Identification of improved IL28B SNPs and haplotypes for prediction of drug response in treatment of hepatitis C using massively parallel sequencing in a cross-sectional European cohort

BACKGROUND: The hepatitis C virus (HCV) infects nearly 3% of the World's population, causing severe liver disease in many. Standard of care therapy is currently pegylated interferon alpha and ribavirin (PegIFN/R), which is effective in less than half of those infected with the most common viral genotype. Two IL28B single nucleotide polymorphisms (SNPs), rs8099917 and rs12979860, predict response to (PegIFN/R) therapy in treatment of HCV infection. These SNPs were identified in genome wide analyses using Illumina genotyping chips. In people of European ancestry, there are 6 common (more than 1%) haplotypes for IL28B, one tagged by the rs8099917 minor allele, four tagged by rs12979860. METHODS: We used massively parallel sequencing of the IL28B and IL28A gene regions generated by polymerase chain reaction (PCR) from pooled DNA samples from 100 responders and 99 non-responders to therapy, to identify common variants. Variants that had high odds ratios and were validated were then genotyped in a cohort of 905 responders and non-responders. Their predictive power was assessed, alone and in combination with HLA-C. RESULTS: Only SNPs in the IL28B linkage disequilibrium block predicted drug response. Eighteen SNPs were identified with evidence for association with drug response, and with a high degree of confidence in the sequence call. We found that two SNPs, rs4803221 (homozygote minor allele positive predictive value (PPV) of 77%) and rs7248668 (PPV 78%), predicted failure to respond better than the current best, rs8099917 (PPV 73%) and rs12979860 (PPV 68%) in this cross-sectional cohort. The best SNPs tagged a single common haplotype, haplotype 2. Genotypes predicted lack of response better than alleles. However, combination of IL28B haplotype 2 carrier status with the HLA-C C2C2 genotype, which has previously been reported to improve prediction in combination with IL28B, provides the highest PPV (80%). The haplotypes present alternative putative transcription factor binding and methylation sites. CONCLUSIONS: Massively parallel sequencing allowed identification and comparison of the best common SNPs for identifying treatment failure in therapy for HCV. SNPs tagging a single haplotype have the highest PPV, especially in combination with HLA-C. The functional basis for the association may be due to altered regulation of the gene. These approaches have utility in improving diagnostic testing and identifying causal haplotypes or SNPs

High Rates of Hepatitis C Virus Reinfection and Spontaneous Clearance of Reinfection in People Who Inject Drugs: A Prospective Cohort Study

Hepatitis C virus reinfection and spontaneous clearance of reinfection were examined in a highly characterisedcohort of 188 people who inject drugs over a five-year period. Nine confirmed reinfections and 17 possiblereinfections were identified (confirmed reinfections were those genetically distinct from the previous infection andpossible reinfections were used to define instances where genetic differences between infections could not beassessed due to lack of availability of hepatitis C virus sequence data). The incidence of confirmed reinfection was28.8 per 100 person-years (PY), 95%CI: 15.0-55.4; the combined incidence of confirmed and possible reinfectionwas 24.6 per 100 PY (95%CI: 16.8-36.1). The hazard of hepatitis C reinfection was approximately double that ofprimary hepatitis C infection; it did not reach statistical significance in confirmed reinfections alone (hazard ratio [HR]:2.45, 95%CI: 0.87-6.86, p=0.089), but did in confirmed and possible hepatitis C reinfections combined (HR: 1.93,95%CI: 1.01-3.69, p=0.047) and after adjustment for the number of recent injecting partners and duration of injecting.In multivariable analysis, shorter duration of injection (HR: 0.91; 95%CI: 0.83-0.98; p=0.019) and multiple recentinjecting partners (HR: 3.12; 95%CI: 1.08-9.00, p=0.035) were independent predictors of possible and confirmedreinfection. Time to spontaneous clearance was shorter in confirmed reinfection (HR: 5.34, 95%CI: 1.67-17.03,p=0.005) and confirmed and possible reinfection (HR: 3.10, 95%CI: 1.10-8.76, p-value=0.033) than primary infection.Nonetheless, 50% of confirmed reinfections and 41% of confirmed or possible reinfections did not spontaneouslyclear.Conclusions: Hepatitis C reinfection and spontaneous clearance of hepatitis C reinfection were observed at highrates, suggesting partial acquired natural immunity to hepatitis C virus. Public health campaigns about the risks ofhepatitis C reinfection are required

IL28B, HLA-C, and KIR Variants Additively Predict Response to Therapy in Chronic Hepatitis C Virus Infection in a European Cohort: A Cross-Sectional Study

Vijayaprakash Suppiah and colleagues show that genotyping hepatitis C patients for the IL28B, HLA-C, and KIR genes improves the ability to predict whether or not patients will respond to antiviral treatment

Genetics of autoimmune diseases : a study of immuno-regulatory genes : CTLA4, IL-4, IL-4RA, SOCS3, IFNG and IL-26 in multiple sclerosis, rheumatoid arthritis and juvenile idiopathic arthritis

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Pharmacogenomics of interferon beta and glatiramer acetate response : a review of the literature

Multiple sclerosis (MS) is one of the most common inflammatory and degenerative autoimmune diseases of the central nervous system with considerable heterogeneity in all aspects, including response to therapy. A number of disease modifying drugs, including traditional first line agents such as, interferon-beta (IFN-β) and glatiramer acetate (GA) are available for disease management. However, a considerable number of patients fail to achieve adequate response at therapeutic doses of IFN-β or GA. This variability in response to treatment has prompted the search for prognostic markers in order to personalize and optimize therapy so as to treat MS more efficiently. This review will summarize the existing literature examining the pharmacogenomics of IFN-β and GA response in MS patients.

Changes in diapause related gene expression pattern during early embryonic development in HCl-treated eggs of bivoltine silkworm Bombyx mori (Lepidoptera: Bombycidae)

Investigation of differential expression of diapause related genes (five metabolic, five heat shock protein and one translational regulatory) in HCl-treated (non-diapause) and untreated (diapause) eggs of B. mori during early embryogenesis (up to 48h following oviposition) revealed the up-regulation of sorbitol dehydrogenase upon HCl treatment, indicating increased glycogen synthesis for further embryonic development but, down-regulation of phosphofructo kinase gene expression after 18h of oviposition indicating an arrest of glycerol and sorbitol conversion. The expression of poly A binding protein gene expression was higher upon HCl treatment, revealing the initiation of translation. The expression levels of other genes analyzed did not vary significantly, except for Hsp90 and Hsp40, which were up-regulated on acid treatment until 18h. Thus, Sorbitoldehydrogenase and phosphofructo kinasegenes have a crucial role in diapause termination as evidenced by HCl treatment, while the other genes did not have major roles