Evaluation of the Aptima HIV-1 Quant Dx Assay for HIV-1 RNA Quantitation in Different Biological Specimen Types.

Background: The search for a cure for HIV infection has highlighted the need for increasingly sensitive and precise assays to measure viral burden in various tissues and body fluids. We describe the application of a standardized assay for HIV-1 RNA in multiple specimen types

Methods: The fully automated Aptima HIV-1 Quant Dx assay (Aptima assay) is FDA-cleared for blood plasma HIV-1 RNA quantitation. In this study, the Aptima assay was applied for the quantitation of HIV RNA in peripheral blood mononuclear cells (PBMC; n=72), seminal plasma (n=20), cerebrospinal fluid (CSF; n=36), dried blood spots (DBS; n=104) and dried plasma spots (DPS; n=104).

Results: The Aptima assay was equivalent to or better than commercial assays or validated in-house assays for the quantitation of HIV RNA in CSF and seminal plasma. For PBMC specimens, the sensitivity of the Aptima assay in the detection of HIV RNA decayed as background uninfected PBMC counts increased; proteinase K treatment demonstrated some benefit in restoring signal at higher levels of background PBMC. Finally, the Aptima assay yielded 100% detection rates of DBS in participants with plasma HIV RNA levels ≥35copies/mL, and 100% detection rates of DPS in participants with plasma HIV RNA levels ≥394 copies/mL.

Conclusion: The Aptima assay was equivalent to or better than commercial assays or validated in-house assays for the quantitation of HIV RNA in CSF and seminal plasma. For PBMC specimens, the sensitivity of the Aptima assay in the detection of HIV RNA decayed as background uninfected PBMC counts increased; proteinase K treatment demonstrated some benefit in restoring signal at higher levels of background PBMC. Finally, the Aptima assay yielded 100% detection rates of DBS in participants with plasma HIV RNA levels ≥35copies/mL, and 100% detection rates of DPS in participants with plasma HIV RNA levels ≥394 copies/mL.