A novel high performing multiplex immunoassay Multi-HTLV for serological confirmation and typing of HTLV infections

Abstract

Background Human T-Cell Lymphotropic Viruses (HTLV) type 1 and type 2 account for an estimated 5 to 10 million infections worldwide and are transmitted through breast feeding, sexual contacts and contaminated cellular blood components. HTLV-associated syndromes are considered as neglected diseases for which there are no vaccines or therapies available, making it particularly important to ensure the best possible diagnosis to enable proper counselling of infected persons and avoid secondary transmission. Although high quality antibody screening assays are available, currently available confirmatory tests are costly and have variable performance, with high rates of indeterminate and non-typable results reported in many regions of the world. The objective of this project was to develop and validate a new high-performance multiplex immunoassay for confirmation and discrimination of HTLV-1 and HTLV-2 strains. Methodology/Principal findings The multiplex platform was used first as a tool to identify suitable antigens and in a second step for assay development. With data generated on over 400 HTLV-positive blood donors sourced from USA and French blood banks, we developed and validated a high-precision interpretation algorithm. The Multi-HTLV assay demonstrated very high performance for confirmation and strain discrimination with 100% sensitivity, 98.1% specificity and 100% of typing accuracy in validation samples. The assay can be interpreted either visually or automatically with a colorimetric image reader and custom algorithm, providing highly reliable results. Conclusions/Significance The newly developed Multi-HTLV is very competitive with currently used confirmatory assays and reduces considerably the number of indeterminate results. The multiparametric nature of the assay opens new avenues to study specific serological signatures of each patient, follow the evolution of infection, and explore utility for HTLV disease prognosis. Improving HTLV diagnostic testing will be critical to reduce transmission and to improve monitoring of seropositive patients.

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

“…Serological diagnostic for HTLV-1/2 infections include viral antigens encoded by structural and regulatory genes and methods available fall in two categories: the screening tests and those with the capacity to confirm and discriminate the HTLV-1 and HTLV-2 infections ( 27 , 28 ). Although efforts have been made around the world to improve the HTLV-1/2 tests, the confirmatory tests are costly and variable in performance according to regional and epidemiological profiles, generating considerable rates of indeterminate and untyped virus results ( 13 , 27 , 29 , 30 ).…”

Results of a sample-to-cutoff ratio using Abbott Architect rHTLV-I/II assay allow to predict detection of HTLV-1 and HTLV-2 proviral DNA by real-time PCR

“…It offers higher sensitivity and more accurate discrimination between HTLV-1 and HTLV-2 infections. In addition, PCR tests have been increasingly used for confirmation given the cost reduction of molecular biology reagents and the introduction of real-time PCR methods (qPCR) [19][20][21] . It is important to note that in Brazil, confirmatory tests are not mandatory in blood banks, and blood bags are discarded without confirming HTLV-1/2 infections.…”