This is a companion article to the feature, “Automating Molecular LDTs.”
Earlier this year, Rheonix Inc, Ithaca, NY, received a fast-track Small Business Innovation Research (SBIR) grant of approximately $1.7 million from the National Institute of Dental & Craniofacial Research (NIDCR) of the National Institutes of Health to develop a “dual use” assay capable of simultaneously detecting host anti-HIV antibodies and HIV viral RNA from either blood or saliva samples.1,2
NIDCR funded the work because of its interest in saliva-based assays and its desire to provide an easy-to-use and inexpensive testing platform for use in the developing world (see Figure 4).
Many healthcare professionals working in developing countries rely on simple test strip assays to detect the presence of anti-HIV antibodies in individuals. However, such resource-limited settings often lack the technical expertise or equipment necessary to confirm initial results with more-sensitive and -specific test methodologies.
Exploiting the capability of the Rheonix platform to simultaneously perform multiple functions, the dual use assay will not only provide immediate confirmation of a seropositive screening result by detecting the actual presence of viral RNA, but also will address the well-known “seroconversion window” during early HIV infection, when antibodies are not yet detectable. Since the seroconversion window can persist for weeks to a few months after initial infection—a period when viral loads are at their highest—the ability of the dual use assay to detect both anti-HIV antibodies and HIV viral RNA will help prevent early HIV infections from going undetected.
Most testing algorithms recommend confirming initial seropositive screening results, often with the use of a molecular diagnostic. But in the low-resource settings of developing countries, obtaining repeat specimens from individuals can be challenging or even impossible, since the individuals may not return for additional testing. The Rheonix platform overcomes this obstacle by using two different microfluidic pathways in the CARD cartridge, where either saliva or blood specimens can be simultaneously processed to detect anti-HIV antibodies and viral RNA using an isothermal amplification process.3
The ability to perform both assays simultaneously provides healthcare workers with a complete and accurate appraisal of an individual’s infection status in the earliest stages of disease. It represents an important tool for the “test and treat” and “treatment as prevention” approaches recommended by the World Health Organization for controlling the HIV epidemic.
Based on the success of these efforts against HIV, NIDCR recently added an administrative supplement to Rheonix’s SBIR grant, and encouraged the company to utilize the same underlying technology for the simultaneous detection of anti-Zika virus IgG, IgM antibodies, and viral RNA.4 Efforts are currently under way to design a Zika “dual assay” to run on Rheonix’s Encompass Optimum workstation, thus providing higher throughput that will make the assay suitable for use in reference labs once FDA clearance is obtained. Presently, neither the HIV nor Zika assays are cleared by FDA for in vitro diagnostic use.
- Rheonix receives fast-track grant from National Institutes of Health to simplify HIV testing [press release online]. Ithaca, NY: Rheonix, 2014. Available at http://rheonix.com/rheonix-receives-fast-track-grant-national-institutes-health-simplify-hiv-testing. Accessed August 18, 2016.
- Rheonix receives $1.5 million grant from the National Institute of Dental & Craniofacial Research to complete development of a rapid point-of-care test for HIV/AIDS [press release online]. Ithaca, NY: Rheonix, 2015. Available at: http://rheonix.com/rheonix-receives-1-5-million-sbir-phase-ii-grant-national-institute-dental-craniofacial-research-national-institutes-health-complete-development-rapid-point-care-te. Accessed August 12, 2016.
- Chen Z, Zhu H, Malamud D, et al. A rapid, self-confirming assay for HIV: simultaneous detection of anti-HIV antibodies and viral RNA. J AIDS Clin Res. 2016;7(1):540; doi: 10.4172/2155-6113.1000540.
- Rheonix to pursue rapid Zika virus diagnostic [press release online]. Ithaca, NY: Rheonix, 2016. Available at http://rheonix.com/rheonix-pursue-rapid-zika-virus-diagnostic. Accessed August 18, 2016.