1576. HLA Class I is strongly associated to dengue asymptomatic infections
Session: Poster Abstract Session: Microbial and Host Genetic Factors in Disease
Saturday, October 5, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • Poster IDWeek 2013.pdf (1.1 MB)
  • Background: Dengue is an acute febrile illness that affects annually about 100,000 people worldwide. It results from the infection by any of the four dengue viruses and its clinical manifestations range from asymptomatic infections or a mild disease (dengue fever) to a severe disease (dengue hemorrhagic fever/dengue shock syndrome [DHF/DSS]). Although several hypotheses try to explain DHF/DSS, little is known about the characteristics of asymptomatic patients. Determining these characteristics might help understanding the pathophysiology of this disease and shed some light on some potential markers of disease protection. A possible explanation for the asymptomatic infections is that the genetic background of some people prevents them from developing more severe clinical manifestations. Since the HLA system is intrinsically associated to some diseases, the aim of this work was to type and compare, among different groups of dengue patients, the expression of HLA class I (HLA-A, HLA-B and HLA-C) and class II (HLA-DQ and HLA-DQ).

    Methods: Enrolled subjects were divided into three groups: dengue fever patients (n= 109), asymptomatic patients (n= 17) and healthy individuals (n= 27). Asymptomatic patients were diagnosed either by the presence of NS1 protein, PCR or anti-dengue IgM antibody, and they were recruited from family members of dengue patients as long as they had not presented any dengue symptoms during the 3 months preceding the enrollment. Genomic DNA was extracted from peripheral blood of individuals using the QIAampR DNA Kit (QIAGENR) and HLA typing of dengue patients was done using LABType SSO typing kits (One Lambda, USA), both techniques performed according to the manufacturer's recommendations.

    Results: HLA-A*74, HLA-B*02, *03, *04, *05, *06, *12, *16, *17 and HLA-C*35, *39, *40, *42, *44, *45, *50, *51, *53, and *57 alleles contributed to a possible protective role against overt disease, while HLA-DR and –DQ showed no relevance regarding the protective role against disease.

    Conclusion: These results indicate that HLA Class I seem to have a key role in determining dengue asymptomatic infections. These HLA systems are associated to CD8+ cytotoxic T-cells, which leads us to assume that strong innate immunity and cellular immune response are crucial for determining the asymptomatic manifestations of dengue.

    Mariana Carolina Morais Sobral, BS, MSc1, Luiza Antunes Castro-Jorge, PhD1, Danillo Lucas Alves Esposito, BS, MS1, Luzia Márcia Romano Passos, RN, PhD2, Maria Luiza Santa Maria, RN, MSc3 and Benedito Antonio Lopes Da Fonseca, MD, PhD1, (1)Internal Medicine, University of São Paulo Medical School at Ribeirão Preto, Ribeirão Preto, Brazil, (2)Internal Medicine, Health Center of the University of São Paulo Medical School at Ribeirão Preto, Ribeirão Preto, Brazil, (3)Ribeirão Preto City Health Department, Ribeirão Preto, Brazil

    Disclosures:

    M. C. Morais Sobral, None

    L. A. Castro-Jorge, None

    D. L. Alves Esposito, None

    L. M. Romano Passos, None

    M. L. Santa Maria, None

    B. A. Lopes Da Fonseca, None

    << Previous Abstract | Next Abstract

    Findings in the abstracts are embargoed until 12:01 a.m. PST, Oct. 2nd with the exception of research findings presented at the IDWeek press conferences.