title: Osteoclast-like multinucleated giant cells in sinonasal inflammation of granulomatosis with polyangiitis (Wegener's granulomatosis).
abstract: OBJECTIVE
  To determine whether generation of osteoclast-like multinucleated giant cells (MNG) is a general feature of granulomatosis with polyangiitis (GPA).
  
  
  METHODS
  MNG phenotype of GPA sinus was examined by immunohistochemistry using antibodies against CD68, and cathepsin K. Tartrate resistant acid phosphatase (TRAP) expression was assessed by enzymatic color reaction. Effects of bacterial wall components peptidoglycan (PGN) or lipoteichoic acid (LTA) on TRAP + MNG formation were determined.
  
  
  RESULTS
  Tissue infiltrating MNGs in sinus expressed CD68, TRAP, and cathepsin K. They were strikingly less frequent in sinus than in lung lesions (23.1% vs. 70%, p=0.04). PGN and LTA inhibited MNG formation in a dose-dependent manner.
  
  
  CONCLUSIONS
  While the generation of osteoclast-like MNGs is an intrinsic feature of GPA, MNGs are rare in sinonasal GPA lesions. Inhibition of MNG formation by bacterial cell wall components may occur preferentially in this sinonasal microenvironment, and contribute to these striking regional pathological differences.
authors: Division of Rheumatology, Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea. jinkyunpark@gmail.com
authors: J K
authors: JK
authors: Park
authors: F
authors: F
authors: Askin
mesh_terms: D000135:Acid Phosphatase / Q000378:metabolism; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D056657:Cathepsin K / Q000378:metabolism; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015726:Giant Cells / Q000187:drug effects / Q000276:immunology / Q000473:pathology*; D014890:Granulomatosis with Polyangiitis / Q000276:immunology / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008168:Lung / Q000276:immunology / Q000473:pathology; D010010:Osteoclasts / Q000187:drug effects / Q000276:immunology / Q000473:pathology*; D010256:Paranasal Sinuses / Q000187:drug effects / Q000276:immunology / Q000473:pathology*; D010457:Peptidoglycan / Q000494:pharmacology; D010641:Phenotype; D012852:Sinusitis / Q000276:immunology / Q000473:pathology*; D000071681:Tartrate-Resistant Acid Phosphatase; D013682:Teichoic Acids / Q000494:pharmacology; D000097382:CD68 Molecule
chemical_list: D000135:Acid Phosphatase; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D015415:Biomarkers; D056657:Cathepsin K; D007527:Isoenzymes; D008070:Lipopolysaccharides; D010457:Peptidoglycan; D000071681:Tartrate-Resistant Acid Phosphatase; D013682:Teichoic Acids; C067980:CD68 antigen, human; D000097382:CD68 Molecule; C009900:lipoteichoic acid; C534130:CTSK protein, human