Role of IL28B genotyping in patients with hepatitis C virus-associated mixed cryoglobulinemia and response to PEG-IFN and ribavirin treatment

Genetic Association of Hepatitis C-Related Mixed Cryoglobulinemia: A 10-Year Prospective Study of Asians Treated with Antivirals

Genetic profiles of hepatitis C virus (HCV)-associated mixed cryoglobulinemia (MC) in Asians remain elusive. A 10-year prospective cohort study was conducted with 1043 consecutive HCV Ab-positive Taiwanese surveyed with 13 single nucleotide polymorphisms (SNPs). Of 1043, 589 (56.5%) had baseline MC, 934 (89.5%) had positive HCV RNA, 796 completed anti-HCV therapy, and 715 had sustained virological responses (SVRs). SNP associations were surveyed withgenotypic, allelic, trend, permutation and multivariate analyses. At baseline, higher male sex and MC rates were noted in HCV RNA-positive than RNA-negative patients; higher female sex and positive HCV RNA rates but lower HCV RNA levels were noted in patients with than those without MC. Baseline associations were: HLA II-rs9461776 A allele, IFNL3-rs12979860 T allele, SERPINE1-rs6976053 C allele and MC with HCV RNA positivity; IFNL3-rs12979860 C allele, ARNTL-rs6486122 T allele and HCV RNA positivity with baseline MC. In SVR patients, RETN-rs1423096 C allele and SERPINE1-rs6976053 T allele were associated with 24-week and 10-year post-therapy MC, respectively. Conclusions: HCV RNA, IFNL3-rs12979860 and ARNTL-rs6486122 were associated with baseline MC; RETN-rs1423096 and SERPINE1-rs6976053 were associated with short- and long-term post-therapy MC in SVR patients, respectively. Links with HCV RNA and immune-associated SNPs suggest MC an immune reaction to expel HCV.

Role of ribavirin in the treatment of hepatitis C virus-associated mixed cryoglobulinemia with interferon-free regimens

Mixed cryoglobulinemia (MC) is the most common extrahepatic manifestation of chronic hepatitis C (CHC), with the presence of symptoms in 10-15% of cases. There have been encouraging data regarding immunological and clinical responses in patients treated with the novel combinations of direct-acting antivirals (DAAs), but the role of ribavirin (RBV) in the treatment of MC has not yet been demonstrated. We prospectively enrolled 132 patients affected by MC and CHC, and virological, immunological and clinical responses were evaluated at 12 weeks after completion of treatment. All subjects were treated with interferon (IFN)-free regimens according to clinical guidelines, with or without RBV. All patients achieved a virological response. A complete immunological response (CR) was observed in 71 subjects (53.8%), a partial response in 44 (33.3%), and no response in 17 (12.8%). Ten patients showed a complete resolution of symptoms (7.6%), and 31 showed a significant improvement (23.5%). CR was significantly higher in patients taking RBV (71.1 vs. 44.8%, p < 0.001) and in treatment-naïve patients (62.5 vs. 43.3%, p < 0.001). In logistic regression analysis, duration of HCV infection of less than 20 years (OR 2.448; 95% IC 1.335-6.202; p = 0.019), treatment-naïve status (OR 2.885; 95% IC 1.404-9.660; p = 0.025) and the use of RBV (OR 6.961; 95% IC 3.912-26.885; p < 0.001) were predictors of CR. In MC patients, IFN-free regimens are effective and well tolerated, and RBV seems to significantly increase the immunological response and promote a decline in cryocrit.

Pharmacogenetic analysis of hepatitis C virus related mixed cryoglobulinemia

AIM

Mixed cryoglobulinemia (MC) is an extra hepatic hepatitis C virus related problem and different studies suggested genetics' role in predicting this complication. We evaluated the influence of SNPs in IL-28B, SLC29A1, SLC28A2, NT5C2, HNF4 and ABCB1 genes in MC prediction.

PATIENTS & METHODS

SNPs were evaluated through real-time PCR.

RESULTS

 ABCB1 (gene encoding P-glycoprotein) 3435C>T SNP was associated with MC presence (p = 0.034): related to T allele carriers (CC vs CT/TT), we reached a p-value of 0.013. In the logistic regression analysis baseline viral load >600.000 IU/ml (p < 001), IL28B rs8099917/rs12979860 TT/CC (p < 0.001), NT5 (gene encoding for 5' nucleotidase) 153 TC (p = 0.012) and ABCB1 3435 CT/TT (p = 0.034) genotypes predicted MC presence.

