Keratan sulfate as a potential biomarker of loading of the intervertebral disc.

Abstract

A review of the literature. To investigate the potential of serum levels of keratan sulfate as a biomarker of the effects of loading of the spine. Exposure to mechanical loading of the spine causes changes in metabolism of intervertebral discs, eventually leading to accelerated disc degeneration. This process is characterized by the degradation of proteoglycans, which is reflected by an increase in the blood level of proteoglycan components. The serum level of keratan sulfate, an epitope present on these proteoglycan components, has been suggested as a marker of changes in metabolism of cartilaginous tissues. A review of the literature on serum keratan sulfate levels in relation to degenerative changes in cartilaginous tissue. In a number of studies keratan sulfate in serum was reported to be related to degeneration of articular cartilage in patients with osteoarthritis. In addition, massive and rapid degradation of intervertebral discs was determined to result in a large rise in serum keratan sulfate levels. Whether degenerative changes of intervertebral discs induced by mechanical stress also cause a detectable increase in serum keratan sulfate should be subjected to further investigation. Quantification of keratan sulfate in serum offers a promising measure for the early effects of mechanical loading of the spine, but research is needed for validation.