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Deenan Pillay

Publications and source records attributed to Deenan Pillay.

46 records · Page 3Linked to original sources
PubMed2002

Evolution of antiretroviral phenotypic and genotypic drug resistance in antiretroviral-naive HIV-1-infected children treated with abacavir/lamivudine, zidovudine/lamivudine or abacavir/zidovudine, with or without nelfinavir (the PENTA 5 trial).

PURPOSE AND METHODS: To describe the evolution of resistance to zidovudine (ZDV), lamivudine (3TC), abacavir (ABC) and nelfinavir (NFV), 113 previously untreated children in the PENTA 5 trial had resistance assayed at baseline, rebound and/or 24, 48, 72 weeks (VIRCO: phenotyping and genotyping with 'Virtual Phenotype' interpretation). RESULTS: At baseline, few reverse transcriptase mutations and no primary protease inhibitor mutations were observed. Time to detectable HIV-1 RNA with reduced phenotypic susceptibility to any drug was shortest in the ZDV+3TC arm (overall logrank P=0.02). Through a median follow-up of 55 weeks, at their last assessment 11 (28%), 16 (40%) and 13 (32%) children with detectable HIV-1 RNA and a resistance test available had mutations conferring resistance to none, one, or two or more trial drugs, respectively, according to the virtual phenotype. Reduced phenotypic susceptibility to ABC only occurred in the 3TC+ABC arm and required K65R and/or L74V in addition to M184V. NFV-resistant virus was selected slowly through D30N or L90M pathways, and selection of ZDV-resistant virus was rare. CONCLUSIONS: Selection of 3TC-resistant virus was most frequent, followed by NFV and/or ABC; selection of ZDV-resistant virus was rare. Importantly, although in vitro, ABC selects for M184V as the first mutation, ABC did not select for M184V when combined with ZDV without 3TC. The most sustained HIV-1 RNA response was in the 3TC+ABC arm, but mutations conferring reduced susceptibility to 3TC and/or ABC evolved more frequently if virological failure occurred with 3TC+ABC than with ZDV+ABC.

Acquired Immunodeficiency Syndrome↗
PubMed2002

Resistance tests: what do clinical trials tell us?

Few routine laboratory tests have been evaluated by randomised controlled trials. Nevertheless, a number of such studies have been undertaken for genotypic and phenotypic HIV drug resistance assays. They are all based on a structure whereby patients are randomised to receive resistance tests or none (standards of care) at the time of acute viral failure, with the primary end points being the proportion with undetectable viral load at a time point 1224 weeks following randomisation. In other words, these studies assess the benefit afforded to clinicians by resistance data. We show that these studies vary in their results, and identify the potential factors associated with such variation. Although most studies demonstrate a clinical benefit of resistance testing, we argue that the opportunity for undertaking further such studies is probably gone and that effort should be focused on identifying more precisely the factors which determine the most cost-effective use of these expensive tests.

Anti-HIV Agents↗
PubMedDate not supplied

HIV viral load: the myth of the undetectable?

There is a wealth of data supporting the use of viral load measurements to monitor therapy. Indeed, clinical drug trial endpoints routinely include the proportion of patients with a plasma viral load reduction of greater than 0.5 log(10), or greater than 1 log(10). Since a higher viral load reflects increased amounts of virus replication, it would seem desirable to reduce this replication as far as possible, so that the goal of therapy has become one of viral undetectability in plasma. However, virological suppression to undetectable levels is not an absolute determinant of outcome because recent observational cohort data suggest that any significant reduction of viral load is associated with clinical benefit. There are also technical problems when attempting to measure undetectability, with lower limits of detection of 400 or 50 RNA copies/ml of plasma being driven more by the performance of commercial assays than by any inherent cut-off value with proven prognostic significance. Furthermore, the obsession with undetectability has created the concept of the 'viral blip', or 'intermittent viraemia' commonly defined as a single viral load measurement of between 50 and 400 copies/ml, preceded and followed by consistent measurements of less than 50 copies/ml, in a patient receiving therapy. Such blips should be considered in the context of frequent transient changes in viral load which occur below the lower limit of detection by existing laboratory assays. In my view, there remains a misunderstanding about the importance ascribed to these relatively minor changes in lower detection limits, when considered against the background of virus within the body as a whole. I also consider other possible uses of HIV-1 quantification in clinical practice, such as identifying the inherent potency of antiviral regimens.

