Effects of combined antiviral therapy on asymptomatic mixed cryoglobulinemia in naive patients with chronic hepatitis C virus infection: a preliminary study

Hepatitis E virus-associated cryoglobulinemia in solid-organ-transplant recipients

BACKGROUND & AIMS

An association between hepatitis E virus (HEV) infection and cryoglobulinemia has been suggested. The aims of this study were to assess the prevalence of cryoglobulinemia during HEV infection in solid-organ-transplant (SOT) recipients, to describe its outcomes under ribavirin therapy and to evaluate its effects on kidney function and histology.

METHODS

Between November 2005 and June 2016, 128 cases of HEV infection were diagnosed among SOT recipients followed in our institution. Cryoglobulinemia data obtained from 66 patients during acute-phase HEV and 51 patients during chronic-phase HEV were compared to a historical control group of 89 SOT recipients without HEV markers. Cryoglobulins were also monitored in a group of 43 patients treated by ribavirin.

RESULTS

The prevalence of cryoglobulinemia was increased in HEV-infected SOT patients during a chronic phase (52.9%) compared to HEV-infected SOT patients at acute phase (36.4%) (P = .1) and to HEV-negative SOT patients (23.6%) (P < .001). HEV infection was identified as an independent predictive factor for cryoglobulinemia (OR 2.3, CI 95%: 1.17-4.55, P = .02). After ribavirin therapy and HEV clearance, the prevalence of cryoglobulin was significantly decreased from 53.5% to 20.9% (P = .003). Kidney function was significantly worse and proteinuria tended to be higher in chronically HEV-infected patients with cryoglobulinemia compared to those without cryoglobulinemia. Membranoproliferative glomerulonephritis was diagnosed in 2 patients, of which 1 had detectable cryoglobulinemia.

CONCLUSIONS

In conclusion, a relationship between HEV and cryoglobulin formation seems to exist. However, the clinical impact of cryoglobulinemia in SOT patients infected with HEV has to be confirmed.

Virologic, Clinical, and Immune Response Outcomes of Patients With Hepatitis C Virus-Associated Cryoglobulinemia Treated With Direct-Acting Antivirals

BACKGROUND & AIMS

Cryoglobulins (circulating immune complexes of polyclonal IgG, monoclonal IgM, and rheumatoid factor) are detected in the circulation of 40% to 60% of patients with chronic hepatitis C virus infection, and cryoglobulinemic vasculitis (CV) is observed in approximately 10% of patients. We aimed to assess the clinical and immune effects of direct-acting antiviral treatment.

METHODS

We performed a prospective study of 64 patients with HCV infection with circulating cryoglobulins receiving direct-acting antiviral therapy at a single center in Barcelona, Spain, from January 2014 through April 2016. Patients were classified as having CV (n = 35) or asymptomatic circulating cryoglobulins (ACC, n = 29). Clinical response was considered complete if a patient's Birmingham Vasculitis Activity Score (version 3) was 0, or if all affected organs improved 12 weeks after the end of therapy. A complete immunologic response (CIR) was defined as no detection of circulating cryoglobulins and normalized levels of complement and/or rheumatoid factor.

RESULTS

Clinical manifestations of CV included purpura (65%), weakness (70%), arthralgia (31%), myalgia (20%), peripheral neuropathy (50%), and renal involvement (20%). At baseline, patients with CV had significantly higher levels of rheumatoid factor and lower levels of C4 complement than patients with ACC, whereas cryocrits were similar between groups (3.2% vs 2.6%). Overall, 60 patients (94%) had a sustained viral response 12 weeks after therapy. Among patients with CV, the median Birmingham Vasculitis Activity Score (version 3) decreased from 9 (range, 2-31) to 3 (range, 0-12) (P < .001). Twenty-five patients with CV (71%) achieved a complete clinical response. Immune-suppressive therapy was reduced for 4 of 13 patients and withdrawn for 6 of 13. Overall, 48% of patients achieved a CIR. A low baseline cryocrit level (<2.7%) was the only factor associated with CIR (odds ratio, 9.8; 95% confidence interval, 2.2-44; P = .03).

CONCLUSIONS

Viral eradication was associated with clinical improvement in most patients with CV. Markers of immune activation, including circulating cryoglobulins, persisted in 52% of patients with CV or ACC, despite a sustained viral response 12 weeks after therapy. A longer follow-up period after viral eradication might be necessary to ensure a normal immune response.

Treatment of hepatitis C cryoglobulinemia: mission and challenges

Mixed cryoglobulinemia (MC) is a syndrome resulting from cold-insoluble immunoglobulin complexes or cryoglobulins (CGs) that precipitate in the serum of 40% to 50% of patients with chronic hepatitis C virus (HCV) infection. The pathogenesis of cryoglobulinemia likely occurs due to chronic viremia and generation of rheumatoid factor following continuous presentation of antigen-immunoglobulin complexes to B cells. CGs are thought to be responsible for a variety of extrahepatic manifestations associated with HCV, including vasculitis, glomerulonephritis, arthritis, and neuropathies, which occur in approximately 10% of HCV patients with CGs. CGs also are a powerful predictive factor for progressive liver disease and the aggressive reoccurrence of liver disease in HCV-positive patients after liver transplantation. First-line therapy for MC due to HCV infection is antiviral therapy with pegylated interferon-alpha and ribavirin. Viral eradication usually produces marked reduction of physical complications and arrests end organ damage concomitant with clearance of CG. Additional prospective, controlled studies are necessary to determine whether CG influences patient virologic response and/or its durability to antiviral therapy. Immunomodulators such as corticosteroids and cyclophosphamide are efficacious for palliative treatment of the symptomatology of HCV cryoglobulinemia but may enhance viral replication. Consequently, prolonged therapy with immunomodulatory agents should be limited to severe vasculitis or aggressive glomerulonephritis in patients with MC due to HCV who have failed to respond to antiviral therapy. In acute, fulminant presentations, plasmapheresis may provide temporary relief and arrest the rapid progression of the disease so that additional therapy can be initiated.

