title: HIV-1 genotypic and phenotypic resistance.
abstract: Antiretroviral failure caused by the development of drug resistance in HIV-1 is an increasingly common clinical problem. Two types of resistance assays are available to clinicians. Genotypic assays determine the presence of mutations associated with drug resistance. The interpretation of mutations is often complicated, however, and may require expert opinion. Phenotypic assays provide a direct measure of the drug susceptibility of the virus. The magnitude of increase, however, in viral drug inhibitory concentration that is predictive of clinical drug failure remains unknown for several antiretroviral drugs. The mutational patterns underlying resistance to each antiretroviral drug are often diverse, and cross-resistance patterns within each of the currently available classes are complex. Currently, resistance testing is recommended for patients who have virologic failure on an antiretroviral regimen. Furthermore, testing should also be considered in treatment-native patients when the prevalence of transmitted drug-resistant virus is expected to be high.
authors.affiliation: Department of Medicine, Infectious Diseases Division, University of Pittsburgh, Scaife Hall, Suite 818C, 3550 Terrace Street, Pittsburgh, PA 15261, USA. georgehanna@post.harvard.edu
authors.forename: George J
authors.initials: GJ
authors.lastname: Hanna
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000188:drug therapy / Q000821:virology; D019380:Anti-HIV Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D024882:Drug Resistance, Viral / Q000235:genetics*; D005838:Genotype; D015497:HIV-1 / Q000187:drug effects* / Q000235:genetics; D006801:Humans; D010641:Phenotype
chemical_list: D019380:Anti-HIV Agents