Rapid changes in human immunodeficiency virus type 1 RNA load and appearance of drug-resistant virus populations in persons treated with lamivudine (3TC)

J Infect Dis. 1995 Jun;171(6):1411-9. doi: 10.1093/infdis/171.6.1411.


The effect of the appearance of drug-resistant human immunodeficiency virus type 1 (HIV-1) on viral RNA load was studied in patients treated with the reverse transcriptase inhibitor lamivudine. During the first 12 weeks of treatment, HIV-1 RNA concentrations and amino acid changes in codon 184, causing high-level resistance to lamivudine, were determined in longitudinal serum samples from HIV-1 p24 antigen-positive and -negative patients. A marked decline in the amount of HIV-1 RNA (approximately 95% below baseline) and HIV-1 p24 antigen was observed within 2 weeks, followed by a rise that coincided with the appearance of lamivudine-resistant viruses in serum (isoleucine mutants initially, which were subsequently replaced by valine variants). After 12 weeks, a partial antiviral effect was observed despite the presence of a complete codon 184 mutant virus population in serum. This study shows that the rapid appearance of drug-resistant virus in serum is followed by an increase in viral RNA load.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD4 Lymphocyte Count
  • Drug Resistance, Microbial
  • HIV Core Protein p24 / analysis
  • HIV Infections / drug therapy*
  • HIV Infections / microbiology
  • HIV Reverse Transcriptase
  • HIV-1 / genetics*
  • Humans
  • Lamivudine
  • Longitudinal Studies
  • Male
  • RNA, Viral / metabolism*
  • Reverse Transcriptase Inhibitors
  • Zalcitabine / analogs & derivatives*
  • Zalcitabine / therapeutic use


  • HIV Core Protein p24
  • RNA, Viral
  • Reverse Transcriptase Inhibitors
  • Lamivudine
  • Zalcitabine
  • HIV Reverse Transcriptase