Journal Article

Promising application of monoclonal antibody against chikungunya virus E1-antigen across genotypes in immunochromatographic rapid diagnostic tests

Suzuki, Keita, Barbé, Barbara, Huits, Ralph, van Esbroeck, Marjan, Iwamoto, Hisahiko, Phadungsombat, Juthamas, Nakayama, Emi E., Cnops, Lieselotte, van den Berg, Riemsdijk, Rahim, Rummana, Leaungwutiwong, Pornsawan, Hasan, Abu, Rahman, Mizanur, Shioda, Tatsuo, Tuekprakhon, Aekkachai

2020

Overview

Background Three different genotypes of chikungunya virus (CHIKV) have been classified: East/Central/South African (ECSA), West African (WA), and Asian. Previously, a rapid immunochromatographic (IC) test detecting CHIKV E1-antigen showed high sensitivity for certain ECSA-genotype viruses, but this test showed poor performance against the Asian-genotype virus that is spreading in the American continents. We found that the reactivity of one monoclonal antibody (MAb) used in the IC rapid diagnostic test (RDT) is affected by a single amino acid substitution in E1. Therefore, we developed new MAbs that exhibited specific recognition of all three genotypes of CHIKV. Methods Using a combination of the newly generated MAbs, we developed a novel version of the IC RDT with improved sensitivity to Asian-genotype CHIKV. To evaluate the sensitivity, specificity, and cross-reactivity of the new version of the IC RDT, we first used CHIKV isolates and E1-pseudotyped lentiviral vectors. We then used clinical specimens obtained in Aruba in 2015 and in Bangladesh in 2017 for further evaluation of RDT sensitivity and specificity. Another alphavirus, sindbis virus (SINV), was used to test RDT cross-reactivity. Results The new version of the RDT detected Asian-genotype CHIKV at titers as low as 10^4 plaque-forming units per mL, a concentration that was below the limit of detection of the old version. The new RDT had sensitivity to the ECSA genotype that was comparable with that of the old version, yielding 92% (92 out of 100) sensitivity (95% confidence interval 85.0–95.9) and 100% (100 out of 100) specificity against a panel of 100 CHIKV-positive and 100 CHIKV-negative patient sera obtained in the 2017 outbreak in Bangladesh. Conclusions Our newly developed CHIKV antigen-detecting RDT demonstrated high levels of sensitivity and lacked cross-reactivity against SINV. These results suggested that our new version of the CHIKV E1-antigen RDT is promising for use in areas in which the Asian and ECSA genotypes of CHIKV circulate. Further validation with large numbers of CHIKV-positive and -negative clinical samples is warranted. (323 words).

• Publisher: BioMed Central,BioMed Central Ltd,Springer Nature B.V,BMC
• Subject: Amino acid substitution / Amino acids / Animals / Antibodies, Monoclonal - immunology / Antibodies, Viral - blood / Antigen-antibody reactions / Antigens / Antigens, Viral - immunology / Aruba / Asian genotype / Bangladesh / Biological products industry / Biomedical and Life Sciences / Biomedicine / Chikungunya Fever - diagnosis / Chikungunya virus / Chikungunya virus - classification / Chikungunya virus - genetics / Chlorocebus aethiops / Chromatography, Affinity / confidence interval / cross reaction / Cross Reactions / Cross-reactivity / detection limit / diagnostic techniques / Diagnostic tests / E1 protein / ECSA / Genotype / Genotype & phenotype / Genotypes / HEK293 Cells / Humans / immunoaffinity chromatography / Immunologic Tests / Medical tests / Monoclonal antibodies / Monoclonal antibody / Pathogens / patients / Plasmids / Positive-strand RNA viruses / Proteins / Public health / Rapid immunochromatographic RDT / rapid methods / Sensitivity analysis / Sensitivity and Specificity / Sindbis virus / Vero Cells / Viral Envelope Proteins - genetics / Viral Envelope Proteins - immunology / Virology / Viruses