HCV Genotype 1 Subtypes (1a and 1b): Similarities and Differences in Clinical Features and Therapeutic Outcome

Hepatol Int. 2015 Jan;9(1):52-7. doi: 10.1007/s12072-014-9556-2. Epub 2014 Aug 13.

Abstract

Aim: To evaluate similarities and differences in HCV-1 subtypes 1a and 1b in the presenting clinical features and the response to peg-interferon and ribavirin (Peg/RIBA).

Patients and methods: A total of 1,233 naïve patients with HCV genotype-1 infection, 159 (13%) with subtype 1a and 1,074 (87%) with subtype 1b were treated with Peg-IFN/RIBA at 12 Italian centers. Covariates included in the logistic model were age, gender, BMI, serum alanine aminotransferase, serum gamma-glutamiltranspeptidase (γGT), platelets counts, liver fibrosis, the occurrence of type 2 diabetes, baseline viremia, and IL28B genotype.

Results: At multivariate analysis, baseline characteristics differentiating patients with HCV-1a versus HCV-1b were young age, male gender, no F4 fibrosis, and no diabetes. SVR was achieved by 37% of patients with subtype 1b and 45% of those with subtype 1a, a nonsignificant difference of 8% (p = 0.069). In patients with subtype 1a, predictors of SVR were IL28B CC (OR 5.78, CI 1.98-16.83), RVR (OR 4.18, CI 1.66-10.55), female gender (OR 2.83, CI 1.83-6.78), and HCVRNA (OR 0.55, CI 0.32-0.96). In patients with subtype 1b, the ranking of predictors was levels RVR (OR 6.49, CI 4.32-9.73), IL28B CC (OR 3.32, CI 2.15-4.58), γGT (OR 1.59, CI 0.14-2.22), HCVRNA (OR 0.61, CI 0.47-0.79), and age (OR 0.01, CI 0.02-0.42).

Conclusion: In Italy HCV-1 subtype 1a prevails in young male patients with less advanced liver damage, findings that imply a more recent spreading of the infection with this viral strain. The two HCV-1 subtypes appear equally responsive to Peg-IFN/RIBA, with IL28B genotyping and monitoring of RVR mostly influencing the therapeutic response.

MeSH terms

  • Adult
  • Age Factors
  • Antiviral Agents / therapeutic use*
  • Diabetes Mellitus, Type 2 / complications
  • Female
  • Genotype
  • Hepacivirus / genetics*
  • Hepatitis C, Chronic / complications
  • Hepatitis C, Chronic / drug therapy*
  • Humans
  • Interferon alpha-2
  • Interferon-alpha / therapeutic use
  • Interferons
  • Interleukins / blood
  • Interleukins / genetics*
  • Liver Cirrhosis / virology
  • Male
  • Middle Aged
  • Polyethylene Glycols / therapeutic use
  • RNA, Viral / blood*
  • Recombinant Proteins / therapeutic use
  • Ribavirin / therapeutic use
  • Sex Factors
  • Treatment Outcome

Substances

  • Antiviral Agents
  • IFNL3 protein, human
  • Interferon alpha-2
  • Interferon-alpha
  • Interleukins
  • RNA, Viral
  • Recombinant Proteins
  • Polyethylene Glycols
  • Ribavirin
  • Interferons
  • peginterferon alfa-2b
  • peginterferon alfa-2a