miRNA-26b downregulation in peripheral blood mononuclear cells of patients with hepatitis C associated lymphomas is restored by successful interferon-free antiviral therapy.

Background: Patients with chronic HCV infection are at increased risk of developing B-cell non-Hodgkin lymphoma (B-NHL). Regression of HCV-associated B-NHL (HCV-NHL) can be achieved through HCV eradication using interferon (IFN). However, only about two-thirds of patients with sustained virological response (SVR) also had a consecutive lymphoma response. miRNA-26b is associated with HCV-NHL response to antiviral therapy. Recent data suggest that IFN-free direct-acting antiviral (DAA) regimens also have anti-lymphoma activity in this patient population.

Methods: We report four patients with HCV-NHL who were treated with different IFN-free DAA regimens as oncological monotherapy in our centre between 2015 and 2016. We analysed the virological and lymphoproliferative disease response. Moreover, we analysed miRNA-26b expression in peripheral blood mononuclear cells at different time points during antiviral therapy for all included patients as well as for a total of 10 controls with (n=5) and without (n=5) chronic HCV infection.

Results: All patients had marginal zone lymphoma subtype and received different DAA regimens for 12-24 weeks. All four patients achieved SVR, but only three patients also had lymphoma response (one complete response, two partial responses). One patient showed progression to a high-grade lymphoma subtype after SVR. miRNA-26b expression was generally decreased in patients with HCV-NHL. Moreover, miRNA-26b expression was restored in those HCV-NHL patients with lymphoma response after 6 months (P=0.009).

Conclusions: We have demonstrated that IFN-free DAA treatment of HCV can improve or even cure NHL. miRNA-26b-levels could be a potentially useful biomarker to predict lymphoma response in HCV-NHL patients.