[Utilities and limitations of a real-time PCR based assay for HIV-1 RNA quantification].
OBJECTIVE
This study evaluated the clinical utilities and limitations of HIV 1 RNA quantification using a real time PCR based assay, COBAS AmpliPrep/COBAS Taqman HIV 1 Test(TaqMan), since higher viral loads or wider fluctuations in viral loads have been demonstrated after this assay replaced COBAS AmpliPrep/AMPLICOR HIV-1 Monitor Version 1.5 Ultrasensitive (AMPLICOR).


RESULTS
We conducted a clinical study analyzing HIV-1 RNA levels measured by AMPLICOR assay and by TaqMan assay, CD4+ lymphocyte counts (CD4) and regimens of highly active antiretroviral therapy among patients who were treated in Tokyo Medical University Hospital. HIV 1 RNA levels were measured by an independent clinical laboratory (SRL, Inc.) outside the hospital. More than 50 copies/ml of HIV-1 RNA were demonstrated by TaqMan assay in 47% of 58 specimens in which HIV 1 RNA levels were undetectable (< 50 copies/ml) by AMPLICOR assay. TaqMan assay showed higher levels of HIV-1 RNA in comparison with AMPLICOR assay on correlation analysis. However, there was no tendency toward deterioration of either the serum HIV-1 RNA load or CD4 in patients showing discrepancies between the two assays. There was no correlation between the detection of HIV-1 RNA and the use of certain antiretroviral agents. Repeated assay of specimens from the same collection tube showed large discrepancies.


CONCLUSIONS
HIV 1 RNA quantification assay is essential to monitor the effects of antiretroviral therapy. Physicians must remain aware that the TaqMan assay is not yet sufficiently reliable.
Mihoko
M
Yotsumoto
Yasuyuki
Y
Yamamoto
Kagehiro
K
Amano
Katsuyuki
K
Fukutake
D019380:Anti-HIV Agents / Q000008:administration & dosage; D023241:Antiretroviral Therapy, Highly Active; D015415:Biomarkers / Q000097:blood; D003199:Computer Systems; D015658:HIV Infections / Q000175:diagnosis / Q000188:drug therapy / Q000821:virology; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods*; D012367:RNA, Viral / Q000097:blood*
D019380:Anti-HIV Agents; D015415:Biomarkers; D012367:RNA, Viral