title: The peripheral blood of Aβ binding RBC as a biomarker for diagnosis of Alzheimer's disease.
abstract: BACKGROUND
  in vitro, it has been reported that amyloid β (Aβ) is bound to red blood cells (RBCs) and this process damages the red cell. Also, a possible relationship between RBCs and Alzheimer's disease (AD) is supported by the findings of RBC impairment in AD. Therefore, Aβ fibrils bounding RBC are of great interest as potential biomarkers.
  
  
  METHODS
  in this study, we focused on Aβ amyloid fibrils and/or aggregation on the peripheral RBC from 50 subjects with AD and 50 healthy controls (HCs) through thioflavin T (ThT) staining followed by immunofluorescence assay to confirm the presence of Aβ amyloid fibrils and/or aggregation on the RBC. Then we optimised fluorescence staining and imaging conditions and analysed the images obtained by image processing software.
  
  
  RESULTS
  we have analysed RBC morphology in blood from 50 subjects with AD and 50 HCs found that 16.8% of the RBCs are elongated as compared with 6.7% in normal controls (P < 0.01), and there is a negative correlation between the two parameters (P < 0.05). Our study showed that 98% of AD peripheral RBCs were amyloid binding-positive (ranging from 2 to 30%), while only 38% that of RBCs (ranging from 2 to 3.4%) were in HCs. We also found four modified morphologies of RBCs triggered by Aβ binding, which may serve as an ancillary investigation and indicate the progression of AD.
  
  
  CONCLUSIONS
  we first directly prove the existence of Aβ binding RBCs in peripheral blood. In addition, we observed new modified morphologies of RBC triggered by Aβ binding, all of those can serve as a biomarker for the diagnosis and progression of AD.
authors: School of Medical Laboratory, Tianjin Medical University, Tianjin, Tianjin 300203, China.
authors: Jie
authors: J
authors: Lan
authors: Department of Neurology, Tianjin Medical University Hospital, Tianjin, Tianjin, China.
authors: Jinping
authors: J
authors: Liu
authors: The Technical Center for Safety of Industrial Products of Tianjin Entry-Exit Inspection and Quarantine Bureau, Tianjin, Tianjin, China.
authors: Zhuo
authors: Z
authors: Zhao
authors: Department of Neurology, Tianjin Medical University Hospital, Tianjin, Tianjin, China.
authors: Rong
authors: R
authors: Xue
authors: Department of Neurology, Tianjin Medical University Hospital, Tianjin, Tianjin, China.
authors: Nan
authors: N
authors: Zhang
authors: Department of Neurology, Tianjin Huanhu Hospital, Tianjin, Tianjin, China.
authors: Peilan
authors: P
authors: Zhang
authors: Department of Neurology, Tianjin Medical University Hospital, Tianjin, Tianjin, China.
authors: Peng
authors: P
authors: Zhao
authors: School of Medical Laboratory, Tianjin Medical University, Tianjin, Tianjin 300203, China.
authors: Fang
authors: F
authors: Zheng
authors: School of Medical Laboratory, Tianjin Medical University, Tianjin, Tianjin 300203, China.
authors: Xuguo
authors: X
authors: Sun
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000097:blood / Q000175:diagnosis*; D016229:Amyloid beta-Peptides / Q000097:blood* / Q000378:metabolism; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004912:Erythrocytes / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D009483:Neuropsychological Tests
chemical_list: D016229:Amyloid beta-Peptides; D015415:Biomarkers
keywords: Alzheimer's disease; Aβ fibrils; older people; red blood cells; thioflavin T