Evaluation of envelope domain III-based single chimeric tetravalent antigen and monovalent antigen mixtures for the detection of anti-dengue antibodies in human sera

A sera panel (n = 164) was assembled and characterized using commercial kits for infection by DENV and a host of other pathogens. Anti-DENV antibodies of both IgM and IgG classes in this panel were detected in indirect ELISAs using a mixture of monovalent EDIIIs, a chimeric EDIII-based tetravalent antigen, EDIII-T, and a biotinylated version of the latter as coating antigens. The sensitivity and specificity of these assays were compared to those obtained using the PanBio Dengue IgG/IgM ELISAs.The performance of dengue IgG and IgM indirect ELISAs, using either a physical mixture of four EDIIIs or the single chimeric EDIII-T antigen, were comparable. Coating of a biotinylated version of the tetravalent antigen on streptavidin plates enhanced sensitivity without compromising specificity.The incorporation of the EDIIIs of the four DENV serotypes into a single chimeric antigen did not adversely affect assay outcome in indirect ELISAs. Oriented, rather than random, immobilization of the tetravalent antigen enhanced sensitivity of detection of anti-DENV antibodies with retention of 100% specificity.Dengue viruses (DENV), of which there are four serotypes (DENV-1,-2,-3 and -4), are mosquito-borne flaviviruses of the Flaviviridae family, which also includes other members, such as yellow fever virus, Japanese encephalitis virus, West Nile virus and tick-borne encephalitis virus (TBEV) [1]. Currently, there is no vaccine to prevent or a drug to treat DENV infection, which poses a public health threat to nearly half the global population [2]. In this scenario, the availability of reliable diagnostic tools assumes great importance in clinical management, surveillance and outbreak investigations. As DENVs share antigenic similarities with other flaviviruses and tend to co-circulate with some of them in many endemic areas, the unambiguous detection of anti-DENV antibodies using currently available commercial kits, which use mixtures of inactivated virus preparations or recombinant