Introducing treat-to-target strategies of autoimmune extrahepatic manifestations of chronic hepatitis C virus infection

Hepatitis C virus-related vasculitis

Cryoglobulinemic vasculitis (CryoVas) is a small-to-medium vessel systemic vasculitis caused by the deposition of mixed cryoglobulins and immune complexes. Clinical spectrum of CryoVas ranges from mild symptoms to vasculitis involving multiple organs that may progress to more life-threatening ilness. Hepatitis C virus (HCV) chronic infection is the most frequent condition to be assessed in patients with CryoVas. The mortality rate among patients with HCV-associated CryoVas is 3× that of the general population, with a 63% 10-year survival rate. The recent advent of interferon-free direct-acting antivirals (DAAs), which have the potential to induce sustained virological response rates greater than 95%, has dramatically changed the management of chronic HCV infection and HCV-related CryoVas. B-cell depleting strategies, mainly with rituximab, are the main therapeutic option in severe and refractory cases of HCV-associated CryoVas. Despite the progress in the last years on the management of chronic HCV infection, there are still unmet needs regarding therapeutic management of severe and refractory HCV-associated CryoVas.

Systematic review with meta-analysis: extrahepatic manifestations in chronic hepatitis C virus-infected patients in East Asia

BACKGROUND

Although the prevalence of extrahepatic manifestations of chronic hepatitis C virus (HCV) infection has been reported from Western countries, their prevalence in East Asian countries is not well known.

AIM

To perform a systematic review to quantify the prevalence of selected extrahepatic manifestations of HCV among patients from East Asia.

METHODS

Medline, CINAHL, EMBASE, Cochrane and country-specific databases were reviewed according to standard guidelines for meta-analyses. Only articles with patients from East Asian countries were included.

RESULTS

After review, 34 articles were selected (Japan = 9; China = 5, Korea = 3, Taiwan = 16, multiple countries = 1) with 646 228 subjects, 66 436 with HCV. Mean age for HCV-infected patients was 56 years (range 41-72 years), 50% were male (range 26%-73%). The pooled prevalence of type 2 diabetes in East Asian HCV patients was 19.0% (95% confidence interval 15.6%-22.9%) (n = 19 studies) with an increased risk when compared to non-HCV: odds ratio (OR) 1.58 (1.28-1.94). The prevalence of chronic kidney disease in HCV was 9.2% (5.0%-16.2%) (n = 7 studies), also with a significantly increased risk: OR=1.98 (1.41-2.77). Pooled prevalence of cardiovascular disease in HCV was 8.6% (3.5%-19.9%) (n = 6 studies), also with an increased risk: OR = 1.55 (1.21-1.98). The prevalence of lichen planus in HCV was 8.9% (3.6%-20.6%) (n = 6 studies) while the prevalence of rheumatoid arthritis was 4.5% (0.6%-25.7%) (n = 4 studies).

CONCLUSIONS

These data show increased risk of developing extrahepatic manifestations in East Asian patients with HCV. Both hepatic and extrahepatic manifestations of the infection should be used to accurately determine the total burden of the disease in the region.

Modulation of the Immune System in Chronic Hepatitis C and During Antiviral Interferon-Free Therapy

The treatment of patients with chronic hepatitis C virus (HCV) infection has changed tremendously over the past 2 years, with an increasing variety of all-oral direct-acting antiviral (DAA) treatment regimens available for different HCV genotypes and distinct clinical settings. These treatments have significantly improved safety in patients with advanced liver disease compared with interferon (IFN)-based regimens. HCV modifies the human immune system to escape immunosurveillance via several mechanisms. One of the basic mechanisms of HCV is the ability to “switch” the immune response by reducing the activity of cells responsible for the elimination of virus-infected cells. IFN-free DAA treatment regimens provide a unique opportunity to assess the effect of HCV elimination on the immune system. Abrupt changes in the immune system can in some cases be responsible for two alarming processes: viral reactivation in patients with chronic hepatitis B and recurrence of hepatocellular carcinoma in patients with previous successful cancer treatment.

Cryoglobulinaemia

Cryoglobulinaemia refers to the serum presence of cryoglobulins, which are defined as immunoglobulins that precipitate at temperatures <37 °C. Type I cryoglobulinaemia consists of only one isotype or subclass of monoclonal immunoglobulin, whereas type II and type III are classified as mixed cryoglobulinaemia because they include immunoglobulin G (IgG) and IgM. Many lymphoproliferative, infectious and autoimmune disorders have been associated with mixed cryoglobulinaemia; however, hepatitis C virus (HCV) is the aetiologic agent in most patients. The underlying mechanism of the disorder is B cell lymphoproliferation and autoantibody production. Mixed cryoglobulinaemia can cause systemic vasculitis, with manifestations ranging from purpura, arthralgia and weakness to more serious lesions with skin ulcers, neurological and renal involvement. This Primer focuses on mixed cryoglobulinaemia, which has a variable course and a prognosis that is primarily influenced by vasculitis-associated multiorgan damage. In addition, the underlying associated disease in itself may cause considerable mortality and morbidity. Treatment of cryoglobulinaemic vasculitis should be modulated according to the underlying associated disease and the severity of organ involvement and relies on antiviral treatment (for HCV infection), immunosuppression and immunotherapy, particularly anti-CD20 B cell depletion therapies.