Hepatitis C virus (HCV) related liver fibrosis in people who inject drugs (PWID) at the Stockholm Needle Exchange - evaluated with liver elasticity.

Background and aims: Sharing of unsterile injection equipment among people who inject drugs (PWID) is the major transmission-route for hepatitis C (HCV). HCV is highly prevalent in PWID in the Stockholm needle exchange programme (NEP). The frequency of advanced liver fibrosis among the participants is, however, unknown. Methods: From December 2016 to April 2018, all participants with chronic hepatitis C infection (CHC) were offered liver fibrosis evaluation at the Stockholm NEP, including liver stiffness measurement (LSM), a medical history and expanded blood tests to evaluate APRI and FIB-4 scores. Results: A total of 2037 individuals were enrolled of whom 964 (47.3%) had CHC. LSM was performed in 203 (21.1%) of eligible participants of whom 85% had mild fibrosis (LSM ≤9.4 kPa) and 15% advanced fibrosis (LSM ≥9.5 kPa). APRI >1 and FIB-4 > 3.25 only identified 30% of participants with advanced fibrosis. However, all 31(100%) participants with advanced fibrosis were detected when APRI >1 was combined with an age of ≥40 years and an injection drug use (IDU) duration of ≥15 years. Conclusions: We found that the diagnostic work-up for advanced fibrosis can be simplified with this combination of easily available factors. This allows identification of PWID in need of immediate HCV treatment to prevent further disease progression. Furthermore, LSM can be avoided among PWID with mild fibrosis, identified by age <40 years combined with IDU duration of <15 years and APRI score <1. This strategy enhances the HCV care cascade where LSM is not easily available, and will thus facilitate HCV treatment initiation.