Clinical utility of genotypic resistance tests for HIV-1-infected patients with low-level virological failure.

The usefulness of genotypic resistance tests (GRT) among HIV-1 patients with low-level virological failure (LLVF) was evaluated. Up to 78% of samples with <1,000 copies/ml were sequenced successfully. For samples with 50 to 200 copies/ml, the success rate was as high as 69%.

Impact of HIV-1 viral subtype on disease progression and response to antiretroviral therapy.

Background: Our intention was to compare the rate of immunological progression prior to antiretroviral therapy (ART) and the virological response to ART in patients infected with subtype B and four non-B HIV-1 subtypes (A, C, D and the circulating recombinant form, CRF02-AG) in an ethnically diverse population of HIV-1-infected patients in south London.

Methods: A random sample of 861 HIV-1-infected patients attending HIV clinics at King's and St Thomas' hospitals' were subtyped using an in-house enzyme-linked immunoassay and env sequencing. Subtypes were compared on the rate of CD4 cell decline using a multi-level random effects model.

Time trends in primary resistance to HIV drugs in the United Kingdom: multicentre observational study.

Objective: To examine whether the level of primary resistance to HIV drugs is increasing in the United Kingdom.

Design: Multicentre observational study.

Setting: All virology laboratories in the United Kingdom carrying out tests for HIV resistance as part of routine clinical care.

K65R and Y181C are less prevalent in HAART-experienced HIV-1 subtype A patients.

The vast majority of HIV-1 infections globally are caused by subtype A or C, although little is known about their drug resistance profiles. We found that HAART-experienced patients infected with subtype A had a lower prevalence of K65R and Y181C than those with subtypes B or C, despite similar exposure to antiretroviral agents that select for these mutations. If confirmed, this information may be important in the planning of antiretroviral regimens in patients infected with HIV-1 subtype A.

Genotyping of B and non-B subtypes of human immunodeficiency virus type 1.

Current HIV-1 genotyping assays were developed using subtype B viruses prevalent in Western countries. It is not clear whether these assays are appropriate for use among African patients, who are likely to be infected with non-B subtypes. We evaluated the Bayer TRUGENE HIV-1 genotyping (TG) assay using prospectively collected samples from HIV-1-infected individuals who acquired infection in either sub-Saharan Africa or the West (Europe, North America, and Australia).