The predictive value of IL28B rs12979860, rs11881222 and rs8099917 polymorphisms and IP-10 in the therapeutic response of Egyptian genotype 4 patients.

UNLABELLED: Interleukin-28B (IL28B) polymorphisms have previously been reported to be strongly associated with spontaneous and treatment-induced HCV viral clearance. AIM: To assess the impact of four different IL28B polymorphisms and their haplotype combination and interferon-c inducible protein 10 (IP-10) in response to treatment in Egyptian genotype 4 patients. METHOD: 159 HCV-genotype 4 patients were included. All patients were treated with Peginterferon alph2a/Ribavirin for 48 wk. The following polymorphisms rs12979860, rs11881222, rs8103142 and rs8099917 and rs80803142 of Il-28 were known to be associated with the sustained virological response. They were genotyped using the TaqMan assay. IP-10 was assessed by Eliza. RESULTS: The data indicated that all SNPs are within the Hardy-Weinberg Equilibrium (HWE) except for rs8103142 (p=6.255(-9)), therefore it was excluded from the study since it deviates from HWE-P. The CC, AA and TT genotypes of rs12979860, rs11881222 and rs8099917 were the more frequent genotypes among the responders at RVR, EVR, ETR and SVR, respectively. The frequency of CC, CT, and TT genotype was 46.4%, 38.1% and 15.5% among responders of RVR, and was 46.9%, 45.9% and 7.2 among responders of SVR for rs12979860, respectively. The relapse rate was 18.0% and 16.0 % during EVR and ETR, while the response rate was 52.8%, 58.5%, 59.7% and 61.6% after 4, 12, 48 and 72 weeks of treatment. The transient virological response (TVR) was 6.9% among HCV patients. The results showed that the odds ratio and 95% CI of HCV genotype 4 patients to have a better sustained response to treatment (SVR) was 2.92, (1.83-4.68, p=2.01(-5)), 2.89 (1.79-4.70, p=2.53(-5)), and 2.73 (0.21-0.65, p=0.0007) for those with the major allele "C" of rs12979860, the "A" allele of rs11881222, and the "T" allele of rs8099917, respectively. Furthermore, the positive predictive value (PPV) of the major homozygous alleles for SVR with better response to therapy was in the following order: 78.69%, 68.42%, and 32.14% with a positive likelihood ratio of 1.95, 1.25, and 0.86 for rs12979860, rs11881222 and rs8099917, respectively. The haplotype formed between the 3 studied SNPs (rs12979860, rs11881222 and rs8099917) showed that two haplotypes (TGG and TGT) increased the probability of a poor response to therapy, but the CAT haplotype had the opposite effect. Multinomial logistic regression analysis revealed that the viral load and rs12979860 are the only significant actors involved in the efficacy of the treatment response among the cohort study. In addition, patients with SVR had significantly lower values of IP-10 than non-responder patients (NR), with a P-value<=0.001. CONCLUSIONS: In genotype 4 cases, the IL28B SNPs rs12979860 rs8099917, and rs11881222 are the strongest predictors of a response, while IP-10 is a strong negative biomarker of a response. Accounting for this factor is important in the individualization of treatment and enhances the degree of predictiveness of the IL28 polymorphism in the final treatment outcome. The frequent distribution of C, A and T alleles of IL28 polymorphism are higher among TVR, which may reflect sensitivity to prolonged course.

Interleukin-28 and hepatitis C virus genotype-4: treatment-induced clearance and liver fibrosis.

AIM: To investigate the association between interleukin-28B (IL28B) genotype and response to treatment and hepatic fibrosis in patients with hepatitis C virus (HCV) genotype 4. METHODS: Two hundred and one HCV-genotype 4 patients were included. All patients were treated with Peginterferon alph2a/Ribavirin for 48 wk. End of treatment response (ETR) was defined as loss of detectable serum HCV RNA at the end of treatment. Sustained viral response (SVR) was defined as loss of detectable serum HCV RNA at the end of 24 wk follow up. Genotyping of IL28B rs12979860 was performed using the TaqMan assay. We used logistic regression to estimate the adjusted odds ratio (aOR) and 95%CI. RESULTS: The study included 201 HCV-genotype 4 patients. The majority of patients were men (89.6%), with a median age of 47 years, inter-quartile range (40-51). Approximately 62.5% of patients had ETR, and 49.6% had SVR. Individuals who achieved SVR were more likely to be younger (χ(2) = 4.91, P = 0.027), and less likely to have fibrosis (χ(2) = 15.54, P < 0.0001), or inflammation (χ(2) = 7.58, P = 0.006). The genotype distribution of rs12979860 was 36.2%, 49.0% and 14.8% for genotypes CC, CT, and TT, respectively. In these participants, rs12979860 genotype distribution did not differ by gender (P = 0.466), pretreatment viral load (P = 0.600), inflammation (P = 0.435), or fibrosis (P = 0.291). The frequencies of IL28B rs12979860 genotypes were TT (14.8%), CT (49.0%), and CC (36.2%). Compared to rs12979860 genotype TT, aORs (95%CI) for ETR and SVR were: CC genotype, [17.55 (5.34-57.69) and 5.92 (2.09-16.76), respectively]; CT genotype, [5.15 (1.80-14.78) and 2.48 (0.94-6.52), respectively]. In the current study, the patients who did not achieve ETR or SVR had a lower prevalence of rs12979860 CC (17.4% and 23.3%, respectively) than individuals who had ETR or SVR (47.9% and 47.2%, respectively). Individuals with rs12979860 CC genotype had approximately 6 times the odds of SVR compared to individuals with TT genotype (aOR = 5.92; 95%CI: 2.09-16.76). Similarly, patients with CT genotype had SVR more often than patients with TT genotype (aOR = 2.48; 95%CI: 0.94-6.52). Carrying at least one copy of the C allele (genotypes CT and CC) had almost 8 times the probability of ETR compared to those with genotype rs12979860 TT (aOR = 7.87; 95%CI: 2.84-21.82), and approximately 3 times the odds of SVR compared to those with genotype rs12979860 TT (aOR = 3.46; 95%CI: 1.37-8.74). In addition, data were consistent with a significant gene-dose relationship (aOR = 4.05/allele; 95%CI: 2.27-7.22). The association between rs12979860 genotype and SVR was similar among those who achieved and those who did not achieve SVR. CONCLUSION: In HCV-genotype 4 patients, rs12979860 is a sensitive predictor of viral clearance, independent of viral load, age, gender or fibrosis, with no similar relation to severity of fibrosis.