YKL-40 in health and disease: a challenge for joint inflammation

There is a need of biomarkers to detect early joint inflammation and destruction of cartilage in different types of arthritis. YKL-40, a 39 kD heparin- and chitin-binding secreted glycoprotein (also known as cartilage gp39), was recently discovered. Its exact biological function is still unclear. Specific receptors for YKL-40 have not been identified yet. The clinical significance of YKL-40 as a biomarker is discussed in different aspects. High level of YKL-40 was found in various human diseases associated with inflammatory and neoplastic processes. The review highlights the information available about YKL-40 and its significance in inflammatory joint diseases. We suggest that this glycoprotein might have a promising value as a novel biomarker and could provide additional evidence for inflammation activity in different types of arthritis. Biomedical Reviews 2013, 24: 49-56.