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R. Klaythong

Bio: R. Klaythong is an academic researcher from Mahidol University. The author has contributed to research in topics: Serotype & Restriction fragment length polymorphism. The author has an hindex of 2, co-authored 3 publications receiving 240 citations.

Papers
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Journal ArticleDOI
TL;DR: It is confirmed that classical HLA class I alleles are associated with the clinical outcome of exposure to dengue virus, in previously exposed and immunologically primed individuals.
Abstract: Little is known of the role of classical HLA-A and -B class I alleles in determining resistance, susceptibility, or the severity of acute viral infections. Appropriate paradigms for immunogenetic studies of acute viral infections are dengue fever (DF) and dengue hemorrhagic fever (DHF). Both primary and secondary infections with dengue virus (DEN) serotypes 1, 2, 3 or 4, can result in either clinically less severe DF or the more severe DHF. In secondary exposures, a memory response is induced in immunologically primed individuals, which can both clear the infecting dengue virus and contribute to its pathology. In a case-control study of 263 ethnic Thai patients infected with either DEN-1, -2, -3 or -4, we detected HLA class I associations with secondary infections, but not in immunologically naive patients with primary infections. HLA-A*0203 was associated with the less severe DF, regardless of the secondary infecting virus serotype. By contrast, HLA-A*0207 was associated with susceptibility to the more severe DHF in patients with secondary DEN-1 and DEN-2 infections only. Conversely, HLA-B*51 was associated with the development of DHF in patients with secondary infections, and HLA-B*52 was associated with DF in patients with secondary DEN-1 and DEN-2 infections. Moreover, HLA-B44, B62, B76 and B77 also appeared to be protective against developing clinical disease after secondary dengue virus infection. These results confirm that classical HLA class I alleles are associated with the clinical outcome of exposure to dengue virus, in previously exposed and immunologically primed individuals.

238 citations

Journal ArticleDOI
TL;DR: To validate and extend the above findings, genomic DNA was prepared from peripheral blood of all family members and digested with the restriction enzymes Eco RI, Taq I, Pvu II, and Hind III.
Abstract: Recently we had the opportunity to study a family from Bangkok in which unusual haplotypes, HLA-DRw15 (DR2) and DQw7 (DQw3), could be identified. The maternal haplotype is unusual in that it shows a combination of DRw15 and DQw7 (w3), which, to our knowledge, has thus far not been observed. To validate and extend the above findings, genomic DNA was prepared from peripheral blood of all family members and digested with the restriction enzymes Eco RI, Taq I, Pvu II, and Hind III

12 citations


Cited by
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Journal ArticleDOI
TL;DR: A global strategy aimed at increasing the capacity for surveillance and outbreak response, changing behaviours and reducing the disease burden using integrated vector management in conjunction with early and accurate diagnosis has been advocated.
Abstract: Dengue fever and dengue haemorrhagic fever are important arthropod-borne viral diseases. Each year, there are ∼50 million dengue infections and ∼500,000 individuals are hospitalized with dengue haemorrhagic fever, mainly in Southeast Asia, the Pacific and the Americas. Illness is produced by any of the four dengue virus serotypes. A global strategy aimed at increasing the capacity for surveillance and outbreak response, changing behaviours and reducing the disease burden using integrated vector management in conjunction with early and accurate diagnosis has been advocated. Antiviral drugs and vaccines that are currently under development could also make an important contribution to dengue control in the future.

1,732 citations

Journal ArticleDOI
TL;DR: This review explores the human, mosquito, and viral factors that contribute to the global spread and persistence of dengue, as well as the interaction between the three spheres, in the context of ecological and climate changes.
Abstract: Dengue is a spectrum of disease caused by four serotypes of the most prevalent arthropod-borne virus affecting humans today, and its incidence has increased dramatically in the past 50 years. Due in part to population growth and uncontrolled urbanization in tropical and subtropical countries, breeding sites for the mosquitoes that transmit dengue virus have proliferated, and successful vector control has proven problematic. Dengue viruses have evolved rapidly as they have spread worldwide, and genotypes associated with increased virulence have expanded from South and Southeast Asia into the Pacific and the Americas. This review explores the human, mosquito, and viral factors that contribute to the global spread and persistence of dengue, as well as the interaction between the three spheres, in the context of ecological and climate changes. What is known, as well as gaps in knowledge, is emphasized in light of future prospects for control and prevention of this pandemic disease.

831 citations

Journal ArticleDOI
TL;DR: A personalized approach to the study of pathogenesis will elucidate the basis of individual risk for development of DHF and DSS as well as identify the genetic and environmental bases for differences in risk forDevelopment of severe disease.
Abstract: Summary: Much remains to be learned about the pathogenesis of the different manifestations of dengue virus (DENV) infections in humans. They may range from subclinical infection to dengue fever, dengue hemorrhagic fever (DHF), and eventually dengue shock syndrome (DSS). As both cell tropism and tissue tropism of DENV are considered major determinants in the pathogenesis of dengue, there is a critical need for adequate tropism assays, animal models, and human autopsy data. More than 50 years of research on dengue has resulted in a host of literature, which strongly suggests that the pathogenesis of DHF and DSS involves viral virulence factors and detrimental host responses, collectively resulting in abnormal hemostasis and increased vascular permeability. Differential targeting of specific vascular beds is likely to trigger the localized vascular hyperpermeability underlying DSS. A personalized approach to the study of pathogenesis will elucidate the basis of individual risk for development of DHF and DSS as well as identify the genetic and environmental bases for differences in risk for development of severe disease.

816 citations

Journal ArticleDOI
TL;DR: An increased understanding of the adaptive immune response to natural d Dengue virus infection and candidate dengue vaccines has helped to define the specific antibody and T cell responses that are associated with either protective or pathological immunity during dengued infection.
Abstract: Dengue is a mosquito-borne viral disease of expanding geographical range and incidence. The existence of four viral serotypes and the association of prior dengue virus infection with an increased risk for more severe disease have presented significant obstacles to vaccine development. An increased understanding of the adaptive immune response to natural dengue virus infection and candidate dengue vaccines has helped to define the specific antibody and T cell responses that are associated with either protective or pathological immunity during dengue infection. Further characterization of immunological correlates of disease outcome and the validation of these findings in vaccine trials will be invaluable for developing effective dengue vaccines.

650 citations

Journal ArticleDOI
TL;DR: The unique immunological concerns in dengue virus vaccine development are discussed and the current prospects for the development of an acceptable vaccine are discussed, with a goal that is likely to be reached in the near future.
Abstract: The number of cases of severe dengue disease continues to grow in endemic areas of southeast Asia, Central and South America, and other subtropical regions. Children bear the greatest burden of disease, and the development of an effective vaccine remains a global public health priority. A tetravalent vaccine is urgently needed and must be effective against all four dengue virus serotypes, be cost-effective and provide long-term protection. In this Review we discuss the unique immunological concerns in dengue virus vaccine development and the current prospects for the development of an acceptable vaccine, a goal that is likely to be reached in the near future.

604 citations