Sensitive and Quantitative Point-of-Care HIV Viral Load Quantification from Blood Using a Power-Free Plasma Separation and Portable Magnetofluidic Polymerase Chain Reaction Instrument

Abstract

Point-of-care (POC) HIV viral load (VL) tests are needed to enhance access to HIV VL testing in low-and middleincome countries (LMICs) and to enable HIV VL self-testing at home, which in turn have the potential to enhance the global management of the disease. While methods based on real-time reverse transcription-polymerase chain reaction (RT-PCR) are highly sensitive and quantitatively accurate, they often require bulky and expensive instruments, making applications at the POC challenging. On the other hand, although methods based on isothermal amplification techniques could be performed using lowcost instruments, they have shown limited quantitative accuracies, i.e., being only semiquantitative. Herein, we present a sensitive and quantitative POC HIV VL quantification method from blood that can be performed using a small power-free three-dimensionalprinted plasma separation device and a portable, low-cost magnetofluidic real-time RT-PCR instrument. The plasma separation device, which is composed of a plasma separation membrane and an absorbent material, demonstrated 96% plasma separation efficiency per 100 μL of whole blood. The plasma solution was then processed in a magnetofluidic cartridge for automated HIV RNA extraction and quantification using the portable instrument, which completed 50 cycles of PCR in 15 min. Using the method, we achieved a limit of detection of 500 HIV RNA copies/mL, which is below the World Health Organization's virological failure threshold, and a good quantitative accuracy. The method has the potential for sensitive and quantitative HIV VL testing at the POC and at home self-testing.

Rapid and Portable Quantification of HIV RNA via a Smartphone-enabled Digital CRISPR Device and Deep Learning

“…First, as our device currently only detects HIV RNA, sample preparation (e.g., HIV RNA extraction) still needs to be incorporated. To this end, nucleic acid extraction based on magnetic beads (Fan et al, 2023;Jiang et al, 2023;Kang et al, 2021;Ngo et al, 2023;Pearlman et al, 2020;Trick et al, 2022), cellulose paper (Zou et al, 2017), or FTA membrane (Kadimisetty et al, 2021;Ndunguru et al, 2005) offer possible solutions. It may also be feasible to adopt a custom digital chip with integrated nucleic acid extraction capability (Yin et al, 2020).…”

Recent Advances in Molecular and Immunological Diagnostic Platform for Virus Detection: A Review

“…The magnetofluidic cartridge ensured transportation of the sample for nucleic acid purification and amplification. In another study, a platform for sensitive POC HIV load quantification was developed ( Figure 6 a) [ 88 ]. HIV can be quantified from the blood.…”

“…**** indicates p < 0.0001. Reprinted with permission from [ 88 ]. Copyright (2022) ACS publications.…”

Compact Point-of-Care Device for Self-Administered HIV Viral Load Tests from Whole Blood

“…Typically, these devices utilize plasma as the specimen for testing, extracted from venipuncture whole blood within a controlled laboratory environment. As a result of this requirement, these instruments are not particularly suited for self-administered testing procedures, where more readily accessible sample types such as finger-prick whole blood would be more desirable. − In the domain of quantitative POC HIV self-testing, there have been efforts, though limited, to create and optimize systems . The majority of these methodologies are dependent on complex, high-cost analyzers and opt for the use of portable thermal cyclers instead of traditional real-time PCR machinery …”

“…15−17 In the domain of quantitative POC HIV self-testing, there have been efforts, though limited, to create and optimize systems. 18 The majority of these methodologies are dependent on complex, high-cost analyzers and opt for the use of portable thermal cyclers instead of traditional real-time PCR machinery. 19 Isothermal amplification technologies, such as reverse transcription loop-mediated isothermal amplification (RT-LAMP), have seen increased adoption in POC settings.…”