title: Antiretroviral drug resistance, HIV-1 tropism, and HIV-1 subtype among men who have sex with men with recent HIV-1 infection.
abstract: OBJECTIVE
  Antiretroviral drug treatment may be complicated in individuals infected with antiretroviral drug-resistant or non-subtype B HIV-1 strains. HIV-1 tropism may also affect disease progression. We analyzed antiretroviral drug resistance, HIV-1 subtype, and HIV-1 tropism among 195 men who have sex with men from six major cities in the United States, using samples collected within 6 months of HIV-1 seroconversion (1999-2003).
  
  
  METHODS
  HIV-1 genotyping was performed using the ViroSeq HIV-1 Genotyping System. HIV-1 tropism was determined using a commercial assay. HIV-1 subtyping was performed by phylogenetic analysis of pol region sequences.
  
  
  RESULTS
  Thirty-one (15.9%) of the men had evidence of antiretroviral drug resistance. Seven (3.6%) men had multi-class resistance, including three (1.5%) with resistance to all three antiretroviral drug classes. We found no statistically significant association of antiretroviral drug resistance with demographic factors, sexual practices, self-reported sexually transmitted infections, use of recreational drugs, or use of antiretroviral drug post-exposure prophylaxis. All samples were HIV-1 subtype B. Four men had CXCR4-using HIV-1 strains. One man with a CXCR4-using strain also had antiretroviral drug resistance.
  
  
  CONCLUSIONS
  Antiretroviral drug resistance is relatively common among recently infected men who have sex with men in the United States. CXCR4-using strains were detected in a small number of these infections, which were all subtype B HIV-1.
authors.affiliation: Department of Pathology, Johns Hopkins University School of Medicine, The Johns Hopkins Medical Institutions, 720 Rutland Avenue, Baltimore, MD 21205, USA. seshlem@jhmi.edu
authors.forename: Susan H
authors.initials: SH
authors.lastname: Eshleman
authors.forename: Marla
authors.initials: M
authors.lastname: Husnik
authors.forename: Sarah
authors.initials: S
authors.lastname: Hudelson
authors.forename: Deborah
authors.initials: D
authors.lastname: Donnell
authors.forename: Yijian
authors.initials: Y
authors.lastname: Huang
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Stephen
authors.initials: S
authors.lastname: Hart
authors.forename: Brooks
authors.initials: B
authors.lastname: Jackson
authors.forename: Thomas
authors.initials: T
authors.lastname: Coates
authors.forename: Margaret
authors.initials: M
authors.lastname: Chesney
authors.forename: Beryl
authors.initials: B
authors.lastname: Koblin
mesh_terms: D000293:Adolescent; D000328:Adult; D044966:Anti-Retroviral Agents / Q000627:therapeutic use*; D024882:Drug Resistance, Viral; D015751:Genes, pol / Q000235:genetics; D005838:Genotype; D015658:HIV Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000821:virology; D006679:HIV Seropositivity / Q000453:epidemiology / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000254:growth & development* / Q000378:metabolism; D018451:Homosexuality, Male; D006801:Humans; D008297:Male; D010802:Phylogeny; D019718:Receptors, CXCR4 / Q000378:metabolism; D018894:Reverse Transcriptase Inhibitors / Q000627:therapeutic use; D018523:Tropism / Q000502:physiology*; D014481:United States / Q000453:epidemiology
chemical_list: D044966:Anti-Retroviral Agents; D019718:Receptors, CXCR4; D018894:Reverse Transcriptase Inhibitors