Hepatitis C virus-related autoimmunity before and after viral clearance: a single center, prospective, observational study.

Background: Hepatitis C virus (HCV) chronic infection is frequently associated to autoimmune manifestations. The aim of this study was to prospectively evaluate the occurrence of clinical and/or laboratory features of autoimmunity in a cohort of 140 consecutive HCV chronically infected patients treated with direct-acting antiviral agents (DAAs) and followed-up for 96 weeks.

Methods: All patients were screened for cryoglobulins, rheumatoid factor (RF), C3, C4, antinuclear antibody (ANA), anti-smooth muscle (ASMA), anti-liver kidney microsome type 1 (anti-LKM1), anti-mitochondrial antibodies (AMA), anti-neutrophil cytoplasmic antibodies (ANCA), and anti-liver cytosol type 1/soluble liver antigen (anti-LC1/SLA) autoantibodies before therapy and 12, 48 and 96 weeks after treatment. They were then grouped according to the expression of laboratory findings and related autoimmune diseases.

Results: At baseline, autoimmune manifestations were found in 70 patients: 83% of them were cryoglobulinemic, whereas ANA, AMA, perinuclear ANCA (pANCA) and LKM/LC1 autoantibodies were found in the remaining 17%. An autoimmune disease was diagnosed in 9 cases, two of them featuring an autoimmune liver disease (AILD). At the end of follow-up, despite viral clearance and regression of vasculitis, cryoglobulins persisted in 12 patients (21%), and autoantibodies disappeared or decreased in most of cases but, with the exception of the 2 patients diagnosed as AILD, associated autoimmune diseases remained stable. In one patient with relapsing cryoglobulinemia and ANA positivity, type-1 autoimmune hepatitis was defined. Conversely, autoantibodies first appeared after viral clearance in 5 patients, of whom one was diagnosed with type-1 autoimmune hepatitis and one with pANCA+ primary sclerosing cholangitis.

Conclusions: Following DAA-induced viral clearance, cryoglobulins may persist or reappear. Autoantibodies changed dynamically in step with the disappearance of a previously diagnosed or the occurrence of a new AILD. A longer follow-up will be necessary to establish the possible diagnosis of a newly onset AILD, the reactivation of cryoglobulinemic vasculitis and even its progression to non-Hodgkin lymphoma.