title: A novel marker for screening paroxysmal nocturnal hemoglobinuria using routine complete blood count and cell population data.
abstract: BACKGROUND
  Final diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) may take years demanding a quick diagnosis measure. We used the facts that PNH cells are damaged in acid, and reagents for measuring reticulocytes in Coulter DxH800 (Beckman Coulter, USA) are weakly acidic and hypotonic, to create a new PNH screening marker.
  
  
  METHODS
  We analyzed 979 complete blood counts (CBC) data from 963 patients including 57 data from 44 PNH patients. Standard criteria for PNH assay for population selection were followed: flow cytometry for CD55 and CD59 on red blood cells (RBCs) to a detection level of 1%; and fluorescent aerolysin, CD24 and CD15 in granulocytes to 0.1%. Twenty-four PNH minor clone-positive samples (minor-PNH+) were taken, in which the clone population was <5% of RBCs and/or granulocytes. Excluding PNH and minor-PNH+ patients, the population was divided into anemia, malignancy, infection, and normal groups. Parameters exhibiting a distinct demarcation between PNH and non-PNH groups were identified, and each parameter cutoff value was sought that includes the maximum [minimum] number of PNH [non-PNH] patients.
  
  
  RESULTS
  Cutoff values for 5 selected CBC parameters (MRV, RDWR, MSCV, MN-AL2-NRET, and IRF) were determined. Positive rates were: PNH (86.0%), minor-PNH+ (33.3%), others (5.0%), anemia (13.4%), malignancy (5.3%), infection (3.7%), normal (0.0%); within anemia group, aplastic anemia (40.0%), immune hemolytic anemia (11.1%), iron deficiency anemia (1.6%). Sensitivity (86.0%), specificity (95.0%), PPV (52.1%), and NPV (99.1%) were achieved in PNH screening.
  
  
  CONCLUSIONS
  A new PNH screening marker is proposed with 95% specificity and 86% sensitivity. The flag identifies PNH patients, reducing time to final diagnosis by flow cytometry.
authors.affiliation: Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jimin
authors.initials: J
authors.lastname: Kahng
authors.affiliation: Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Yonggoo
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jung Ok
authors.initials: JO
authors.lastname: Kim
authors.affiliation: Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Kwangsang
authors.initials: K
authors.lastname: Koh
authors.affiliation: Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Jong Wook
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Kyungja
authors.initials: K
authors.lastname: Han
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001772:Blood Cell Count; D051927:CD24 Antigen / Q000378:metabolism; D018958:CD55 Antigens / Q000378:metabolism; D018957:CD59 Antigens / Q000378:metabolism; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism; D005434:Flow Cytometry; D006098:Granulocytes / Q000166:cytology / Q000378:metabolism; D006457:Hemoglobinuria, Paroxysmal / Q000175:diagnosis* / Q000378:metabolism; D006801:Humans; D016256:Lewis X Antigen / Q000378:metabolism; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D051927:CD24 Antigen; D018958:CD55 Antigens; D018957:CD59 Antigens; D016256:Lewis X Antigen
keywords: Complete blood count; Paroxysmal nocturnal hemoglobinuria; Reticulocyte-related parameters; Screening marker