title: An inter-laboratory comparison of PNH clone detection by high-sensitivity flow cytometry in a Russian cohort.
abstract: OBJECTIVE
  Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal stem cell disorder characterized by partial or absolute deficiency of glycophosphatidyl-inositol (GPI) anchor-linked surface proteins on blood cells. A lack of precise diagnostic standards for flow cytometry has hampered useful comparisons of data between laboratories. We report data from the first study evaluating the reproducibility of high-sensitivity flow cytometry for PNH in Russia.
  
  
  METHODS
  PNH clone sizes were determined at diagnosis in PNH patients at a central laboratory and compared with follow-up measurements in six laboratories across the country. Analyses in each laboratory were performed according to recommendations from the International Clinical Cytometry Society (ICCS) and the more recent 'practical guidelines'. Follow-up measurements were compared with each other and with the values determined at diagnosis.
  
  
  RESULTS
  PNH clone size measurements were determined in seven diagnosed PNH patients (five females, two males: mean age 37 years); five had a history of aplastic anemia and three (one with and two without aplastic anemia) had severe hemolytic PNH and elevated plasma lactate dehydrogenase. PNH clone sizes at diagnosis were low in patients with less severe clinical symptoms (0.41-9.7% of granulocytes) and high in patients with severe symptoms (58-99%). There were only minimal differences in the follow-up clone size measurement for each patient between the six laboratories, particularly in those with high values at diagnosis.
  
  
  CONCLUSIONS
  The ICCS-recommended high-sensitivity flow cytometry protocol was effective for detecting major and minor PNH clones in Russian PNH patients, and showed high reproducibility between laboratories.
authors.forename: Alexandra A
authors.initials: AA
authors.lastname: Sipol
authors.forename: Elena V
authors.initials: EV
authors.lastname: Babenko
authors.forename: Vyacheslav I
authors.initials: VI
authors.lastname: Borisov
authors.forename: Elena V
authors.initials: EV
authors.lastname: Naumova
authors.forename: Elena V
authors.initials: EV
authors.lastname: Boyakova
authors.forename: Dimitry I
authors.initials: DI
authors.lastname: Yakunin
authors.forename: Tatyana V
authors.initials: TV
authors.lastname: Glazanova
authors.forename: Zhanna V
authors.initials: ZV
authors.lastname: Chubukina
authors.forename: Natalya V
authors.initials: NV
authors.lastname: Pronkina
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Popov
authors.forename: Leonid I
authors.initials: LI
authors.lastname: Saveliev
authors.forename: Svetlana A
authors.initials: SA
authors.lastname: Lugovskaya
authors.forename: Igor A
authors.initials: IA
authors.lastname: Lisukov
authors.forename: Alexander D
authors.initials: AD
authors.lastname: Kulagin
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Illingworth
mesh_terms: D000328:Adult; D000741:Anemia, Aplastic / Q000097:blood* / Q000473:pathology; D015331:Cohort Studies; D005260:Female; D005434:Flow Cytometry / Q000379:methods*; D006457:Hemoglobinuria, Paroxysmal / Q000097:blood* / Q000473:pathology; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012426:Russia
keywords: Flow cytometry; PIG-A, Phosphatidylinositol glycan A; PNH; Paroxysmal nocturnal hemoglobinuria