Low-density lipoprotein receptor genotyping enhances the predictive value of IL28B genotype in HIV/hepatitis C virus-coinfected patients.

Objective: The aims of this study were to appraise the predictive value of variations in a single-nucleotide polymorphism (SNP) in the low-density lipoprotein receptor (LDLR) gene for sustained virological response (SVR) to pegylated interferon (Peg-IFN) and ribavirin (RBV), as well as to analyze the relationship between LDLR genotype and other predictors of SVR, particularly IL28B genotype, in patients coinfected with HIV and hepatitis C virus (HCV).

Methods: One hundred and eighty-four HIV/HCV-coinfected, treatment-naive patients with chronic HCV infection, who received Peg-IFN and RBV, were included. Variations in the SNP rs14158 and rs12979860 were tested by Taqman PCR assay.

Results: Twenty-eight (38%) patients with rs14158 TT/TC and 61 (55%) with CC (P = 0.028) achieved SVR. The rates of SVR in patients with rs14158 TT/TC and with CC harboring HCV 1-4 were 20 and 41% (P = 0.020), respectively, and, in those with HCV genotype 2-3, 75 and 84% (P = 0.513), respectively. Patients with rs14158 CC showed less commonly plasma HCV-RNA load at least 600000 IU/ml (57 vs. 71%, P = 0.047) and lower likelihood of relapse (13 vs. 30%, P = 0.023). In patients with HCV genotype 1-4, the rates of SVR according to the combination of IL28B/LDLR genotypes were: CC/CC = 69%; CC/non-CC: 30%; non-CC/CC: 25%; non-CC/non-CC: 14% (P < 0.001).

Conclusion: Variations in rs14158 are associated with SVR to Peg-IFN and RBV in HIV/HCV-coinfected patients harboring HCV genotype 1-4. LDLR and IL28B genotypes seem to have a synergistic effect on SVR. The combined use of LDLR and IL28B genotypes in routine clinical practice could enhance the predictive value of IL28B genotype alone.