Hepatitis C: the complications of immune dysfunction

Hepatitis C virus (HCV) infection has been linked to numerous diseases of immune dysfunction, including, but not limited to, essential mixed cryoglobulinemia and non-Hodgkin's lymphoma. Clinical studies support these associations and treatment of the underlying HCV infection has been variably successful. Recent studies, focusing on the role of HCV gene products, have discovered evidence of dysregulated responses in multiple aspects of host immunity that may be contributing to the genesis of these diseases. Novel treatments that target these areas of dysregulation offer hope for improved therapy for the diseases associated with immunodysregulation by HCV.

Abnormal B-cell activation associated with TALL-1 over-expression and SOCS-1 suppression during chronic hepatitis C virus infection

Chronic hepatitis C virus (HCV) infection is associated with cirrhosis, autoimmunity and lymphoproliferative disorders. We have previously reported a differential regulation of T and B lymphocytes by HCV core protein in vitro. In this report, we employed a translational approach to characterize the activation status of peripheral B cells from individuals with chronic HCV infection and to explore potential mechanisms for B-cell dysregulation in the setting of HCV infection. In contrast to the T-cell suppression observed in HCV-infected individuals, B cells exhibit a non-specific polyclonal activation phenotype, characterized by significantly higher levels of (1) the early activation marker, CD69, (2) the costimulatory molecule, CD86, and (3) the CCR5 chemokine receptor, CD195, when compared with B cells from healthy donors in response to phytohaemagglutinin (PHA) stimulation. Importantly, tumour necrosis factor- and Apo-L-related leucocyte-expressed ligand-1 (TALL-1), also known as B-lymphocyte stimulator (BLYS), was found to be up-regulated on the surface of B cells from HCV patients in response to PHA as well as HCV core antigen stimulation. This up-regulation of TALL-1 was associated with vigorous memory B-cell responses to viral antigenic stimulation. Additionally, suppressor of cytokine signalling-1 (SOCS-1), a negative feedback immunoregulator that is inhibited in B lymphocytes by HCV core in vitro, was also inhibited in B cells from HCV patients when compared with healthy donors. These findings suggest that TALL-1 over-expression and SOCS-1 suppression are associated with aberrant B-cell activation, providing a plausible basis for the B-cell clonal expansion underlying the lymphoproliferative disorders and autoimmune phenomena observed during chronic HCV infection.

Long-term outcomes after treatment with interferon and ribavirin in HCV patients

Hepatitis C is a leading indication for transplantation and a common cause of liver-related death worldwide. Treatment for hepatitis C has evolved from interferon therapy alone, which yielded relatively poor response rates compared with the currently recommended and more effective combination of pegylated interferon and ribavirin. Factors such as hepatitis C viral genotype, pretreatment viral load, race, renal function, degree of hepatic fibrosis, and comorbid conditions such as HIV coinfection have clinical importance in that they influence viral kinetics, which play a large role in determining a sustained response to therapy or virologic "cure." However, the goal of therapy is to reduce liver-related morbidity and mortality by decreasing rates of progression or improvement of fibrosis, reducing risk of hepatocellular carcinoma, improving posttransplant graft and patient survival, and resolving or improving some of the extrahepatic manifestations of hepatitis C. Studies generally infer long-term success from the more tangible goal of sustained viral suppression; however, increasing data suggest that effective therapy does result in decreased morbidity and mortality. Given the heterogeneity of patients who are infected with hepatitis C, treatment decisions should be specifically tailored to each individual patient on the basis of their predisposing conditions and anticipated clinical outcomes.

Differential regulation of SOCS-1 signalling in B and T lymphocytes by hepatitis C virus core protein

Hepatitis C virus (HCV) infection is characterized by a strong propensity toward chronicity, autoimmune phenomena and lymphomagenesis, supporting a role for lymphocyte dysregulation during persistent viral infection. We have shown that HCV core protein inhibits T-cell functions through interaction with a complement receptor, gC1qR. Here, we further report that B cells also express gC1qR that can be bound by HCV core protein. Importantly, using flow cytometry, we demonstrated differential regulation of B and T lymphocytes by the HCV core-gC1qR interaction, with down-regulation of CD69 activation in T cells but up-regulation of CD69 activation and cell proliferation in B cells. HCV core treatment led to decreased interferon-gamma production in CD8+ T cells but to increased immunoglobulin M and immunoglobulin G production as well as cell surface expression of costimulatory and chemokine receptors, including CD86 (B7-2), CD154 (CD40L) and CD195 (CCR5), in CD20+ B cells. Finally, we showed down-regulation of suppressor of cytokine signalling-1 (SOCS-1) using real-time reverse transcription-polymerase chain reaction, accompanied by up-regulation of signal transducer and activator of transcription-1 (STAT1) phosphorylation in B cells in response to HCV core protein, with the opposite pattern observed in HCV core-treated T cells. This study demonstrates differential regulation of B and T lymphocytes by HCV core and supports a mechanism by which lymphocyte dysregulation occurs in the course of persistent HCV infection.