Impact of direct acting antivirals on hepatitis C virus-related cryoglobulinemic syndrome

INTRODUCTION: Mixed cryoglobulinemia (MC) is a B-cell lymphoproliferative disorder largely attributable to Hepatitis C virus (HCV) infection. MC clinical manifestations are determined by systemic vasculitis of low/medium sized vessels (mixed cryoglobulinemia syndrome or cryoglobulinemic vasculitis [CV]) caused by the deposition of cryoglobulins in blood vessels. EVIDENCE ACQUISITION: A systematic review was performed via the Medline and Scopus databases to evaluate studies concerning CV treatment with new direct antiviral agents (DAAs) and their effect on the syndrome. EVIDENCE SYNTHESIS: The introduction of interferon-free protocols has led to more evident positive effects than those observed in the treatment of hepatitis C. In fact, IFN-free, DAA-based therapy minimized side effects permitting the treatment of previously contraindicated patients and led to a particularly high SVR rate and to a clinical/immunological response in the majority of patients, even if at different levels in different patients, from restitutio ad integrum to partial response. In view of the clearly positive evolution in CV management, the persistence of CV manifestations, in partial or non-responders continues to pose problems in the clinical approach to patients who represent a new condition that is still not completely known. CONCLUSIONS: Results of DAA-based therapy strongly confirm the use of anti-HCV therapy as the first-line therapeutic option in CV patients. However, growing evidence of a possible persistence or late relapse of CV suggests the need for longer/more accurate post-DAA follow-ups as well as biomarkers that are capable of predicting the risk of clinical relapse/persistence to allow for the design of rational post-HCV eradication clinical flow-charts.