AUTHOR=Franco Gabriela de Melo , Rocha Anderson Santos da , Cox Laura Jorge , Daian e Silva Danielle Soares de Oliveira , da Silveira e Santos Débora Marques , Martins Marina Lobato , Romanelli Luis Claudio , Ishak Ricardo , Vallinoto Antonio C. R. , Bomfim Maria Rosa Q. , Caterino-de-Araujo Adele , Coelho-dos-Reis Jordana G. A. , da Fonseca Flávio Guimarães  , Barbosa-Stancioli Edel Figueiredo 

TITLE=Multi-Epitope Protein as a Tool of Serological Diagnostic Development for HTLV-1 and HTLV-2 Infections

JOURNAL=Frontiers in Public Health

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2022.884701

DOI=10.3389/fpubh.2022.884701

ISSN=2296-2565

ABSTRACT=<p>A multi-epitope protein expressed in a prokaryotic system, including epitopes of Env, Gag, and Tax proteins of both HTLV-1 and HTLV-2 was characterized for HTLV-1/2 serological screening. This tool can contribute to support the implementation of public policies to reduce HTLV-1/2 transmission in Brazil, the country with the highest absolute numbers of HTLV-1/2 infected individuals. The chimeric protein was tested in EIA using serum/plasma of HTLV-infected individuals and non-infected ones from four Brazilian states, including the North and Northeast regions (that present high prevalence of HTLV-1/2) and Southeast region (that presents intermediate prevalence rates) depicting different epidemiological context of HTLV-1/2 infection in our country. We enrolled samples from Pará (<italic>n</italic> = 114), Maranhão (<italic>n</italic> = 153), Minas Gerais (<italic>n</italic> = 225) and São Paulo (<italic>n</italic> = 59) states; they are from blood donors' candidates (Pará and Minas Gerais), pregnant women (Maranhão) and HIV+/high risk for sexually transmitted infection (STI; São Paulo). Among the HTLV-1/2 positive sera, there were co-infections with viral (HTLV-1 + HTLV-2, HIV, HCV, and HBV), bacterial (<italic>Treponema pallidum</italic>) and parasitic (<italic>Trypanosoma cruzi, Schistosma mansoni, Strongyloides stercoralis, Entamoeba coli, E. histolytica</italic>, and <italic>Endolimax nana</italic>) pathogens related to HTLV-1/2 co-morbidities that can contribute to inconclusive diagnostic results. Sera positive for HIV were included among the HTLV-1/2 negative samples. Considering both HTLV-1 and HTLV-2-infected samples from all states and different groups (blood donor candidates, pregnant women, and individuals with high risk for STI), mono or co-infected and HTLV-/HIV+, the test specificity ranged from 90.09 to 95.19% and the sensitivity from 82.41 to 92.36% with high accuracy (ROC AUC = 0.9552). This multi-epitope protein showed great potential to be used in serological screening of HTLV-1 and HTLV-2 in different platforms, even taking into account the great regional variation and different profile of HTLV-1 and HTLV-2 mono or co-infected individuals.</p>