title: Web resources for HIV type 1 genotypic-resistance test interpretation.
abstract: Interpreting the results of plasma human immunodeficiency virus type 1 (HIV-1) genotypic drug-resistance tests is one of the most difficult tasks facing clinicians caring for HIV-1-infected patients. There are many drug-resistance mutations, and they arise in complex patterns that cause varying levels of drug resistance. In addition, HIV-1 exists in vivo as a virus population containing many genomic variants. Genotypic-resistance testing detects the drug-resistance mutations present in the most common plasma virus variants but may not detect drug-resistance mutations present in minor virus variants. Therefore, interpretation systems are necessary to determine the phenotypic and clinical significance of drug-resistance mutations found in a patient's plasma virus population. We describe the scientific principles of HIV-1 genotypic-resistance test interpretation and the most commonly used Web-based resources for clinicians ordering genotypic drug-resistance tests.
authors.affiliation: Division of Infectious Diseases, Stanford University, Stanford, California 94301, USA.
authors.forename: Tommy F
authors.initials: TF
authors.lastname: Liu
authors.forename: Robert W
authors.initials: RW
authors.lastname: Shafer
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology*; D024921:Drug Resistance, Multiple, Viral / Q000235:genetics*; D005838:Genotype; D015658:HIV Infections / Q000821:virology*; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D020407:Internet
chemical_list: D019380:Anti-HIV Agents