Use of bDNA testing in the immunologically nonresponding patient who has a low or undetectable viral load by RT-PCR testing.
BACKGROUND
Studies have shown that reverse transcription-polymerase chain reaction (RT-PCR) technology underquantifies viral loads in patients with non-B clades of HIV-1. Testing with bDNA technology gave higher viral loads in these subtypes. A study was conducted to determine whether virologically responding patients on HAART who were not immunologically responding would have higher viral loads using bDNA technology and whether these differences were due to non-B clades.


METHODS
Forty-eight patients receiving HAART for more than 6 months who were having inappropriate immunologic responses in spite of undetectable or very low viral loads determined by RT-PCR (<3000 copies by Roche Amplicor 1.0) were studied. These patients had bDNA viral loads performed. All patients who had bDNA viral loads equivalent to >3000 by RT-PCR had clade and genotypic studies performed.


RESULTS
Fifteen patients had viral loads by bDNA that were equivalent to >3000 copies by RT-PCR. Four of these were found to have non-B clades (one D clade and three AG clade). The D clade patient had multidrug resistance; none of the AG clade patients had resistance. Of the remaining 11 patients, virus could not be recovered from 2 and 9 had a B clade. Six of these nine had genotypic resistance to HAART drugs.


CONCLUSIONS
bDNA testing may be useful in the immunologically nonresponding patient.
Grimes
Richard M
RM
School of Public Health, The University of Texas Health Science Center at Houston, USA. rgrimes@sph.uth.tmc.edu
Lewis
Stanley T
ST
Visnegarwala
Fehmida
F
Goodly
Joseph
J
Sutton
Richard
R
Rodriguez-Barradas
Maria
M
D000328:Adult; D019380:Anti-HIV Agents / Q000494:pharmacology / Q000627:therapeutic use; D023241:Antiretroviral Therapy, Highly Active; D021121:Branched DNA Signal Amplification Assay / Q000379:methods*; D024882:Drug Resistance, Viral; D005260:Female; D006678:HIV / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification*; D015658:HIV Infections / Q000188:drug therapy / Q000276:immunology* / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019562:Viral Load
D019380:Anti-HIV Agents