Abstract
Rheumatoid arthritis is a chronic inflammatory autoimmune disease typically affecting the synovial membrane, leading to pannus formation due to interaction among stromal and inflammatory cells and angiogenesis. Calprotectin is an S100A8/S100A9 heterodimer produced by activated neutrophils, monocytes, and macrophages in inflammatory tissue and circulation.
In patients with RA, it is mainly produced locally in affected joints promoting inflammation, cartilage destruction, and bone resorption. Calprotectin can be detected in the circulation and used as a soluble biomarker.
It appears to be a better marker of disease activity than typically used acute phase reactants; moreover, it can be used as a predictive marker of radiographic progression, therapeutic response, and disease flare.