We propose to develop a nucleic acid based point-of-care diagnostic for quantifying viral load (VL) in whole blood. The technology makes use of rapid RNA purification and reverse transcription recombinase polymerase amplification (RT-RPA) on an electrokinetic paper device for quantitative detection of HIV-1 RNA in less than 15 minutes. This technology development is generally applicable to viral diagnostics in complex biological samples, and here we focus on HIV-1 where no cost effective nucleic acid-based tests for point-of-care diagnostics are available. The HIV/AIDS epidemic is a major global health challenge, and is a leading cause of mortality and burden over the last decade. Initiation of antiretroviral therapy (ART) can maintain durable viral suppression, however viral load (VL) tests are needed to monitor the ongoing effectiveness of therapy, especially in prevention of mother to child transmission of HIV. Currently, the optimal tests for measuring HIV VL rely on molecular amplification methods that detect either HIV RNA or proviral DNA. A variety of commercial nucleic acid amplification technologies (NAATs) assays are available for these purposes but their complexity, sensitive reagents, cost, and hardware are prohibitively expensive and typically necessitate a fully functional centralized laboratory for their use. The logistics around specimen collection, testing, and transport results in delayed diagnosis (from 9 days to 5 months), diminished follow up with patients/guardians, and lost opportunity for life saving treatment. We propose an electrokinetic paper based nucleic acid amplification assay that can quantify HIV VL from whole blood in 15 minutes, with minimal user intervention, and no moving parts. Our innovative paper-based approach combines rapid extraction of RNA by isotachophoresis (ITP) with RT-RPA amplification of target nucleic acids. The diagnostic platform has integrated sample prep using a blood separation membrane, surfactant based virion lysis, and ITP RNA purification. ITP extracts the nucleic acid targets from fractionated plasma while focusing the RNA with RT-RPA reagents to accelerate the amplification reactions. The RPA reactions are quantified using fluorescence intensity and an internal control reaction. A mobile phone is used to power and control the extraction and reaction, measure the RPA reaction fluorescence, analyze the fluorescence data, and unambiguously report the VL to the clinician and transmit to the cloud. The platform will provide quantification of HIV VL in 15 minutes, for less than $10 per test, and minimal user intervention. The diagnostic will be validated over a wide range of HIV subtypes and evaluated using clinical whole blood samples from HIV/AIDS patients.
Projective Narrative The HIV/AIDS epidemic is a leading cause of mortality and burden over the last decade and quantification of HIV viral load (VL) is required for treatment by antiretroviral therapy to maintain durable viral suppression. No point-of-care diagnostic is available for HIV viral load and current tests for measuring HIV VL rely on molecular amplification methods that detect either HIV RNA, but their complexity, sensitive reagents, cost, and hardware necessitates a centralized laboratory for their use, which results in delayed diagnosis (from 9 days to 5 months), diminished follow up with patients/guardians, and lost opportunity for life saving treatment. We propose a novel electrokinetic paper based nucleic acid amplification point-of-care diagnostic that can quantify HIV viral load in whole blood in 15 minutes, with minimal user intervention, and no moving parts, that is broadly applicable to many diseases that require diagnosis and monitoring at the point-of-care.
