title: Detection of paroxysmal nocturnal hemoglobinuria-phenotype in patients with chronic lymphocytic leukemia and multiple myeloma.
abstract: BACKGROUND
  Paroxysmal nocturnal hemoglobinuria (PNH) results due to decrease or absence of glycosylphosphatidylinositol-anchored (GPI) molecules, such as CD55 and CD59, from the surface of the affected cells. PNH-phenotype has been described in various hematological disorders, mainly aplastic anemia and myelodysplastic syndromes; recently it has been reported in patients with lymphoproliferative syndromes and multiple myeloma (MM).
  
  
  METHODS
  We evaluated the presence of CD55 negative and/or CD59 negative red blood cell (RBC) populations in newly diagnosed treatment naive-54 chronic lymphocytic leukemia (CLL) and 29 MM patients by flow cytometry.
  
  
  RESULTS
  PNH-phenotype was not reported in any patient; however, RBC populations deficient in CD55 were detected in 16.66% (9/54) CLL and 6.89% (2/29) MM patients. Clinical presentation or the hematological parameters did not show any relationship with the presence of CD55 deficient RBC population.
  
  
  CONCLUSIONS
  Our study showed absence of PNH-phenotype in patients with CLL and MM; however, isolated CD55 deficient RBC were identified in both CLL and MM. Larger prospective studies by other centers, including simultaneous analysis of granulocytes for the presence of PNH-phenotype, are needed to corroborate these findings and to work out the mechanisms and the significance of the existence of this phenotype in these patients.
authors: Department of Internal Medicine and Hematology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
authors: S
authors: S
authors: Varma
authors: N
authors: N
authors: Varma
authors: V V
authors: VV
authors: Reddy
authors: S
authors: S
authors: Naseem
authors: P
authors: P
authors: Bose
authors: P
authors: P
authors: Malhotra
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018958:CD55 Antigens / Q000032:analysis; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D006457:Hemoglobinuria, Paroxysmal / Q000175:diagnosis*; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000150:complications*; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000150:complications*
chemical_list: D018958:CD55 Antigens