Evaluation of HIV-1 Viral Load Detection by modified a Commercial Real-Time PCR Reagent used for Light Cycler 1.2 Instrument
Sumonmal Uttayamakul MSc*, Sirirat Likanonsakul MSc*, Ruengpung Sutthent MD, PhD**, Achara Chaovavanich MD*
Affiliation : * Bamrasnaradura Infectious Disease Institute, Department of Disease Control, Ministry of Public Health, Nonthaburi ** Department of Microbiology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok
Objective : Commercial TaqMan real-time PCR reagent was modified and applied on Light Cylcer 1.2 for
quantifying HIV-1 RNA in plasma and compared with the reference method; COBAS AmpliPrep/COBAS Amplicor
HIV-1 monitor test version 1.5.
Materials and Methods : Three hundred and eight frozen and fresh plasma samples were used for evaluation.
Sequential specimens were also tested for follow-up cases.
Results : The correlation between HIV-1 RNA values obtained by reference and modified method with auto-
mated and manual sample preparation were significant with r = 0.916 and 0.908 (p < 0.001, p < 0.001)
respectively with similar agreement log of mean bias (0.5 versus 0.48). High degree of correlation and
agreement were observed between the assays in blind fresh plasma, r = 0.953 (p < 0.001) with 0.15 log
difference in HIV-1 RNA level. Among follow-up samples, both methods gave 100% concordant results.
Conclusion : This modified protocol provided evidence for using modified commercial real-time PCR reagent
for HIV-1 RNA quantitative detection as a monitoring tool for HIV/AIDS patients in Thailand.
Keywords : HIV-1 viral load, ARV monitoring: real-time PCR, Light Cycler
