particularly the middle part of the sacroiliac joint, either right side or left side. The significantly high concentration of serum hs-CRP might indicate a systemic inflammatory response to flare-up of the SI joint and might be an indicator of SI inflammation in uSpA.