High frequency of pre-existing neutralizing antibody responses in patients with dengue during an outbreak in Central Brazil

• Published in: BMC infectious diseases 2016-10, Vol.16 (1), p.546-546, Article 546
• Main Authors: de Teive E Argolo, Angela Ferreira Lopes, de Rezende Féres, Valéria Christina, Cordeiro, Marli Tenório, da Silveira, Lucimeire Antonelli, Guilarde, Adriana Oliveira, de Azevedo Marques, Jr, Ernesto Torres, de Souza, Wayner Vieira, Martelli, Celina Maria Turchi
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Antibodies, Neutralizing - blood; Antibodies, Neutralizing - immunology; Antibodies, Viral - blood; Antibodies, Viral - genetics; Antibodies, Viral - immunology; Brazil - epidemiology; Care and treatment; Causes of; Child; Child, Preschool; Cohort Studies; Dengue; Dengue - epidemiology; Dengue - immunology; Dengue Virus - classification; Dengue Virus - immunology; Dengue Virus - pathogenicity; Disease Outbreaks; Female; Humans; Immunoglobulin G; Influence; Male; Middle Aged; Neutralization Tests; Serogroup; Severe Dengue - epidemiology; Severe Dengue - immunology; Young Adult
• ISSN: 1471-2334; 1471-2334
• DOI: 10.1186/s12879-016-1867-6

This study aims to identify dengue neutralizing antibody response in patients with dengue from a well-characterized cohort during an outbreak in central Brazil, 2012-2013. We analyzed paired samples from 40 patients with severe dengue and 20 patients with dengue. Eligibility criteria were: IgM, NS1Ag and/or RT-PCR positivity and positive IgG result. Plaque reduction neutralization test (PRNT ) from DENV-1 to DENV-4 was performed to identify serotype-specific NAbs response. An infecting serotype was defined as ≥4-fold increase in DENV NAbs in paired samples. Monotypic response was classified as PRNT  ≥ 1/20 to only one DENV serotype, and multitypic response was considered to be PRNT  ≥ 1/20 to two or more serotypes simultaneously. Patients were mainly adults. Virological dengue infection was confirmed by RT-PCR: DENV-4(n = 14) and DENV-1(n = 10). Forty-four out of 60(73.3 %) patients had NAbs to DENV-4, DENV-1(68.3 %), DENV-2(68.3 %) and DENV-3(61.6 %) respectively. Fifteen percent of the cases presented monotypic response, whereas 85 % had multitypic response. DENV-4 infected-patients presented the greatest difference in PRNT titers compared with other serotypes. Pre-existing DENV NAbs was not correlated with disease severity. This was the first time that DENV-4 was implicated in an epidemic in the region. Our data indicates high exposure of multiple DENV serotypes in all age groups in the pre-dengue vaccine era and also previous to Zika virus introduction in Brazil.