title: The dysfunction of platelets in paroxysmal nocturnal hemoglobinuria.
abstract: BACKGROUND
  Thrombosis is a dangerous complication of paroxysmal nocturnal hemoglobinuria (PNH) and has a high mortality rate. However, the mechanism underlying the development of thrombosis in PNH remains unclear. To explore this, platelet function and serum complement activity were investigated in 14 patients with classical PNH, 11 with PNH aplastic anemia (AA) and 30 healthy controls.
  
  
  METHODS
  Serum concentrations of the terminal complement complex (sC5b-9) were determined by enzyme-linked immunofluorescence assay (ELISA), and the levels of C5b-9, CD61 and CD62p on platelet membranes were determined by flow cytometry. Clinical parameters were assessed, including D-dimer and platelet aggregation induced by adenosine diphosphate (ADP) and arachidonic acid (ARA).
  
  
  RESULTS
  Serum sC5b-9 concentrations were significantly lower in the PNH/PNH-AA than in the control group (P<0.01). C5b-9 deposition was significantly higher on CD59-platelets than on CD59+platelets in PNH/PNH-AA patients and healthy controls (P<0.01 for each). D-dimer concentration was significantly higher in PNH/PNH-AA patients - especially those with lactate dehydrogenase (LDH) concentrations>1000U/L - than in controls (P<0.05). CD61 (P<0.05) expression was lower on CD59+platelets in PNH than in controls and CD5-platelets in PNH. Expression of CD62p (P<0.01) was lower on CD59-and CD59+platelets (P<0.01) in PNH cases than in controls. Platelet aggregation stimulated by the agonists ADP and ARA in the PNH/PNH-AA patients was significantly lower than that in controls (P<0.05).
  
  
  CONCLUSIONS
  The adhesion and aggregation of platelets, especially of CD59+platelets, were compensatively decreased in PNH/PNH-AA patients without active thrombosis.
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China. Electronic address: florai@sina.com.
authors: Rong
authors: R
authors: Fu
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China.
authors: Yinping
authors: Y
authors: Meng
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China.
authors: Yihao
authors: Y
authors: Wang
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China.
authors: Hui
authors: H
authors: Liu
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China.
authors: Yi
authors: Y
authors: Liu
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China.
authors: Lijuan
authors: L
authors: Li
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China.
authors: Shaoxue
authors: S
authors: Ding
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China.
authors: Guojin
authors: G
authors: Wang
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China.
authors: Jia
authors: J
authors: Song
authors: Department of Hematology, Tianjin Medical University General Hospital, Tianjin, PR China. Electronic address: shaozonghong@sina.com.
authors: Zonghong
authors: Z
authors: Shao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000741:Anemia, Aplastic / Q000097:blood / Q000150:complications* / Q000276:immunology / Q000473:pathology*; D001792:Blood Platelets / Q000276:immunology / Q000473:pathology*; D002648:Child; D003167:Complement Activation; D015938:Complement Membrane Attack Complex / Q000032:analysis; D005260:Female; D005338:Fibrin Fibrinogen Degradation Products / Q000032:analysis / Q000276:immunology; D006457:Hemoglobinuria, Paroxysmal / Q000097:blood / Q000150:complications* / Q000276:immunology / Q000473:pathology*; D006461:Hemolysis; D006801:Humans; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation; D013927:Thrombosis / Q000097:blood / Q000209:etiology* / Q000276:immunology / Q000473:pathology; D055815:Young Adult
chemical_list: D015938:Complement Membrane Attack Complex; D005338:Fibrin Fibrinogen Degradation Products; C047610:SC5b-9 protein complex; C036309:fibrin fragment D
keywords: Complement; D-dimer; Hemoglobinuria, paroxysmal; Platelet; Thrombosis