Abstract
A lack of antiviral response in patients with chronic hepatitis C treated with pegylated (PEG)‐interferon (IFN)‐α‐2a + ribavirin (RIBA) may be explained by neutralizing antibodies to IFN‐α‐2a. The aim of this study was to assess neutralizing antibodies to IFN‐α‐2a and IFN levels in non‐responder patients who were re‐treated by PEG IFN‐α‐2a and RIBA for 12 weeks. Non‐responders to a first‐line treatment of PEG IFN‐α‐2a + RIBA were included for treatment with PEG IFN‐α‐2a (180 µg/week) + RIBA (1,000 mg/day if <75 kg, 1,200 mg otherwise) for 48 weeks. HCV RNA was measured at week 12. IFN levels and neutralizing antibodies to IFN‐α‐2a were measured retrospectively on stored sera at baseline and weeks 4 and 12, using a quantitative sandwich ELISA for neutralizing antibodies to IFN‐α‐2a. Twenty‐three patients were non‐responders and 19 patients were responders at week 12 of the initial phase of the second‐line treatment. Non‐responders and responders did not differ statistically: baseline age (median age 47 vs. 50 years), HCV RNA (median 6.8 vs. 6.4 log~10~ copies/ml), gender (70% vs. 73% males), genotype (genotype 1: 91% vs. 80%). The median IFN‐α‐2a levels (pg/ml) at weeks 0, 4, and 12 (interquartile range) did not differ between the 19 responders to initial phase of second‐line treatment and the 23 non‐responders: <3.3 (<3.3–371.4), 1457.3 (106.8–3284.8), and 1,652 (90.8–5,000); 84.5 (3.3–277.4), 1407.4 (120.2–2443.4), and 1620.1 (120.2–2287.1), respectively. Among non‐selected consecutive non‐responder patients, re‐treatment with PEG IFN‐α‐2a + RIBA is associated with virological response regardless of the presence of antibody‐mediated resistance to conventional IFN treatment. J. Med. Virol. 82:2027–2031, 2010. © 2010 Wiley‐Liss, Inc.