Interleukin 28B Genotyping Research Articles

Interleukin-28B polymorphism in hepatitis C and liver transplantation

The discovery of interleukin-28B (IL-28B) single-nucleotide polymorphisms has opened an important new area of research in liver transplantation (LT) for hepatitis C virus (HCV). Both recipient- and donor-derived IL-28B genotypes affect the post-LT treatment response, with sustained virological response (SVR) rates oscillating from >50% in homozygotes for the favorable allele (up to 90% when this is present in both the recipient and the donor) to <15% in homozygotes for the unfavorable allele and from 30% to 50% in heterozygotes. Other key posttransplant outcomes affected by the IL-28B genotype are the time to histological recurrence, HCV RNA and alanine aminotransferase levels, histological variables (including the rate of fibrosis progression), and hepatocellular carcinoma. Interactions between donor and recipient IL-28B genotypes are complex and may affect outcomes not directly related to HCV infections, such as acute cellular rejection (ACR) and metabolic diseases. A preferential allocation system in which livers from donors homozygous for the favorable allele are given to HCV patients might be postulated to improve SVR rates and post-LT outcomes in recipients with HCV infections (a 25% increase in SVR and an 8% decrease in mortality at 5 years). Although negative effects from this are difficult to predict, they could include an accelerated progression of fibrosis in patients with failed HCV eradication and an increase in ACR in non-HCV patients. Our knowledge of the precise role of IL-28B genotypes in the course of post-LT HCV is evolving, but existing knowledge suggests the possibility of exploring strategies that use IL-28B genotyping to reduce the impact of post-LT adverse outcomes.

Early viral load and recipient interleukin-28B rs12979860 genotype are predictors of the progression of hepatitis C after liver transplantation

There have been few detailed studies of viral kinetics after liver transplantation (LT), and conflicting data have been reported on viral loads and the severity of recurrent hepatitis C virus (HCV) disease. This long-term study aimed to examine (1) the impact of HCV RNA levels at specific points in time within the first year and (2) the influence of interleukin-28B (IL-28B) genotypes on patient outcomes and the severity of recurrent HCV disease. The viral loads were measured 2, 4, 12, 24, and 48 weeks after LT, and the recipient/donor IL-28B genotypes of 164 patients were determined. A Cox regression analysis showed that the viral load at week 2 was an independent negative predictor of recipient outcomes. A week 2 viral load ≥ 6.0 log(10) IU/mL was significantly associated with reduced patient survival. After a mean follow-up of 6.5 years, 21 of 164 patients (12.8%) developed a cholestatic type of HCV recurrence and/or rapidly progressed to cirrhosis within 1 year. A multivariate binary regression analysis showed that HCV viremia at week 2 and a non-C/C recipient IL-28B genotype were independent risk factors for cholestatic recurrent HCV. No predictive factors could be found for the occurrence of recurrent liver cirrhosis 5 and 10 years after LT. Our study shows that the HCV RNA level at week 2 and the recipient IL-28B genotype are independent, statistically significant risk factors for post-LT cholestatic HCV, and it emphasizes the importance of viral load monitoring and IL-28B genotyping for identifying HCV recipients at risk for severe HCV recurrence.

Will IL28B polymorphisms remain relevant to direct-acting antiviral treatment paradigms?

In the past 2 years the ability to successfully eradicate chronic HCV infection has been substantially enhanced by two landmark scientific breakthroughs. Firstly, the advent of HCV-specific direct-acting antiviral (DAA) compounds has resulted in a significant increase in sustained virological response rates in HCV genotype-1-infected treatment-naive patients and in non-responders to prior pegylated interferon and ribavirin therapy. Secondly, the identification of single nucleotide polymorphisms near the interleukin 28B (IL28B) gene that potently influence spontaneous and treatment-induced recovery from HCV infection has improved our understanding of hepatitis C pathogenesis, has helped spur the development of novel antiviral therapies and has provided a tool for pretreatment decision making in the context of genotype 1 HCV infection. In light of these advances, we review the interaction between these two discoveries and discuss the role of IL28B genotyping prior to treatment initiation in the context of both standard therapy and the newly approved DAA-based regimens. The role of IL28B genotyping is particularly relevant as DAAs are more expensive and carry a higher risk for anaemia and other drug-related side effects, while decision-making based on IL28B genotype may permit non-DAA-based treatment algorithms.

Interleukin-28B Genotyping by Melt-Mismatch Amplification Mutation Assay PCR Analysis Using Single Nucleotide Polymorphisms rs12979860 and rs8099917, a Useful Tool for Prediction of Therapy Response in Hepatitis C Patients

Several studies have identified associations between single nucleotide polymorphisms (SNPs) occurring near the interleukin-28B (IL-28B) gene and response to antiviral treatment among hepatitis C virus (HCV) patients. Here, we describe a reliable melt-mismatch amplification mutation assay (melt-MAMA) PCR-based genotyping method for IL-28B which can be used in the management of HCV patients, helping to better define the course of therapy.

Potential Role for Interleukin-28B Genotype in Treatment Decision-Making in Recent Hepatitis C Virus Infection

Polymorphisms in the IL28B (interleukin-28B) gene region are important in predicting outcome following therapy for chronic hepatitis C virus (HCV) infection. We evaluated the role of IL28B in spontaneous and treatment-induced clearance following recent HCV infection. The Australian Trial in Acute Hepatitis C (ATAHC) was a study of the natural history and treatment of recent HCV, as defined by positive anti-HCV antibody, preceded by either acute clinical HCV infection within the prior 12 months or seroconversion within the prior 24 months. Factors associated with spontaneous and treatment-induced HCV clearance, including variations in IL28B, were assessed. Among 163 participants, 132 were untreated (n = 52) or had persistent infection (infection duration ≥26 weeks) at treatment initiation (n = 80). Spontaneous clearance was observed in 23% (30 of 132 participants). In Cox proportional hazards analysis (without IL28B), HCV seroconversion illness with jaundice was the only factor predicting spontaneous clearance (adjusted hazards ratio = 2.86; 95% confidence interval = 1.24, 6.59; P = 0.014). Among participants with IL28B genotyping (n = 102 of 163 overall and 79 of 132 for the spontaneous clearance population), rs8099917 TT homozygosity (versus GT/GG) was the only factor independently predicting time to spontaneous clearance (adjusted hazard ratio = 3.78; 95% confidence interval = 1.04, 13.76; P = 0.044). Participants with seroconversion illness with jaundice were more frequently rs8099917 TT homozygotes than other (GG/GT) genotypes (32% versus 5%, P = 0.047). Among participants adherent to treatment and who had IL28B genotyping (n = 54), sustained virologic response was similar among TT homozygotes (18 of 29 participants, 62%) and those with GG/GT genotype (16 of 25, 64%, P = 0.884). During recent HCV infection, genetic variations in IL28B region were associated with spontaneous but not treatment-induced clearance. Early therapeutic intervention could be recommended for individuals with unfavorable IL28B genotypes.