CONCLUSION

These data could help clinicians to identify patients with higher probability to show MC extra hepatic complication.

Vitamin D pathway gene polymorphisms as predictors of hepatitis C virus-related mixed cryoglobulinemia

Mixed cryoglobulinemia (MC) is the most frequent extrahepatic hepatitis C virus (HCV) complication. Vitamin D is a modulator of several biological processes, including immune and skeletal systems and MC presence and systemic vasculitis were associated independently with low levels of vitamin D. Considering the impact of vitamin D, we aimed to evaluate the role of some single nucleotide polymorphisms (SNPs) of vitamin D pathway genes in the prediction of MC in HCV patients treated with pegylated interferon and ribavirin. We investigated SNPs in IL-28B, CYP27B1, CYP27A1, CYP24A1, VDBP, and VDR genes through real-time PCR. VDR gene SNPs were related to baseline viral load: VDR BsmI AA (P=0.018), TaqI CC (P=0.009), and ApaI AA (P=0.004) showed a lower baseline HCV count. Among vitamin D pathway gene polymorphisms, VDR FokI T>C was a factor associated with the presence of MC in the study population (P=0.011): related to C allele carriers (TT vs. TC/CC), we obtained a P-value of 0.003. In the logistic regression analysis to assess which demographic, clinical, or genetic factors could predict the presence of cryoglobulin, the TT/CC IL-28B rs8099917/rs12979860 haplotype [P<0.001; odds ratio (OR) 3.516 (1.951-6.336)], baseline viral load [P<0.001; OR 1.000 (0.999-1.001)], and VDR FokI TC/CC genotypes [0.044; OR 0.463 (0.218-0.981)] remained in the final regression model. These data could help physicians identify patients with a higher probability of developing MC extrahepatic complications.

Pharmacogenetics of ribavirin-induced anemia in HCV patients

Dual therapy (pegylated interferon plus ribavirin) was considered the standard of care for hepatitis C virus (HCV) treatment until 2011, when the first-wave direct-acting antivirals were added to this regimen for HCV genotype-1 patients to increase the sustained virological response rate. The second-wave direct-acting antivirals entered the clinical use also in some ribavirin (RBV)- and/or interferon-free combinations. Nevertheless, since some of the new therapeutic regimens also include RBV and its use results still associated with hemolytic anemia, this requires countermeasures to be prevented. These include the identification of several host predictive factors involved in RBV absorption, distribution, metabolism, elimination and many others that might influence this toxic effect. For this reason, we provided an overview of the potential role of pharmacogenomics in predisposing RBV-treated HCV patients to anemia.

Association of IL28B rs8099917 genotype and female sex with spontaneous clearance of hepatitis C virus infection: a Japanese cross-sectional study

Hepatitis C virus (HCV) infection is a serious global health problem. Previous studies have suggested that the interleukin 28B (IL28B) rs8099917 genotype is related to spontaneous clearance of HCV in Caucasian populations. Our objective was to investigate the association of the IL28B rs8099917 genotype with spontaneous clearance of HCV by community-dwelling Japanese. A cross-sectional community-based population study of 993 Japanese residents was conducted. Based on anti-HCV antibody and HCV RNA levels, 50 subjects were assigned to the spontaneous-clearance group, 155 to the chronic-infection group, and 788 to the control group. Logistic regression analysis was done to examine the roles of the IL28B rs8099917 genotype and sex. To analyze the interactions between these factors, an "IL28B rs809991 genotype × sex" interaction term was included in the multivariate analysis. Significantly more subjects in the spontaneous-clearance group than in the chronic-infection group had the favorable IL28B rs8099917 genotype and were female. Multivariate logistic regression analysis extracted the favorable IL28B rs8099917 TT genotype (odds ratio [OR] 9.39; 95% confidence interval [CI], 2.16-40.83, P = 0.003) and female sex (OR, 2.27; 95% CI, 1.16-4.45, P = 0.017) as factors contributing to the spontaneous clearance of HCV. No significant interaction was found between the IL28B rs8099917 genotype and sex (P for interaction = 0.428). Both the favorable IL28B rs8099917 genotype and female sex were associated with the spontaneous clearance of HCV in this Japanese population.