title: Lack of evidence for a role of HHV-6 in the pathogenesis of Alzheimer's disease.
abstract: BACKGROUND
  Alzheimer's disease (AD), the most common form of dementia worldwide, is associated with impairment in the mechanisms of the clearing of amyloid-β within a scenario of neuroinflammation. The etiopathogenesis of the AD is unclear, but a role for viral infection is suspected to play a role in initiating the disease. We recently described a positive correlation between high titers of HSV-1-specific antibodies (Ab) and the volumes of brain regions typically affected in disease.
  
  
  OBJECTIVE
  The exploration of a possible role for Herpesviridae in AD was extended by analyzing HHV-6-specific humoral immunity in individuals with AD or a diagnosis of amnestic mild cognitive impairment (aMCI), a condition that is often prodromic of the development of AD.
  
  
  METHODS
  59 AD, 60 aMCI, and 61 age-matched healthy controls were enrolled in the study. Serum HHV-6 IgG antibody titers and avidity index were tested by ELISA. Two randomly selected subgroups of AD and aMCI in whom HHV-6 serum antibodies were detected underwent brain magnetic resonance imaging (MRI) by 1.5 T scanner.
  
  
  RESULTS
  HHV-6 seroprevalence, antibody titers, and avidity were similar in the three groups. No correlation was found between Ab titers or avidity and brain volumes, either overall or in the regions typically affected by disease.
  
  
  CONCLUSIONS
  The lack of any relation between humoral immune response against HHV-6 and AD and aMCI seems to rule out a role for this virus in the pathogenesis of AD.
authors.affiliation: Don C. Gnocchi Foundation - ONLUS, Milan, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Agostini
authors.affiliation: Don C. Gnocchi Foundation - ONLUS, Milan, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Mancuso
authors.affiliation: Don C. Gnocchi Foundation - ONLUS, Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Baglio
authors.affiliation: Don C. Gnocchi Foundation - ONLUS, Milan, Italy.
authors.forename: Monia
authors.initials: M
authors.lastname: Cabinio
authors.affiliation: Don C. Gnocchi Foundation - ONLUS, Milan, Italy.
authors.forename: Ambra
authors.initials: A
authors.lastname: Hernis
authors.affiliation: Don C. Gnocchi Foundation - ONLUS, Milan, Italy.
authors.forename: Franca Rosa
authors.initials: FR
authors.lastname: Guerini
authors.affiliation: Don C. Gnocchi Foundation - ONLUS, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Calabrese
authors.affiliation: Don C. Gnocchi Foundation - ONLUS, Milan, Italy.|Department of Physiopathology and Transplantation, University of Milan, Italy.
authors.forename: Raffaello
authors.initials: R
authors.lastname: Nemni
authors.affiliation: Don C. Gnocchi Foundation - ONLUS, Milan, Italy.|Department of Physiopathology and Transplantation, University of Milan, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Clerici
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000276:immunology* / Q000821:virology; D000906:Antibodies / Q000097:blood*; D016022:Case-Control Studies; D060825:Cognitive Dysfunction / Q000276:immunology* / Q000821:virology; D005260:Female; D018259:Herpesvirus 1, Human; D015654:Herpesvirus 6, Human; D006801:Humans; D056724:Immunity, Humoral; D008279:Magnetic Resonance Imaging; D008297:Male; D016036:Seroepidemiologic Studies; D013702:Temporal Lobe / Q000473:pathology*
chemical_list: D000906:Antibodies
keywords: Alzheimer’s disease; HHV-6; humoral immunity; magnetic resonance imaging