Biomarkers in spondyloarthropathies

The study of biomarkers in spondyloarthropathy (SpA) has emerged to be a very important field of research. This is particularly because the two commonly used biomarkers, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), are of very low sensitivity and specificity. The second reason is, with advances in the treatment of SpA by the very expensive tumor necrosis factor-alpha (TNF-alpha) blockers, for cost-effectiveness, clinicians need to be much more accurate in predicting disease progression, evaluating disease activity and monitoring therapeutic efficacy. This review focuses on several biomarkers of promise: matrix metalloproteinases 3 (MMP-3), Type II collagen neoepitope (C2C and C1-2C), C-propeptide of Type II collagen (CPII), aggrecan 846 epitope, macrophage colony stimulating factor (M-CSF), serum amyloid A (SAA) and Interleukin-6 (IL-6). The results summarized in Table 1 call for a co-ordinated effort for systematic studies of existing biomarkers and for search for new candidates.