Development of peptide-based chemiluminescence enzyme immunoassay (CLEIA) for diagnosis of dengue virus infection in human.

Dengue is the most prevalent mosquito-borne viral disease in tropical and subtropical regions worldwide. Since its clinical symptoms are non-specific and easily mistaken as other kinds of infection, laboratory diagnosis is required to confirm dengue infections. In this study, ten peptides (E1-E10) from the envelope protein of dengue virus (DENV) were first identified using bioinformatic tool. The screened peptides were then synthesized for the peptide-based chemiluminescence enzyme immunoassay (CLEIA). Two peptides, E1 and E7, were found as the best candidate antigen and therefore used as downstream application in the development of low-cost peptide-based anti-DENV immunoglobulin M antibodies (IgM) indirect CLEIA. 176 serum samples were used to study the presence of anti-DENV IgM antibodies to evaluate the diagnostic ability of IgM-CLEIA. Receiver operating characteristic curve (ROC) was used to estimate the diagnostic cut-off value. The sensitivity and the specificity reached 82.5% and 94.6% respectively when peptide E1 was used, but declined to 79.2% and 92.9% respectively when peptide E7 was used. Therefore, the combination of E1 and E7 was used to improve the sensitivity and the specificity to 85.0% and 96.4% respectively in 1.5 h assay time, providing a potentially practical use for the diagnosis of DENV infections in patients' serum.