title: Antibody-dependent enhancement of dengue virus growth in human monocytes as a risk factor for dengue hemorrhagic fever.
abstract: Serum specimens collected during a prospective study of dengue infections among schoolchildren in Bangkok were tested for their ability to enhance dengue 2 (DEN-2) virus growth in human monocytes in vitro. Two groups of dengue-immune sera were compared: 32 dengue antibody positive serum specimens from children who subsequently developed asymptomatic secondary dengue infections; and 9 dengue antibody positive serum specimens from children who subsequently developed severe symptomatic secondary dengue infections, 8 of which were clinically diagnosed as dengue hemorrhagic fever. Antibody-dependent enhancement of virus growth was quantitated by measurement of virus yields in supernatant fluids of normal human monocyte cultures that were infected with DEN-2 virus in the presence of undiluted test serum. Only 4 of 32 (12%) preinfection sera from asymptomatic children, but 6 of 9 (67%) preinfection sera from symptomatic children, had significant enhancing activity (P less than 0.001). High serum DEN-2 antibody dependent enhancing activity is a significant (relative risk = 6.2) risk factor for severe illness among children in a dengue hemorrhagic fever endemic region. Dengue antibodies can be neutralizing and therefore protective, or they can be enhancing and increase the risk of dengue hemorrhagic fever.
authors.affiliation: Department of Virus Disease, Walter Reed Army Institute of Research, Washington, DC.
authors.forename: S C
authors.initials: SC
authors.lastname: Kliks
authors.forename: A
authors.initials: A
authors.lastname: Nisalak
authors.forename: W E
authors.initials: WE
authors.lastname: Brandt
authors.forename: L
authors.initials: L
authors.lastname: Wahl
authors.forename: D S
authors.initials: DS
authors.lastname: Burke
mesh_terms: D000914:Antibodies, Viral / Q000502:physiology*; D002478:Cells, Cultured; D002648:Child; D003715:Dengue / Q000209:etiology* / Q000382:microbiology; D003716:Dengue Virus / Q000254:growth & development*; D006801:Humans; D009000:Monocytes / Q000382:microbiology*; D009500:Neutralization Tests; D011446:Prospective Studies; D012307:Risk Factors; D013577:Syndrome; D010948:Viral Plaque Assay
chemical_list: D000914:Antibodies, Viral