title: Diagnostic and prognostic potential of extracellular vesicles in peripheral blood.
abstract: OBJECTIVE
  Extracellular vesicles (EVs) are small, membrane-enclosed entities released from cells in many different biological systems. These vesicles play an important role in cellular communication by virtue of their protein, RNA, and lipid content, which can be transferred among cells. The complement of biomolecules reflects the parent cell, and their characterization may provide information about the presence of an aberrant process. Peripheral blood is a rich source of circulating EVs, which are easily accessible through a blood sample. An analysis of EVs in peripheral blood could provide access to unparalleled amounts of biomarkers of great diagnostic and prognostic value. The objectives of this review are to briefly present the current knowledge about EVs and to introduce a toolbox of selected techniques, which can be used to rapidly characterize clinically relevant properties of EVs from peripheral blood.
  
  
  METHODS
  Several techniques exist to characterize the different features of EVs, including size, enumeration, RNA cargo, and protein phenotype. Each technique has a number of advantages and pitfalls. However, with the techniques presented in this review, a possible platform for EV characterization in a clinical setting is outlined.
  
  
  RESULTS
  Although EVs have great diagnostic and prognostic potential, a lack of standardization regarding EV analysis hampers the full use of this potential. Nevertheless, the analysis of EVs in peripheral blood has several advantages compared with traditional analyses of many soluble molecules in blood.
  
  
  CONCLUSIONS
  Overall, the use of EV analysis as a diagnostic and prognostic tool has prodigious clinical potential.
authors: Laboratory for Medical Mass Spectrometry, Section for Biomedicine, Aalborg University, Aalborg, Denmark.
authors: Anne Louise Schacht
authors: AL
authors: Revenfeld
authors: Department of Clinical Immunology, Aalborg University Hospital, Aalborg, Denmark.
authors: Rikke
authors: R
authors: Bæk
authors: Department of Clinical Biochemistry, Aalborg University Hospital, Aalborg, Denmark.
authors: Morten Hjuler
authors: MH
authors: Nielsen
authors: Laboratory for Medical Mass Spectrometry, Section for Biomedicine, Aalborg University, Aalborg, Denmark.
authors: Allan
authors: A
authors: Stensballe
authors: Department of Clinical Immunology, Aalborg University Hospital, Aalborg, Denmark.
authors: Kim
authors: K
authors: Varming
authors: Department of Clinical Immunology, Aalborg University Hospital, Aalborg, Denmark. Electronic address: maljoe@rn.dk.
authors: Malene
authors: M
authors: Jørgensen
mesh_terms: D017209:Apoptosis / Q000502:physiology; D015415:Biomarkers / Q000097:blood; D055354:Exosomes / Q000737:chemistry; D000067128:Extracellular Vesicles / Q000737:chemistry / Q000473:pathology; D006801:Humans; D016130:Immunophenotyping; D009682:Magnetic Resonance Spectroscopy; D035683:MicroRNAs; D009369:Neoplasms / Q000378:metabolism / Q000473:pathology; D010641:Phenotype; D011379:Prognosis; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D015415:Biomarkers; D035683:MicroRNAs
keywords: Extracellular vesicles; RNA cargo; diagnostics; enumeration; exosomes; microvesicles; phenotyping