OPG/RANKL system imbalance in a case of hepatitis C-associated osteosclerosis: the pathogenetic key?

Clin Rheumatol. 2005 Jun;24(3):296-300. doi: 10.1007/s10067-004-1031-3. Epub 2004 Dec 4.

Abstract

Hepatitis C-associated osteosclerosis (HCAO) is an impressive example of acquired diffuse osteosclerosis in adults, recently described in ten patients infected with hepatitis C virus (HCV). Its hallmark is a painful and generalized increase of bone mass. Bone biopsies show enhanced accretion rate, usually without histological abnormalities. The HCAO pathogenesis is hitherto unknown. HCV might induce a slow bone cell infection and the production of bone growth factors, such as insulin-like growth factors. Recently, receptor activator of nuclear factor-kappaB (RANK), its ligand (RANKL), and soluble decoy receptor osteoprotegerin (OPG) have been identified as a pivotal cytokine system in the bone remodeling control. We describe the 11th case of HCAO. Notably, the patient's bone biopsy showed the presence of a high number of OPG-positive osteoblasts, a slight increase of RANKL-positive stromal cells, and a dramatic reduction of the osteoclasts. Moreover, OPG serum levels were increased. These findings reported here for the first time are consistent with a pathogenetic role of the OPG/RANKL system imbalance in HCAO.

Publication types

  • Case Reports

MeSH terms

  • Absorptiometry, Photon
  • Aged
  • Biomarkers / metabolism
  • Biopsy
  • Bone Density
  • Bone Remodeling / physiology*
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / pathology
  • Carrier Proteins / metabolism*
  • Diagnosis, Differential
  • Enzyme-Linked Immunosorbent Assay
  • Glycoproteins / metabolism*
  • Hepacivirus* / genetics
  • Hepacivirus* / immunology
  • Hepatitis C Antibodies / analysis
  • Humans
  • Immunoblotting
  • Ligands
  • Male
  • Membrane Glycoproteins / metabolism*
  • Osteoblasts / metabolism
  • Osteoprotegerin
  • Osteosclerosis / diagnosis
  • Osteosclerosis / metabolism*
  • Osteosclerosis / virology*
  • RANK Ligand
  • RNA, Viral / analysis
  • Radionuclide Imaging
  • Receptor Activator of Nuclear Factor-kappa B
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Receptors, Tumor Necrosis Factor / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Biomarkers
  • Carrier Proteins
  • Glycoproteins
  • Hepatitis C Antibodies
  • Ligands
  • Membrane Glycoproteins
  • Osteoprotegerin
  • RANK Ligand
  • RNA, Viral
  • Receptor Activator of Nuclear Factor-kappa B
  • Receptors, Cytoplasmic and Nuclear
  • Receptors, Tumor Necrosis Factor
  • TNFRSF11A protein, human
  • TNFRSF11B protein, human
  • TNFSF11 protein, human