Scientists at deCODE genetics a subsidiary of Amgen report in Arthritis & Rheumatology that the level of cartilage acidic protein-1 (CRTAC1) in plasma is a potential biomarker of osteoarthritis (OA) through its association with OA risk and progression to joint replacement. The level of CRTAC1 in plasma was recently associated with osteoarthritis (OA) risk and progression to joint replacements in Iceland. The new study was undertaken in the large UK Biobank resource to determine if this also is true for individuals from the United Kingdom. The scientists have now identified CRTAC1 as a promising biomarker of OA with support from two different populations.
The results show that CRTAC1 associates with both prevalent and incident knee and hip OA, and predicts progression to joint replacements in this populations. Of the 1462 proteins measured in plasma from over 54,000 individuals CRTAC1 is the strongest predictor of OA. Individuals in the highest quintile of risk based on CRTAC1, age, sex, and BMI, have a tenfold risk of knee or hip OA within 5 years of those in the lowest quintile. Importantly, as in Iceland, no association was found with inflammatory joint diseases, thus making CRTAC1 a specific biomarker of OA.
The lack of a biomarker of osteoarthritis (OA) has hindered the development of effective therapies for this common disease. No measures are presently available for early diagnosis of OA before destructive changes are observable on radiographs, and no disease-modifying drugs are marketed for OA. This biomarker that is associated with disease occurrence and/or progression may help to identify those at risk for the disease earlier and monitor the disease course.
