Quantification of HIV-1 RNA is important in monitoring disease progression and response to antiretroviral therapy in individuals with HIV-1. Among the FDA-approved assays for quantifying HIV-1 RNA from plasma, a few have been tailored for use with dried blood spots (DBS), now incorporated in World Health Organization (WHO) protocols (Vojno et al., 2022, World Health Organization, 2014). There is good correlation between HIV-1 viral load (VL) values obtained from plasma and DBS samples (Taieb et al., 2016, Tang et al., 2017) with the caveat that sensitivity is impacted due to smaller sample volume of DBS samples. Some of the modified assays have LOD below the threshold of 1000 copies/mL recommended by the WHO to determine virological failure (Tang et al., 2017, World Health Organization, 2021). The major advantage of DBS is specimen stability and transport at ambient temperature; however, DBS require finger sticks and additional processing step (Aitken et al., 2015).

Tasso T20 (Tasso, Inc., Seattle, WA) (T20) is a finger stick-free, self-sampling device capable of at-home testing (Fig. 1). The T20 has multiple advantages over finger stick methods, including consistent blood volume, participant acceptability, less discomfort, and eliminating the need for sample drying (Solheim et al., 2021). T20 was designed for pharmacokinetic monitoring and bio-marker testing (Solheim et al., 2021, Wan et al., 2022), so the elution protocols focused on releasing proteins from the pods.

We adapted the elution protocols for RNA samples and performed an analytical evaluation of T20 with the m2000 RealTime HIV-1 DBS validated assay (Abbott Molecular Inc., Des Plaines, IL) (RealTime assay). Our objectives were to optimize HIV-1 RNA elution, evaluate analytical performance, determine analytical agreement by comparing T20 to DBS, and assess the HIV-1 RNA stability.