Establishment of enzyme-linked immunosorbent assay one-step assay based on recombinant proteins derived from different genotypes of hepatitis E virus / 中华传染病杂志

ABSTRACT

Objective To establish an anti-hepatitis E virus (HEV) enzyme-linked immunosorbent assay (ELISA) one-step assay based on seven glutathione S-transferase (GST)-fusion recombinant proteins derived from different HEV genotypes and subtypes. Methods Concentration of the coating antigen was optimized by block titration. The cut-off values were determined for anti-HEV IgG and IgM, respectively. Assay sensitivity, specificity and reproducibility were investigated using samples with confirmed anti-HEV positive. Results An optimal concentration of mixture of recombinant proteins (Mix166) was 1.5 mg/L for antigen coating. Coefficient of variations (CV) of anti-HEV within-run and between-run were 8.67% and 10.85%, respectively. CV of anti-HEV IgM within-run and between-run were 4.56% and 5.99%, respectively. Positive rates of anti-HEV IgG and IgM were both 94% for 50 HEV-polymerase chain reaction (PCR) positive sera tested with the one step assay. Using one-step assay to detect 674 serum samples from healthy people, 52 samples were found anti-HEV IgG positive and 3 samples were anti-HEV lgM positive. A series of serum specimens collected at different time points until 76 weeks from a chimpanzee challenged with HEV Mexican strain were anti-HEV IgM positive during week 1--6 and anti-HEV IgG positive during week 2--76 determined by the one step ELISA. However, import ELISA kits were lack of both the IgM and lgG reactivity to all of the serial chimpanzee sera. Conclusions The sensitivity and specificity of anti-HEV ELISA one-step assay based on the Mix166 antigen are high and could be used for the diagnosis of HEV infection.