Analysis of circulating osteoclast and osteogenic precursors in patients with gorham-stout disease

PurposeGorham-Stout disease is a very rare disorder characterized by progressive bone erosion and angiomatous proliferation; its etiopathogenesis is still unknown, and diagnosis is still performed by exclusion criteria. The alteration of bone remodeling activity has been reported in patients; in this study, we characterized circulating osteoclast and osteogenic precursors that could be important to better understand the osteolysis observed in patients.MethodsFlow cytometry analysis of PBMC (Peripheral Blood Mononuclear Cells) was performed to characterize circulating osteoclast and osteogenic precursors in GSD patients (n = 9) compared to healthy donors (n = 55). Moreover, ELISA assays were assessed to evaluate serum levels of bone markers including RANK-L (Receptor activator of NF-kappa B ligand), OPG (Osteoprotegerin), BALP (Bone Alkaline Phosphatase) and OCN (Osteocalcin).ResultsWe found an increase of CD16-/CD14+CD11b+ and CD115+/CD14+CD11b+ osteoclast precursors in GSD patients, with high levels of serum RANK-L that could reflect the increase of bone resorption activity observed in patients. Moreover, no significant alterations were found regarding osteogenic precursors and serum levels of BALP and OCN.ConclusionThe analysis of circulating bone cell precursors, as well as of RANK-L, could be relevant as an additional diagnostic tool for these patients and could be exploited for therapeutic purposes.