Effect of Interleukin 28B SNP rs12979860 Genotype on Viral Load in Hepatitis C Virus in Kolar Population, Karnataka, India

Abstract

Introduction: The natural course of Hepatitis C Virus (HCV) infection is influenced by a number of host and viral variables. Interleukin 28B (IL28B) is a kind of interleukin. A Single Nucleotide Polymorphism (SNP) designated as rs12979860 was reported to predict viral clearance with and without treatment. Subjects with the GG (favourable) IL28B rs12979860 genotype were more likely to clear the infection spontaneously and respond well to therapy. These findings imply that people who have the “favourable” GG genotype have a lower viral burden than those who have the “unfavourable” AA genotype. Aim: To determine the effect of IL28B SNP rs12979860 genotype on HCV viral load in Kolar population, Karnataka, India. Materials and Methods: The present study was a case-control study which was carried out in Department of Microbiology, Sri Devaraj Urs Medical College, Kolar, Karnataka, India. Subjects were enrolled from Department of Medicine of R.L. Jalapa Hospital and Research Centre, teaching hospital of Sri Devaraj Urs Medical College between November 2020 to March 2021. A total of 248 patients were taken of which 124 were HCV antibody-positive and 124 were controls. The effect of IL28B rs12979860 SNP on HCV viral load and clearance among HCV-infected patients were examined. Detection and quantification of HCV-RNA was determined by Reverse Transcriptase Polymerase Chain Reaction (RT-PCR). IL28B rs12979860 genotyping was performed using PCR and Restriction Fragment Length Polymorphism (RFLP) technique and specific primers. Statistical analysis was done by using open Epi tool. The frequency, percentage and Chi-square test were used to analyse categorical variable. A p-value <0.05 was considered as significant. Results: In the present study, in group 1, the frequency of G/G genotype was considerably high 83 (67%) compared to G/A 17 (13.7%) and A/A 24 (19.3%) and in group 2, the frequency of G/G genotype 84 (67.7%), G/A genotype 34 (27.4%) and A/A genotype 6 (4.9%). There was a statistically significant difference in both the HCV infected and healthy controls groups (p=0.002). The average (±SEM) HCV viral load was 4.6±3.6×107, 9.4±7.7×107 and 5.5±5.2×107 IU/mL in patients with the IL28B rs12979860 GG, GA and AA respectively. Also there was a significance between the viral load and IL28B rs12979860 (p-value <0.05). Conclusion: Thus, present study results indicate that the IL28B rs12979860 genotype has an effect on viral load in untreated HCV patients. These findings highlight the importance of viral-host interactions in influencing the outcome of HCV infection.

Keywords

• infection
• polymorphism
• ribonucleic acid levels