Cioffi, M.

De Filippo, G.

Insabato, L.

Mossetti, G.

Rendina, D.

Sorrentino, M.

Strazzullo, P.

Zampa, G.

Scientific Open-access Literature Archive and Repository

OSTEOPROTEGERIN/RANKL SYSTEM AND BONE TURNOVER MARKERS IN ONCOGENIC HYPOPHOSPHATEMIC OSTEOMALACIAD. Rendina1, G. De Filippo2, M. Sorrentino1, G. Zampa1, L. Insabato4, M. Cioffi3, P. Strazzullo1, G. Mossetti11 Department of Clinical and Experimental Medicine, Federico II University Medical School, Naples, Naples, Italy2 Unit of Paediatric Endocrinology, A.O.R.N. “G. Rummo”, Benevento, Benevento, Italy3 Department of Clinical Pathology, II Medical School, Naples University, Naples, Italy4 Department of Functional and Morphological Sciences, Section of Pathology, Federico II University Medical School,Naples, Naples, Italy Oncogenic hypophosphatemic osteomalacia (OHO) is a rare paraneoplastic syndrome characterised byelevated fibroblast growth factor 23 (FGF-23) serum levels, hypophosphataemia, urinary phosphate wast-ing and deranged skeletal metabolism. Characteristically, 25-hydroxyvitamin D and 1,25-dihydroxyvitaminD concentration are also generally overtly low or inappropriately normal relative to the prevailing hy-pophosphataemia.Aims of this study were to evaluate serum levels of components of osteoprotegerin (OPG) system andtheir relationship with bone mineral density and bone turnover markers (bone specific alkaline phos-phatase, cross-linked C-telopeptide of collagen type 1 and urinary hydroxyproline/creatinine ratio) in fivepatients with OHO (M:F 3:2; mean age 56.6±3.7 years). The “reference values” of evaluated parameterswere determined in 40 age- and sex- matched healthy control subjects.OHO patients showed serum levels of ligand of receptor activator of nuclear factor (NF)-κB (RANKL) sig-nificantly lower compared to healthy controls (0.52±0.19 vs 1.05±0.23 pmol/L, p 0.024). Bone alkalinephosphatase serum levels in OHO patients were also significantly higher compared to controls (42.8±17.5vs 17.5±6.7 µg/L, p<0.001). FGF23 serum levels in OHO patients were directly related to L2-L4 BMD (r=-0.724, p=0.014). Levels of OPG and other bone turnover markers were not different between studygroups. One year after the complete surgical excision of neoplastic lesions causing OHO in two patients,the reported parameters were within the normal range. Study results suggest that bone loss during OHO is not related to biological properties of RANKL/OPGsystem, but could be caused directly by FGF23. In this contest, the functional inhibition of RANKL/OPGsystem and the increased bone specific alkaline phosphatase serum levels could be considered a com-pensatory mechanism to bone loss.Clinical Cases in Mineral and Bone Metabolism 2005; 2(3): 185-252 237BSTR CT (V Congresso CCMBM)  18/11/2005  15.59  Pagina 237FOR REVIEW ONLY© CIC EDIZIONI INTERNAZIONALI

Osteoprotegerin/Rankl system an bone turnover markers in oncogenic hypophosphatemic osteomalacia

http://eprints.bice.rm.cnr.it/9051/1/article.pdf

Osteoprotegerin/Rankl system an bone turnover markers in oncogenic hypophosphatemic osteomalacia

Abstract

Similar works

Full text

Available Versions

Scientific Open-access Literature Archive and Repository