[Establishment and preliminary application of dengue virus envelope domain III IgG antibody capture enzyme-linked immuno-absorbent assay].

Objective To establish a highly sensitive and specific assay to detect dengue virus (DENV) envelope protein domain Ⅲ (ED Ⅲ) IgG antibody,and to explore its value in the diagnosis and seroepidemiological survey of dengue.Methods The DENV ED Ⅲ IgG antibody capture ELISA was developed using the recombinant full-length DENV ED Ⅲ,which was prepared by Pichia yeast expression system as the capture antigen.The serum samples were collected from the same group of 35 DENV-1 patients of primary infection during disease period in 2006 and their follow-up phase in 2010; and the sensitivity of the assay was compared to that of the commercial Panbio DENV IgG ELISA.Results The sensitivity of DENV ED Ⅲ IgG ELISA in detecting the serum samples from disease period and follow-up phase was 87％(20/23) and 94％ (33/35),respectively; whereas the sensitivity of Panbio DENV IgG ELISA was 71％(25/35) and 0,respectively.The sensitivity of DENV EDⅢ IgG ELISA in detecting the serum samples from both periods was similar,without statistical significance (x2 =0.946,P =0.331).For serum samples from disease period,the sensitivity of DENV ED Ⅲ IgG ELISA was comparable with that of Panbio DENV IgC ELISA (x2 =1.924,P =0.165).However,DENV ED Ⅲ IgG ELISA demonstrated a significantly higher sensitivity than Panbio DENV IgG ELISA in detecting the serum samples from follow-up phase (x2 =62.432,P =0.000).Conclusion DENV ED Ⅲ IgG capture ELISA is highly sensitive in detecting IgG in the serum samples from either disease period or follow-up phase.This method might be a promising alternative for diagnosis and seroepidemiologic survey of dengue. Key words: Dengue virus; Immunoglobulin G; Enzyme-linked immunosorbent assay; Serologic tests; Viral envelope proteins