In patients with a sustained virological response (SVR; n = 455), at 24 weeks post-therapy, sex, BMI, aspartate aminotransferase to platelet ratio index (APRI), HOMA-IR and steatosis were associated with adiponectin levels, and IFNL3 genotype was associated with HOMA-IR levels.
Variants of TM6SF2 (30.9% vs. 25%, P = 0.40), IL28B and PNPLA3 were not directly associated with fibrosis severity, although variants of IL28B and PNPLA3 promoted steatosis (OR 1.36, 95% CI 1.06-1.75, P = 0.01) that in turn is associated with severe fibrosis.
Interleukin-28B (IL28B) and patatin-like phospholipase domain containing 3 (PNPLA3) gene polymorphisms are associated with hepatitis C virus (HCV) clearance and fatty liver, respectively.
PNPLA3 allele-G was associated with steatosis in patients with IL28B-CT/TT [57.7% (82/142) vs. 37.1% (56/151)] (p = 0.0001), but did not in IL28B-CC [47.8% (43/90) vs. 42% (37/88)] (p = 0.442).
Recent reports have suggested that PNPLA3, IL28B and TLR4-associated single nucleotide polymorphisms (SNPs) may have an impact on hepatic steatosis or fibrosis in patients with chronic HCV infection.
Additionally the presence of the otherwise favorable IL28B genetic variants in the context of HCV genotype 3 infection reportedly entail more pronounced liver fibrosis and steatosis.
IL28B and PNPLA3 are associated with hepatic steatosis prevalence and severity in Caucasians with G1 HCV, suggesting differing potential genetic risk pathways to steatosis.
A sustained virological response (SVR) was significantly associated with IL28B polymorphism (CC vs TT allele: odds ratio (OR), 25; CC vs CT allele: OR, 5.4), inflammation activity (G < 1 vs G > 1: OR, 3.9), fibrosis (F < 1 vs F > 1: OR, 5.9), platelet count (> 200 × 10(9)/L vs < 200 × 10(9)/L: OR, 4.7; OR in patients with genotype CT: 12.8), fatty liver (absence vs presence of steatosis: OR, 4.8), insulin resistance index (< 2.5 vs > 2.5: OR, 3.9), and baseline HCV viral load (< 10(6) IU/mL vs > 10(6) IU/mL: OR, 3.0).
After adjustment for age, viral load, IL28B CC genotype, treatment dose, and steatosis, p.148M/M remained a predictor of SVR in G1/4 patients with advanced fibrosis (OR 0.23, 95% CI 0.04-0.87).
The risk of steatosis was increased by carriage of I148M in PNPLA3, but only in patients with HCV genotypes non-3 (odds ratio [OR]=1.9, 95% confidence interval [CI]=1.6-2.3, p<0.001) and similar, albeit weaker associations were found for SNPs in peroxisome proliferator-activated receptor-γ (PPARG) and interleukin-28B (IL28B).
IL28B CC genotype is associated with less pronounced disturbances of lipid metabolism, as reflected both in serum lipoprotein levels and hepatic steatosis, in HCV infection.