title: Associations of ABO, D, and Lewis blood groups and HLA Class I and Class II alleles with West Nile virus Lineage 2 disease outcome in Greece, 2010 to 2013.
abstract: West Nile virus (WNV) infection, commonly asymptomatic, may cause mild West Nile fever (WNF) or potentially fatal neuroinvasive disease (WNND). An outbreak of 262 cases of the new Lineage 2 strain in Greece in 2010 continued with high mortality (17%) in WNND. The objective was to investigate ABO, D, and Lewis blood groups, as well as HLA Class I and Class II alleles, in relation to WNV Lineage 2 disease morbidity.
  
  
  
  A cohort of 132 Greek WNV cases in 2010 to 2013 (65% male; mean age 64 years; 41% WNF, 59% WNND) was compared to 51,339 healthy WNV-negative blood donors and 246 healthy subjects.
  
  
  
  Blood group A was more common in WNV cases (51%) than blood donors (39%) and group O less common (32% vs. 42%). D negativity within group A was higher in WNV than in blood donors (18% vs. 10%, p = 0.044). The frequency of secretors (Lewis(a-b+)) was 60% in WNV and 68% in donors (p = 0.16). HLA alleles C*08, DRB1*O4:O5, and DQB1*O2 occurred significantly less frequently in WNV than controls (p < 0.05 unadjusted for multiple testing) and DRB1*10:O1 more frequently (p = 0.039).
  
  
  
  This first study of symptomatic WNV Lineage 2 suggests A/D negativity as a new risk factor associated with WNV infection and level of morbidity. Further studies are required of the possibility that HLA C*08, DRB1*O4:O5, and DQB1*O2 are protective alleles and DRB1*10:O1 a "susceptible" allele to WNV infection and the role of secretor status in relation to WNV infection.
authors.affiliation: Coordinating Haemovigilance Centre.|Hellenic Centre for Disease Control and Prevention, Athens, Greece.
authors.forename: Constantina
authors.initials: C
authors.lastname: Politis
authors.affiliation: Coordinating Haemovigilance Centre.|Hellenic Centre for Disease Control and Prevention, Athens, Greece.
authors.forename: Myrsini
authors.initials: M
authors.lastname: Parara
authors.affiliation: Hellenic Centre for Disease Control and Prevention, Athens, Greece.
authors.forename: Jenny
authors.initials: J
authors.lastname: Kremastinou
authors.affiliation: AHEPA University Hospital Blood Centre Thessaloniki, Thessaloniki, Greece.
authors.forename: Eleni
authors.initials: E
authors.lastname: Hasapopoulou
authors.affiliation: National Histocompatibility Centre.
authors.forename: Aliki
authors.initials: A
authors.lastname: Iniotaki
authors.affiliation: National Histocompatibility Centre.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Siorenta
authors.affiliation: Coordinating Haemovigilance Centre.|Panteion University of Social and Political Sciences, Athens, Greece.
authors.forename: Clive
authors.initials: C
authors.lastname: Richardson
authors.affiliation: Arboviruses National Reference Laboratory, Aristoteleio University, Thessaloniki, Greece.
authors.forename: Anna
authors.initials: A
authors.lastname: Papa
authors.affiliation: Coordinating Haemovigilance Centre.|Hellenic Centre for Disease Control and Prevention, Athens, Greece.
authors.forename: Lilian
authors.initials: L
authors.lastname: Kavallierou
authors.affiliation: Coordinating Haemovigilance Centre.|Hellenic Centre for Disease Control and Prevention, Athens, Greece.
authors.forename: Marina
authors.initials: M
authors.lastname: Asariotou
authors.affiliation: Laiko General Hospital Blood Establishment, Athens, Greece.
authors.forename: Olga
authors.initials: O
authors.lastname: Katsarou
authors.affiliation: Rio University Hospital Blood Centre, Patras, Greece.
authors.forename: Athina
authors.initials: A
authors.lastname: Mougiou
authors.affiliation: Tzanio General Hospital Blood Establishment, Piraeus, Greece.
authors.forename: Lukas
authors.initials: L
authors.lastname: Dadiotis
authors.affiliation: Asclepieio General Hospital Blood Establishment, Voula, Greece.
authors.forename: Zafeiria
authors.initials: Z
authors.lastname: Alexandropoulou
authors.affiliation: Evangelismos General Hospital Blood Establishment, Athens, Greece.
authors.forename: Angelica
authors.initials: A
authors.lastname: Megalou
authors.affiliation: Veria General Hospital Blood Establishment, Imathia, Greece.
authors.forename: Evangelia
authors.initials: E
authors.lastname: Magoula
authors.affiliation: Katerini General Hospital Blood Establishment, Pieria, Greece.
authors.forename: Margarita
authors.initials: M
authors.lastname: Papadopoulou
authors.affiliation: Hellenic Centre for Disease Control and Prevention, Athens, Greece.
authors.forename: Danai
authors.initials: D
authors.lastname: Pervanidou
authors.affiliation: Hellenic Centre for Disease Control and Prevention, Athens, Greece.
authors.forename: Agoritsa
authors.initials: A
authors.lastname: Baka
authors.affiliation: Department of Hygiene and Epidemiology, University of Thessaly, Larissa, Greece.
authors.forename: Christos
authors.initials: C
authors.lastname: Hadjichristodoulou
mesh_terms: D000017:ABO Blood-Group System / Q000235:genetics*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000483:Alleles; D001782:Blood Donors / Q000706:statistics & numerical data; D004196:Disease Outbreaks; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D006115:Greece; D006680:HLA Antigens / Q000235:genetics; D006801:Humans; D007983:Lewis Blood Group Antigens / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D014901:West Nile Fever / Q000235:genetics / Q000635:transmission*; D014902:West Nile virus / Q000472:pathogenicity*; D055815:Young Adult
chemical_list: D000017:ABO Blood-Group System; D006680:HLA Antigens; D007983:Lewis Blood Group Antigens