There are less data concerning the role of IL28B in other HCV genotypes. learn more The IL28B polymorphism appears to be relevant to peg-IFN therapy for genotype 4 (G4) HCV,6,31 with a similar effect size to that observed in the setting of G1 HCV. In a recent small study of peg-IFN and RBV treatment in genotype 6 (G6) HCV patients of Chinese ancestry, 23 of
24 carried the good-response genotype for rs12979860. All attained an SVR. Only one patient carried a poor-response genotype, and this patient relapsed after 48 weeks of treatment.32 The relationship between the IL28B genotype and treatment response in G6 HCV is therefore not clear. IL28B genotyping is less relevant to the treatment of G2/3 HCV, and for now, it should not be performed routinely, but rather reserved for research protocols. It will be particularly important to investigate the relevance of the IL28B genotype selleck products in
G3 patients with other unfavorable IFN-response characteristics, especially cirrhosis and non-RVR, where the IL28B genotype might be relevant to the decision to extend therapy from 24 to 48 weeks. This should be prospectively evaluated. For G4 HCV, the IL28B polymorphism appears to have a similar clinical utility to G1 HCV. The association between peg-IFN and RBV treatment response and the IL28B genotype in HCV mono-infected patients has been replicated in the setting of HIV/HCV co-infection. In a retrospective candidate gene study of Spanish patients with HIV/HCV co-infection, the good-response IL28B genotype was associated with higher rates of SVR compared to poor-response variants (rs12979860, 75% vs 38% SVR rate, respectively, P < 0.0001).31 The IL28B polymorphism remained a significant independent predictor,
even after adjusting for other important clinical factors, such as HCV genotype, HCV—RNA concentration, the absence of fibrosis,31 and serum low-density lipoprotein level.33 Similar findings have been reported in other HIV/HCV co-infected cohorts.34–36IL28B variation is associated with improved phase I kinetics, as is seen during treatment MCE公司 of HCV mono-infected patients.37,38 The strength of the association also varies according to HCV genotype, where a strong effect is seen in G1/4 HCV, but the effect is much weaker in G2/3 HCV. HIV co-infection does not appear to modulate the association between the IL28B polymorphism and spontaneous clearance, with similar OR for spontaneous clearance compared to HCV mono-infected individuals.6,9 Although very relevant to HCV outcomes in HIV/HCV co-infection, the IL28B genotype appears to have no impact on HIV outcomes.39,40 The clinical course of HCV post-transplantation is frequently aggressive.