title: Identification of circulating melanoma cells in uveal melanoma patients by dual-marker immunoenrichment.
abstract: OBJECTIVE
  Despite successful local tumor control, uveal melanoma (UM) patients may develop lethal metastases. To reliably identify circulating melanoma cells (CMC) in UM patients, we set out to test a new immunomagnetic enrichment assay and screened UM patients for the presence of CMC. We also determined whether we could find CMC in culture; for example, for future drug testing.
  
  
  METHODS
  A dual-immunomagnetic enrichment assay using antibodies against two melanoma markers (NKI/C3 and NKI/beteb) was used to determine the presence of UM cells in blood. The sensitivity of the assay was determined by spiking normal blood with 92.1 cells (concentration range, 1-10(4) cells/mL). Isolated cells were characterized by immunocytochemistry directly after immunoenrichment and after a 2-week culture. The presence of CMC was determined in the peripheral blood of 31 patients with UM, and results were compared to clinical prognostic factors at the time of presentation.
  
  
  RESULTS
  The CMC were detected in 93.5% (n = 29 of 31) of the patients with primary nonmetastatic UM at a median density of 3.5 cells/10 mL blood (range, 0-10.2 cells), as well as in blood cultures. No significant association was observed between the presence or number of CMC and any clinical prognostic factors.
  
  
  CONCLUSIONS
  The improved dual-immunoenrichment assay enabled the detection of intact and viable CMC in the majority of UM patients. We also were able to identify CMC after short-term culturing. Molecular characterization of the CMC rather than the prevalence of these cells is expected to provide relevant information on the individual risk of metastasis.
authors: Department of Ophthalmology, University of Lübeck, Lübeck, Germany.
authors: Aysegül
authors: A
authors: Tura
authors: Department of Ophthalmology, University of Lübeck, Lübeck, Germany.
authors: Julia
authors: J
authors: Lüke
authors: Department of Pathology, University of Lübeck, Lübeck, Germany.
authors: Hartmut
authors: H
authors: Merz
authors: Department of Ophthalmology, University of Lübeck, Lübeck, Germany.
authors: Mihaela
authors: M
authors: Reinsberg
authors: Department of Ophthalmology, University of Lübeck, Lübeck, Germany.
authors: Matthias
authors: M
authors: Lüke
authors: Department of Ophthalmology, J3-S, Leiden University Medical Center, Leiden, The Netherlands.
authors: Martine J
authors: MJ
authors: Jager
authors: Department of Ophthalmology, University of Lübeck, Lübeck, Germany.
authors: Salvatore
authors: S
authors: Grisanti
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D018189:Immunomagnetic Separation / Q000379:methods*; D008297:Male; D008545:Melanoma / Q000175:diagnosis / Q000556:secondary*; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating / Q000276:immunology / Q000473:pathology*; D012189:Retrospective Studies; D014407:Tumor Cells, Cultured; D014604:Uveal Neoplasms / Q000175:diagnosis / Q000556:secondary*; D000098943:Uveal Melanoma
chemical_list: D014408:Biomarkers, Tumor
keywords: circulating melanoma cells; immunoenrichment; uveal melanoma