title: Paroxysmal nocturnal hemoglobinuria testing by flow cytometry. Evaluation of the REDQUANT and CELLQUANT kits.
abstract: The commercially available REDQUANT and CELLQUANT kits were evaluated in a clinical flow cytometry laboratory using healthy volunteers and a small series of 5 patients with paroxysmal nocturnal hemoglobinuria (PNH). Most samples also were tested with a "home brew" antibody panel for CD66b expression on granulocytes and CD14 expression on monocytes. The REDQUANT and CELLQUANT kits in tandem correctly identified all 5 PNH samples with no false-positive results. The 1 PNH sample from a patient with a negative Ham test result also was identified correctly. One marker, CD59 on granulocytes, when considered alone, had a high false-positive rate, and I suggest lowering the fluorescence intensity criteria for identifying decreased antigen expression. The home-brew tube also performed well, identifying all 5 patients, and may serve as a supplement in difficult specimens. The evaluated kits performed well. However, the validation series was small, which is likely to be a problem at any single institution. The provision of a reproducible manufacturer-defined expression level for normal cells adds another degree of confidence that the test correctly identifies patients with this potentially life-threatening disorder while avoiding false-positive results.
authors.affiliation: Department of Clinical Pathology, Cleveland Clinic Foundation, OH 44195, USA.
authors.forename: E D
authors.initials: ED
authors.lastname: Hsi
mesh_terms: D000328:Adult; D000368:Aged; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D018958:CD55 Antigens / Q000032:analysis; D018957:CD59 Antigens / Q000032:analysis; D015815:Cell Adhesion Molecules; D004912:Erythrocytes / Q000276:immunology; D005069:Evaluation Studies as Topic; D005260:Female; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D058851:GPI-Linked Proteins; D006098:Granulocytes / Q000276:immunology; D006457:Hemoglobinuria, Paroxysmal / Q000097:blood*; D006801:Humans; D016130:Immunophenotyping; D018950:Lipopolysaccharide Receptors / Q000032:analysis; D008297:Male; D008562:Membrane Glycoproteins / Q000032:analysis; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology; D011933:Reagent Kits, Diagnostic
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; D018958:CD55 Antigens; D018957:CD59 Antigens; C504120:CEACAM8 protein, human; D015815:Cell Adhesion Molecules; D005456:Fluorescent Dyes; D058851:GPI-Linked Proteins; D018950:Lipopolysaccharide Receptors; D008562:Membrane Glycoproteins; D011933:Reagent Kits, Diagnostic; D016650:Fluorescein-5-isothiocyanate