Hepatology. 2013 Jun;57(6):2124-34
Grebely J, Feld JJ, Applegate T, Matthews GV, Hellard M, Sherker A, Petoumenos K, Zang G,  Shaw I, Yeung B, George J, Teutsch S, Kaldor JM, Cherepanov V, Bruneau J, Shoukry NH, Lloyd AR, Dore GJ.
http://www.ncbi.nlm.nih.gov/pubmed/23325615

Systemic levels of interferon-gamma-inducible protein-10 (IP-10) are predictive of treatment-
induced clearance in chronic hepatitis C virus (HCV). In the present study, factors
associated with plasma IP-10 levels at the time of acute HCV detection and the association
between IP-10 levels and spontaneous clearance were assessed in three cohorts of acute HCV
infection. Among 299 individuals, 245 (181 male, 47 human immunodeficiency viruspositive
[HIV1]) were HCV RNA1 at acute HCV detection. In adjusted analysis, factors
independently associated with IP-10 levels _150 pg/mL (median level) included HCV RNA
levels >6 log IU/mL, HIV coinfection and non-Aboriginal ethnicity. Among 245 HCV
RNA1 at acute HCV detection, 214 were untreated (n 5 137) or had persistent infection
(infection duration _26 weeks) at treatment initiation (n 5 77). Spontaneous clearance
occurred in 14% (29 of 214).

Individuals without spontaneous clearance had significantly higher mean plasma IP-10 levels at the time of acute HCV detection than those with clearance (248 6 32 versus 142 6 22 pg/mL, P 5 0.008). The proportion of individuals with spontaneous clearance was 0% (0 of 22, P 5 0.048) and 16% (27 of 165) and in those with and without plasma IP-10 levels _380 pg/mL. In adjusted analyses, favorable IL28B genotype was associated with spontaneous clearance, while higher HCV RNA level was independently associated with lower odds of spontaneous clearance.

Conclusion: High IP-10 levels at acute HCV detection were associated with failure to spontaneously clear HCV. Patients with acute HCV and high baseline IP-10 levels, particularly >380 pg/mL, should be considered for early therapeutic intervention, and those with low levels should defer therapy for potential spontaneous clearance.