A universal point-of-care immunochromatographic test for the serodiagnosis of hepatitis D

Hepatitis D is estimated to affect 12 million people worldwide and is caused by the hepatitis D virus (HDV), a defective virus that requires the presence of the hepatitis B virus (HBV) for infection. Here, we report a new recombinant antigen (DTH10.1) to detect anti-HDV IgG antibodies, designed to include a consensus sequence of the HDV antigen, based on bioinformatic analysis of the eight HDV genotypes. Using serum samples from patients living in the endemic area of the Brazilian Amazon basin, the enzyme-linked immunosorbent assay (ELISA) based on this protein displayed a sensitivity of 90.6% (95% CI: 84.2%-94.5%) and a specificity of 100% (95% CI: 94.2%-100.0%), while a rapid immunochromatographic test (ICT) showed a sensitivity of 91.3% (95% CI: 85.0%-95.1%) and specificity of 99.0% (95% CI: 94.5%-99.95%). Commercial monoclonal antibodies for HBV surface antigen (HBsAg) detection were then added to the test, resulting in a multiplex ICT with a sensitivity of 87.1% (95% CI: 81.3%-91.4%) for HBsAg and 95.2% (95% CI: 90.0%-97.8%) for anti-HDV IgG and specificity of 100% (95% CI: 91.0%-100.0%) and 98.0% (95% CI: 92.9%-99.6%), respectively. Finally, the three tests were evaluated against a panel of 79 patient samples infected, covering the eight HDV genotypes. The results indicated that all the DTH10.1-based tests were able to detect anti-IgG HDV antibodies with high sensitivity and specificity, regardless of the infecting HDV genotype. In conclusion, the prototypes developed for serodiagnosis of HDV using the DTH10.1 recombinant protein are promising tools for the universal diagnosis of HDV infection.IMPORTANCEThe manuscript outlines the complete strategy for developing tools for the diagnosis of hepatitis D, including an enzyme-linked immunosorbent assay (ELISA), an immunochromatographic test (ICT), and a multiplex ICT for the simultaneous detection of hepatitis B virus surface antigen and anti-hepatitis D virus (HDV) IgG antibodies. All the tests described are capable of detecting all eight HDV genotypes with high accuracy.