Are advanced glycation end-product-modified proteins of pathogenetic importance in fibromyalgia?

Objective. To quantify the serum levels of the advanced glycation end-product (AGE) pentosidine in 41 patients with fibromyalgia (FM) and 46 healthy controls. The formation of pentosidine is closely related to oxidative stress. Methods. Pentosidine was measured by reverse-phased high-performance liquid chromatography with gradient separation on a RP-18 column. Results. Patients with FM have significantly higher pentosidine serum levels than healthy subjects. Conclusion. AGE modification of proteins leads to reduced solubility and high resistance to proteolytic digestion of such altered proteins (e.g. AGE-modified collagens). AGES are also able to stimulate different kinds of cells via activation of the NFkappaB, mediated by specific receptors of AGES (e.g. RAGE) on the cell surface. Both mechanisms may contribute to the development, perpetuation and spreading of pain phenomena in FM patients.