Sequence elements correlating with circulating viral load in genotype 1b hepatitis C virus infection.

Area of Science:

• Virology
• Genetics
• Hepatology

Background:

• Hepatitis C virus (HCV) infection is a major global health concern.
• Understanding factors influencing HCV viral load is crucial for effective treatment strategies.
• Genomic variations within HCV can impact viral replication and pathogenesis.

Purpose of the Study:

• To investigate the correlation between HCV genomic sequences and circulating HCV RNA levels.
• To identify specific genetic elements that influence viral load.
• To explore the role of the interferon sensitivity-determining region (ISDR) and other viral residues in determining serum HCV RNA load.

Main Methods:

• Correlational analysis of HCV genomic sequences and serum HCV RNA levels in 226 patients.
• Whole genome sequencing of HCV from patients with high and low viral loads.
• Amino acid sequence analysis of candidate residues and flanking regions in 67 additional patients.

Main Results:

• A strong correlation was observed between the ISDR sequence and serum viral load.
• Several candidate residues associated with viral load were identified through whole genome analysis.
• Amino acid residue 962 showed significant variation between patients with low and high viral loads (P=0.042).
• Alanine at residue 962 was more frequent in patients with high viral loads.

Conclusions:

• Serum HCV RNA loads are inversely correlated with amino acid substitutions in the ISDR.
• Amino acid residue 962 is identified as a potential second determinant of serum HCV RNA load.
• These findings contribute to understanding HCV genetic determinants of viral load and may inform therapeutic approaches.