Response and predictors of response, to pegylated interferon and ribavirin for chronic hepatitis C patients in Scotland: alanine aminotransferase (ALT) and gamma glutamyl transferase (GGT) are valuable pre-treatment markers of an SVR in routine clinical practice

It is not clear what proportion of HCV (hepatitis C virus) patients attain a sustained viral response (SVR) when treated with pegylated interferon and ribavirin combination therapy outside randomised clinical trials (RCTs). Secondly, pre-treatment factors available in routine clinical settings that are predictive of SVR (the optimal treatment outcome) are not known. HCV clinical databases from nine Scottish treatment clinics were used to derive a retrospective cohort of 934 patients initiated on HCV treatment during 2000–2007. In our cohort, 39% (123/315, 95% CI 34% to 45%) of genotype (GT) 1, and 70% (414/594, 95% CI 66% to 73%) of genotype 2/3 (GT2/3) patients achieved a SVR; this compares with pooled estimates of 47% for GT1 (95% CI 41% to 52%), and 80% for GT2/3 (95% CI 75% to 85%) patients from RCTs. Pre-treatment factors significantly associated with SVR were: gamma glutamyl transferase (GGT) ≥55 IU/l (adjusted OR: 0.46, 95% CI 0.33 to 0.65), platelet count ≥150×109/l (1.92, 95% CI 1.26 to 2.93), ALT quotient ≥2.5 (for those GT1 infected: 2.66, 95% CI 1.46 to 4.84), GT2/3 (for those with ALT quotient <2.5: 4.05, 95% CI 2.82 to 5.80; and for those with ALT quotient ≥2.5: 1.91, 95% CI 1.01 to 3.61), age (per ten year increase) (0.84, 95% CI 0.72 to 0.99), ever HBV infection (0.67, 95% CI 0.45 to 0.98), and male gender (0.70, 95% CI 0.50 to 0.98). The principal conclusions are twofold: (1) the proportion of patients attaining a SVR in Scottish routine practice is marginally lower than in RCTs, and (2) in addition to genotype, GGT (in all patients) and ALT (in GT1 patients only) emerge as valuable predictors of an SVR in the routine clinical setting.