title: CD14+ CD16+ monocytes rather than CD14+ CD51/61+ monocytes are a potential cytological marker of circulating osteoclast precursors in multiple myeloma. A preliminary study.
abstract: BACKGROUND
  Osteolytic bone destruction is a major clinical problem in multiple myeloma patients. Osteoclasts can differentiate in vitro from bone marrow-resident monocyte progenitors, such as common monocyte progenitors, as well as circulating monocytes. Various types of monocytes, including osteoclast precursors, appear to circulate systemically.
  
  
  METHODS
  We investigated the possibility of demonstrating, by in vitro differentiation and flow cytometry, a circulating osteoclast precursor population in multiple myeloma (MM) patients by studying the distribution of CD14(+/++) CD11b(+) CD51/61(+) and CD14(+/++) CD16(+/-) populations.
  
  
  RESULTS
  Under short-term in vitro osteoclastic differentiation conditions, almost all CD14 monocytes acquired CD51/61 and CD16 expression. Flow cytometry studies failed to demonstrate a statistically significant increase in circulating CD14(+/++) CD11b(+) CD51/61(+) populations in 20 MM patients with osteolytic lesions. However, the minor circulating CD14(+/++) CD16(+) fraction was significantly increased in MM patients compared with healthy volunteers (109.3 ± 63.1/mm(3) vs. 65.3 ± 34.9/mm(3) ; P = 0.005), but with no correlation with markers of tumour burden. The CD14(+/++) CD16(+) to CD14(+/++) CD16(-) ratio was higher in MM patients.
  
  
  CONCLUSIONS
  The circulating CD14(+/++) CD11b(+) CD51/61(+) fraction was not correlated with bone lesions in MM patients. However, CD14(+/++) CD16(+) monocytes may be a candidate marker. A larger study must be conducted to confirm these promising results for the diagnosis and follow-up of MM patients.
authors.affiliation: Haematology and Histocompatibility Laboratory, Amiens University Hospital, Amiens, France.
authors.forename: V
authors.initials: V
authors.lastname: Petitprez
authors.forename: B
authors.initials: B
authors.lastname: Royer
authors.forename: J
authors.initials: J
authors.lastname: Desoutter
authors.forename: E
authors.initials: E
authors.lastname: Guiheneuf
authors.forename: A
authors.initials: A
authors.lastname: Rigolle
authors.forename: J P
authors.initials: JP
authors.lastname: Marolleau
authors.forename: S
authors.initials: S
authors.lastname: Kamel
authors.forename: N
authors.initials: N
authors.lastname: Guillaume
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D002452:Cell Count; D002478:Cells, Cultured; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D039564:Integrin alphaV; D039661:Integrin beta3; D007963:Leukocytes, Mononuclear / Q000378:metabolism / Q000473:pathology; D018950:Lipopolysaccharide Receptors; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000378:metabolism* / Q000473:pathology; D009101:Multiple Myeloma / Q000175:diagnosis / Q000378:metabolism* / Q000473:pathology*; D010010:Osteoclasts / Q000378:metabolism* / Q000473:pathology; D010014:Osteolysis / Q000473:pathology; D017452:Receptors, IgG; D013997:Time Factors
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D039564:Integrin alphaV; D039661:Integrin beta3; D018950:Lipopolysaccharide Receptors; D017452:Receptors, IgG
keywords: Multiple myeloma; bone; monocytes; osteoclastic precursor