High prevalence of primary Enfuvirtide (ENF) resistance-associated mutations in HIV-1-infected patients in Hong Kong

J Clin Virol. 2010 Mar;47(3):273-5. doi: 10.1016/j.jcv.2010.01.002. Epub 2010 Jan 29.


Background: Enfuvirtide (ENF) is a viral fusion inhibitor used in patients failing highly active antiretroviral therapy (HAART). Mutations associated with ENF resistance have been identified within amino acid positions 36-45 of gp41. As ENF will be introduced to Hong Kong, an understanding of the prevalence of naturally occurred ENF resistance mutations is important before implementation of ENF treatment.

Objectives: To investigate the prevalence of ENF resistance-associated mutations in the HR1 and HR2 of HIV-1 strains obtained from ENF-naïve patients.

Study design: HIV-1 strains isolated from 185 patients (156 antiretroviral treatment [ART]-naïve and 29 HAART-experienced) were screened for ENF resistance-associated mutations using RT-PCR and DNA sequencing.

Results: Primary mutations were detected in 19.4% of HARRT-experienced patients and 20.5% of ART-naïve patients. G36D was encountered most frequently and more prevalent in non-B subtypes. N42S, L54M and V69I were the major polymorphisms detected. N42S and L54M were predominant in CRF01_AE and subtype B, respectively. V69I was found in all samples harboring G36D. In three longitudinal samples from an ENF-treated patient, G36D was detected after ENF treatment for 6 months and the mutation persisted after termination of ENF for 6 months.

Conclusions: The high prevalence of ENF resistance-associated mutations in HARRT-experienced and ART-naïve patients identified in this study highlights the importance of mutation screening before ENF therapy in Hong Kong. Our findings from the ENF-treated patient showed that G36D mutation persisted as long as 6 months after ENF withdrawal. Phenotypic assays will be necessary to confirm the influence of this mutation to ENF susceptibility.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-HIV Agents / pharmacology*
  • Drug Resistance, Viral*
  • Enfuvirtide
  • HIV Envelope Protein gp41 / genetics
  • HIV Envelope Protein gp41 / pharmacology*
  • HIV Infections / virology*
  • HIV-1 / drug effects*
  • HIV-1 / genetics*
  • HIV-1 / isolation & purification
  • Hong Kong
  • Humans
  • Mutation, Missense*
  • Peptide Fragments / pharmacology*
  • Prevalence
  • RNA, Viral / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Analysis, DNA


  • Anti-HIV Agents
  • HIV Envelope Protein gp41
  • Peptide Fragments
  • RNA, Viral
  • gp41 protein, Human immunodeficiency virus 1
  • Enfuvirtide