Serum level of IP-10 increases predictive value of IL28B polymorphisms for spontaneous clearance of acute HCV infection

BACKGROUND & AIMS: Single nucleotide polymorphisms (SNPs) in IL28B and serum levels of interferon γ inducible protein 10 (IP-10) predict outcomes of antiviral therapy in patients with chronic hepatitis C. We associated IL28B SNPs rs12979860 and rs8099917, along with serum levels of IP-10, with outcomes of patients with acute hepatitis C (AHC).

METHODS: We studied 120 patients with AHC (64 male; 37 ± 16 years old) and 96 healthy individuals (controls). The IL28B SNPs rs12979860 and rs8099917 were detected using real-time polymerase chain reaction; serum concentrations of IP-10 were measured by enzyme-linked immunosorbent assays of 62 patients with AHC.

RESULTS: Hepatitis C virus was cleared spontaneously from 59 patients (49.2%). The IL28B rs12979860 C/C genotype was more frequent among patients with AHC than controls (62.5% vs 39.6%; P < .001) and among patients with spontaneous clearance than those without (74.6% vs 51.7%; P = .02) (positive predictive value, 60.3%). Patients with IL28B rs12979860 C/C more frequently developed jaundice (53.2% vs 27.6%; P = .022) than carriers of the T allele. The median level of IP-10 was lower among patients with AHC and spontaneous clearance (764 [113-2470] pg/mL) than those without spontaneous clearance (1481 [141-4412] pg/mL; P = .006). Based on receiver operating characteristic analysis, 540 pg/mL IP-10 was set as the cutoff for patients most likely to have spontaneous clearance (positive predictive value, 71.4%; negative predictive value, 65.9%). Including data on IP-10 levels increased the ability of the IL28B rs12979860 C/C to identify patients most likely to have spontaneous clearance (83% of those who had an IP-10 level <540 pg/mL and 32% who had an IP-10 level >540 pg/mL) (P < .01).

CONCLUSIONS: The combination of serum level of IP-10 and SNPs in IL28B can identify patients with AHC who are most likely to undergo spontaneous clearance and those in need of early antiviral therapy.