A rapid, quantitative point-of-care diagnostics method for viral load detection of HIV-1 clades A, B, C, D, and G
HIV infection remains an international health crisis, where it is especially acute in sub-Saharan Africa, despite the development of antiretroviral therapy. High sensitivity, point-of-care clinical diagnostic tests for detecting and quantifying HIV viral load are lacking in development, particularly for resource-limited settings.
Existing technologies are immunoassay-based, which are not quantitative and do not allow for early detection prior to seroconversion or in neonates. Reverse-transcription loop-mediated isothermal amplification (RT-LAMP) amplifies cDNA. The amplicons can be detected by various methods, including intercalating fluorescent dye.
Researchers in the Bushman and Bau labs have improved existing HIV RT-LAMP assays to detect HIV subtypes A, B, C, D, and G, of which A and C are prevalent in Africa and India. A bioinformatics study identified highly conserved sequences within the HIV genome, followed by the design and optimization of primers, targeting the HIV integrase coding region. The work culminated in a rapid quantitative assay, with clinical samples currently being tested.
The fluorescence-based DNA detection time is less than 20 minutes for amplifying more than 5,000 copies of nucleic acid. In combination with a microfluidic diagnostic chip, a smart cup, consisting of a Thermos cup, a 3D printed cup lid, chip holder, and smartphone holder, designed by the Bau lab can be employed to detect the amplified nucleic acids in a minimally-instrumented format.