Molecular characterization of HCV in a Swedish county over 8 years (2002-2009) reveals distinct transmission patterns

Prevalence of chronic hepatitis C virus infection among childhood cancer survivors in Stockholm, Sweden

Background: Childhood cancer survivors treated before 1992, when blood donor screening for hepatitis C virus (HCV) infection was introduced, are at risk of transfusion-transmitted HCV infection. A national HCV screening campaign targeting blood transfusion recipients was launched in Sweden in 2007-2010. The aims of this study were to, among adult childhood cancer survivors in Stockholm County, investigate the prevalence of HCV infection, the natural course of infection, treatment outcome and anti-HCV testing frequency before, during and after the screening campaign and finally to actively screen the untested ones. Material and Methods: This was a combined retrospective register based and prospective screening study of adult childhood cancer survivors (n = 686) treated for malignancy in Stockholm before 1992. In the first part, we investigated the prevalence of HCV infection and previous anti-HCV testing, and in the second part, we actively traced and HCV-screened the remaining untested cohort living in Stockholm. Analysis of previous documented anti-HCV tests in medical records, laboratory records, and the national communicable disease registry was performed. In the second part, 231 presumably untested individuals were contacted by mail and offered an anti-HCV test. The natural course of HCV infection and treatment outcome was analyzed for those found to be chronically infected. Results: In total, 235 patients were tested and 11 were HCV-RNA positive. The overall prevalence of chronic HCV infection among the tested childhood cancer survivors was thus 4.7% (95% CI = 2.6-8.2%), which is almost 10 times higher than the national prevalence of 0.5%. Only 12% of the Stockholm cohort were tested during the screening campaign in 2007-2010, while the test uptake using active tracing screening within this study was 40% (p < .001). Conclusion: With today's effective treatment options, active tracing and HCV screening of childhood cancer survivors are recommended.

The effect of the first-generation HCV-protease inhibitors boceprevir and telaprevir and the relation to baseline NS3 resistance mutations in genotype 1: experience from a small Swedish cohort

BACKGROUND

The clinical experience with protease-inhibitor (PI) triple regimen appears disappointing regarding effect, side effects, high work load, and costs. This real-world study evaluates baseline and emerging resistance-associated substitutions (RASs) and their significance for treatment outcome.

METHOD

Thirty-six genotype 1a/b patients treated according to Swedish recommendations during 2011-2013 with triple therapy including pegylated interferon and ribavirin in combination with a protease-inhibitor, either boceprevir (BOC) or telaprevir (TVR), were retrospectively evaluated. Frozen serum samples from the patients were tested for resistance with pan-genotypic population sequencing.

RESULTS

Overall, 56% (20/36) of the patients achieved sustained viral response (SVR). The SVR was comparable between BOC (64%; 9/14) and TVR (50%; 11/22) (p = 0.07), and the IL28B type non-CC (48%; 12/25) and CC (46%; 6/13) (p = 0.77). The SVR was higher in patients without cirrhosis (89.5%; 17/19) (p < 0.0005), in treatment-naïve patients (70%; 14/20) (p = 0.02), and those with low viral load (<800,000 IU/mL) (66.7%; 8/12) (p < 0.0002), compared to those with cirrhosis (17.6%; 3/17), treatment-experienced (37.5%; 6/16), and high viral load (>800,000 IU/mL) (50%; 12/24).

CONCLUSION

PI triple regimes were highly effective in treatment-naïve patients without cirrhosis, but in this real-world cohort an inferior effect was evident in cirrhotic and treatment-experienced patients. Although tested on a limited sample, the baseline resistance testing seems to have no impact on prediction of therapy outcome. The reason could be that the baseline RASs T54S and V55A have relatively low resistance towards BOC and TVR. Emerging RASs, mainly R155K, with known high resistance to BOC and TVR were frequently found in non-responders.