Molecular characterization of hepatitis C virus for determination of subtypes and detection of resistance mutations to protease inhibitors in a group of intravenous drug users co-infected with HIV.
Modifications in therapeutic regimens for the treatment of hepatitis C virus (HCV) have been observed since the approval of viral protease inhibitors (PI), and the selection of natural drug-resistant variants has been also reported. Thus, it becomes crucial to be aware of consequences of new therapeutic approaches and make available tools for monitoring the infection. The study aimed to apply an "in-house" method for amplification and sequencing of the NS3 region which is the target of PI, and allowing simultaneously the classification of viral subtypes and identification of resistance mutations. Forty-seven samples collected from HIV injecting drug users and drug naive for HCV protease inhibitors were tested for anti-HCV antibodies, 93.6% of them had a positive result and in 70.5% was determined HCV active infection. High frequency of subtype 1a (46.2%), followed by an equal proportion of subtypes 3a, 4a, and 4d (15.4%) was obtained. Two potential recombinants, RF1_2k/1b (3.8%) and 2q/2k (3.8%) were identified. Substitutions V36L/P, T54A, I72L/N/T/V, Q80K/G, S122R/T, D168Q, and I170L/V were observed in 65.4% of the samples. The T54A and Q80K mutations, and the combination V36L + T54A were also identified. Polymorphisms were observed exclusively associated with specific genotypes, particularly, I72L and D168Q with genotype 3, and S122T with genotype 4. The V36L substitution was identified in 92.8% of sequences of non-genotype 1 denoting that this amino acid substitution is a natural polymorphism associated with non-genotype 1 strains. Although no major PI resistance mutations were detected, a more extensive study is needed to evaluate the impact of mutations identified in efficacy of PI treatment.
Department of Infectious Diseases, National Reference Laboratory of HIV and Hepatitis B and C, National Institute of Health, Lisbon, Portugal.
Tânia
T
Silva
Department of Infectious Diseases, National Reference Laboratory of HIV and Hepatitis B and C, National Institute of Health, Lisbon, Portugal.
Helena
H
Cortes Martins
Support office for Drug Addicts, Association of Ares do Pinhal, Lisboa, Portugal.
Rodrigo
R
Coutinho
Support office for Drug Addicts, Association of Ares do Pinhal, Lisboa, Portugal.
Emília
E
Leitão
Support office for Drug Addicts, Association of Ares do Pinhal, Lisboa, Portugal.
Rui
R
Silva
Department of Infectious Diseases, National Reference Laboratory of HIV and Hepatitis B and C, National Institute of Health, Lisbon, Portugal.
Elizabeth
E
Pádua
D019943:Amino Acid Substitution / Q000187:drug effects; D000998:Antiviral Agents / Q000009:adverse effects / Q000494:pharmacology / Q000627:therapeutic use; D001483:Base Sequence; D060085:Coinfection; D024882:Drug Resistance, Viral / Q000235:genetics; D055030:Drug Users; D005838:Genotype; D015658:HIV Infections / Q000150:complications* / Q000188:drug therapy / Q000821:virology; D016174:Hepacivirus / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D006526:Hepatitis C / Q000150:complications / Q000188:drug therapy / Q000821:virology*; D006801:Humans; D020125:Mutation, Missense; D011110:Polymorphism, Genetic; D011480:Protease Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D017422:Sequence Analysis, DNA; D017361:Viral Nonstructural Proteins / Q000235:genetics; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D000998:Antiviral Agents; D011480:Protease Inhibitors; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
HCV/HIV co-infection; Hepatitis C virus; NS3 region sub-typing; drug-naive to protease inhibitors; injecting drug users; resistance mutations