Anti-HIV Agents↗
PubMedDate not supplied

Drug resistance mutations in HIV-1.

The International AIDS Society-USA (IAS-USA) Drug Resistance Mutations Group is a volunteer panel of experts that meets regularly to review and interpret new data on HIV-1 resistance. The focus of the group is to identify mutations associated with clinical resistance to HIV-1. These mutations have been identified by 1 or more of the following criteria: (1) in vitro passage experiments or validation of contribution to resistance by using site-directed mutagenesis; (2) susceptibility testing of laboratory or clinical isolates; (3) genetic sequencing of viruses from patients in whom the drug is failing; (4) correlation studies between genotype at baseline and virologic response in patients exposed to the drug. Drugs that have been approved by the US Food and Drug Administration (FDA) or available through expanded access protocols are included.

Anti-HIV Agents↗
PubMedDate not supplied

Update of the Drug Resistance Mutations in HIV-1: 2005.

Since 2000, the International AIDS Society-USA (IAS-USA) Drug Resistance Mutations Group has worked as an independent entity and forged a collaborative process to identify key HIV-1 drug resistance mutations. The goal of the group is to quickly deliver accurate and unbiased information to clinical practitioners on HIV-1 resistance. This April 2005 version of the IAS-USA Drug Resistance Mutations Figures replaces the version published in this journal in October 2004. The IAS-USA Drug Resistance Mutations Figures are designed for use in identifying mutations associated with viral resistance to antiretroviral drugs and in making therapeutic decisions. Care should be taken when using this list of mutations for surveillance or epidemilogic studies of transmission of drug-resistant virus. A number of amino acid substitutions, particularly minor mutations, represent polymorphisms that, in isolation, may not reflect prior drug selective pressure or reduced drug susceptibility.

Anti-HIV Agents↗
PubMedDate not supplied

Update of the drug resistance mutations in HIV-1: Fall 2005.

The International AIDS Society-USA (IAS-USA) Drug Resistance Mutations Group is marking 5 years as an independent volunteer panel of experts focused on identifying key HIV-1 drug resistance mutations. The goal of the effort is to quickly deliver accurate and unbiased information on these mutations to HIV clinical practitioners. The October/November 2005 version of the IAS-USA Drug Resistance Mutations Figures replaces the version published in this journal in March/April 2005. The IAS-USA Drug Resistance Mutations Figures are designed for use in identifying mutations associated with viral resistance to antiretroviral drugs and in making therapeutic decisions. Care should be taken when using this list of mutations for surveillance or epidemiologic studies of transmission of drug-resistant virus. A number of amino acid substitutions, particularly minor mutations, represent polymorphisms that in isolation may not reflect prior drug selective pressure or reduced drug susceptibility.

Anti-HIV Agents↗
PubMedDate not supplied

Update of the drug resistance mutations in HIV-1: Fall 2006.

The International AIDS Society-USA (IAS-USA) Drug Resistance Mutations Group is marking 6 years as an independent volunteer panel of experts focused on identifying key HIV-1 drug resistance mutations. The goal of the effort is to quickly deliver accurate and unbiased information on these mutations to HIV clinical practitioners. This version of the IAS-USA Drug Resistance Mutations Figures replaces the version published in this journal in October/November 2005. The IAS-USA Drug Resistance Mutations Figures are designed for use in identifying mutations associated with viral resistance to antiretroviral drugs and in making therapeutic decisions. Care should be taken when using this list of mutations for surveillance or epidemiologic studies of transmission of drug-resistant virus. A number of amino acid substitutions, particularly minor mutations, represent polymorphisms that in isolation may not reflect prior drug selective pressure or reduced drug susceptibility.

Anti-HIV Agents↗