Evaluation efficacy of dried blood spot filter paper for HIV-1 viral load and Drug resistance genotyping detection

Abstract

Currently, although a number of HIV-1 infected people increases continuously, the number of death people caused by HIV-1 disease reduces as compared to the death people in the past. Because patient is monitored continually by detecting the HIV-1 viral load and HIV-1 drug resistance, which is used to guide a HIV-1 therapy. In addition, a dried blood spot (DBS), which is used for collecting sample, is used for detecting the viral load and drug resistance genotyping because it is convenience to be collected and transported to both urban and rural area. Whatman 903 (W-903) filter paper has been used to detect HIV-1 viral load and HIV-1 drug resistance. However, the cost of Whatman 903 filter paper is still expensive. The objective of this research was to evaluate the performance of two new dried blood spot filter papers, nitrocellulose membrane and cellulose fiber sample pad, which cost is cheaper than Whatman 903 filter paper for collecting the dried blood spot in order to be used to detect HIV-1 load and HIV-1 drug resistance. The dried blood spot specimens were collected from 70 blood samples which HIV-1 viral load and HIV-1 drug resistance were measured by NucliSENS EasyQ HIV-1 v2.0 and ViroSeq HIV-1 Genotyping system, respectively. Moreover, we also evaluated an ability of gold nanoparticles and anion polymer-coated magnetic beads in order to increase the sensitivity of HIV-1 viral load detection of filter papers. The experimental results showed that nitrocellulose membrane was not capable of absorbing the dried blood spot therefore only Whatman 903 and cellulose fiber sample pad performance were evaluated. On the other hand, when used anion polymer-coated magnetic beads with filter papers, the HIV-1 viral load could not be interpreted. This is because the anion polymer-coated magnetic beads interfere the reaction in HIV-1 viral load detection. Although gold nanoparticles did not interfere the HIV-1 viral load detection reaction, the detected HIV-1 viral load from Whatman 903 with/without gold nanoparticles and cellulose fiber sample pad with/without gold nanoparticles were related. This means that gold nanoparticles did not affect an increasing in an ability of HIV-1 viral load detection. Since cellulose fiber sample pad could be used to detect the HIV-1 viral load similarly to Whatman 903, we therefore evaluated the performance of Whatman 903 and cellulose fiber sample pad to detect HIV-1 drug resistance from dried blood spot. The experimental results showed that these filters detected the amino sequencing which was the cause of virus mutation. Therefore, the performance of cellulose fiber sample pad should be investigated comprehensively in order to be used in practical.