[Biomarker of bone and cartilage destruction in rheumatoid arthritis].

Recent progress in treatment and imaging enables us to aim the clinical remission in rheumatoid arthritis. In terms of achieving deep remission (structural remission) and predicting prognosis, useful serological biomarkers are now expected. Recently, some of the serological biomarkers, such as RANKL (receptor activator of NF-κB ligand) and TRACP (tartrate-resistant acid phopshatate)-5b, are used to assess the activity of rheumatoid arthritis. The levels of these biomarkers well reflect bone erosion but are less affected by age or physiological variation.