The challenge of treating hepatitis C virus-associated cryoglobulinemic vasculitis in the era of anti-CD20 monoclonal antibodies and direct antiviral agents

Exploring T-Cell Immunity to Hepatitis C Virus: Insights from Different Vaccine and Antigen Presentation Strategies

The hepatitis C virus (HCV) is responsible for approximately 50 million infections worldwide. Effective drug treatments while available face access barriers, and vaccine development is hampered by viral hypervariability and immune evasion mechanisms. The CD4+ and CD8+ T-cell responses targeting HCV non-structural (NS) proteins have shown a role in the viral clearance. In this paper, we reviewed the studies exploring the relationship between HCV structural and NS proteins and their effects in contributing to the elicitation of an effective T-cell immune response. The use of different vaccine platforms, such as viral vectors and virus-like particles, underscores their versability and efficacy for vaccine development. Diverse HCV antigens demonstrated immunogenicity, eliciting a robust immune response, positioning them as promising vaccine candidates for protein/peptide-, DNA-, or RNA-based vaccines. Moreover, adjuvant selection plays a pivotal role in modulating the immune response. This review emphasizes the importance of HCV proteins and vaccination strategies in vaccine development. In particular, the NS proteins are the main focus, given their pivotal role in T-cell-mediated immunity and their sequence conservation, making them valuable vaccine targets.

The art of managing hepatitis C virus in special population groups: a paradigm shift

The first direct-acting antiviral (DAA) medications were approved for the treatment of chronic hepatitis C virus (HCV) in 2011. Later, the appearance of novel DAAs had revolutionized the landscape of HCV treatment whose early treatment options were limited to interferon (IFN) either alone or in combinations. This review discusses the paradigm shift in legibility for treating different groups of patients with HCV after the introduction of DAAs, along with the consequent changes in treatment guidelines. IFN-based therapy was the firstly used for treating chronic HCV. Unfortunately, it exhibited many pitfalls, such as low efficacy in some patients and unsuitability for usage in lots of patients with some specific conditions, which could be comorbidities such as autoimmune thyroiditis, or liver related as in decompensated cirrhosis. Furthermore, IFN failed to treat all the extrahepatic manifestations of HCV. Nowadays, the breakthroughs brought by DAAs have benefited the patients and enabled the treatment of those who could not be treated or did not usually respond well to IFN. DAAs achieve a high success rate of HCV eradication in addition to avoiding unfavorable harms and, sometimes, adverse effects related to the previously used PEGylated IFN regimens.

Autoantibodies and Rheumatologic Manifestations in Hepatitis C Virus Infection

HCV is a virus that can cause chronic infection which can result in a systemic disease that may include many rheumatologic manifestations such as arthritis, myalgia, sicca syndrome, cryoglobulinemia vasculitis as well as other non-rheumatological disorders (renal failure, onco-haematological malignancies). In this population, the high frequency of rheumatoid factor (45-70%), antinuclear (10-40%) and anticardiolipin (15-20%) antibodies is a B-cell mediated finding sustained by the infection. However, the possibility that a primitive rheumatic pathology may coexist with the HCV infection is not to be excluded thus complicating a differential diagnosis between primitive and HCV-related disorders.

The Role of B Cells in Adult and Paediatric Liver Injury

B lymphocytes are multitasking cells that direct the immune response by producing pro- or anti-inflammatory cytokines, by presenting processed antigen for T cell activation and co-stimulation, and by turning into antibody-secreting cells. These functions are important to control infection in the liver but can also exacerbate tissue damage and fibrosis as part of persistent inflammation that can lead to end stage disease requiring a transplant. In transplantation, immunosuppression increases the incidence of lymphoma and often this is of B cell origin. In this review we bring together information on liver B cell biology from different liver diseases, including alcohol-related and metabolic fatty liver disease, autoimmune hepatitis, primary biliary and primary sclerosing cholangitis, viral hepatitis and, in infants, biliary atresia. We also discuss the impact of B cell depletion therapy in the liver setting. Taken together, our analysis shows that B cells are important in the pathogenesis of liver diseases and that further research is necessary to fully characterise the human liver B cell compartment.

Secondary Membranous Nephropathy. A Narrative Review

Membranous nephropathy (MN) is a common cause of proteinuria and nephrotic syndrome all over the world. It can be subdivided into primary and secondary forms. Primary form is an autoimmune disease clinically characterized by nephrotic syndrome and slow progression. It accounts for ~70% cases of MN. In the remaining cases MN may be secondary to well-defined causes, including infections, drugs, cancer, or autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), urticarial vasculitis, sarcoidosis, thyroiditis, Sjogren syndrome, systemic sclerosis, or ankylosing spondylitis. The clinical presentation is similar in primary and secondary MN. However, the outcome may be different, being often related to that of the original disease in secondary MN. Also, the treatment may be different, being targeted to the etiologic cause in secondary MN. Thus, the differential diagnosis between primary and secondary MN is critical and should be based not only on history and clinical features of the patient but also on immunofluorescence and electron microscopy analysis of renal biopsy as well as on the research of circulating antibodies. The identification of the pathologic events underlying a secondary MN is of paramount importance, since the eradication of the etiologic factors may be followed by remission or definitive cure of MN. In this review we report the main diseases and drugs responsible of secondary MN, the outcome and the pathogenesis of renal disease in different settings and the possible treatments.

Cryoglobulinemic glomerulonephritis: clinical presentation and histological features, diagnostic pitfalls and controversies in the management. State of the art and the experience on a large monocentric cohort treated with B cell depletion therapy

Cryoglobulinemia is defined by the presence of immunoglobulins having the following characteristics: forming a gel when temperature is <37 °C, precipitate in a reversible manner in the serum, and redissolve after rewarming. The presence of both polyclonal IgG and monoclonal IgM (type II), or of polyclonal IgG and polyclonal IgM (type III) identifies the mixed cryoglobulinemia (MC). The identification of the Hepatitis C virus (HCV) infection in most of the cases previously defined as "essential" represented a cornerstone in the understanding the pathogenesis of this condition. The picture of MC comprehends heterogeneous clinical presentations: from arthralgias, mild palpable purpura, fatigue to severe vasculitis features with skin necrotic pattern, peripheral neuropathy and, less commonly, lungs, central nervous system, gastrointestinal tract, and heart involvement. The kidney represents the most common organ presentation, and the presence of glomerulonephritis is a key element when considering prognosis. We discuss the clinical presentation and histological features, diagnostic pitfalls, and controversies in the management of patients with cryoglobulinemic glomerulonephritis, with a special focus on reporting our experience in treating patients with B cell depletion therapy.

Rheumatologic manifestations of hepatitis C in the era of direct-acting antiviral agents

Beyond the classic hepatic complications, hepatitis C (HCV) infection is considered as a systemic disease, since extrahepatic manifestations become clinically evident in 40% to 70% of the patients and it can frequently include rheumatic ones. Furthermore, HCV can promote the production of several autoantibodies, thus complicating the differential diagnosis between primitive and HCV-related rheumatic disorders. The recent development of direct-acting antivirals (DAA) against HCV has revolutionized the field, reducing the damage stemming from systemic inflammatory phenomena and persistent immune activation associated with continuous HCV replication. Our review focuses on the main rheumatologic manifestations associated with chronic HCV infection as well as the impact of DAA interferon-free treatments on such extrahepatic clinical involvement.

Direct-Acting Antiviral Agents for HCV-Associated Glomerular Disease and the Current Evidence

Glomerular disease is an extra-hepatic manifestation of hepatitis C virus infection (HCV) and membranoproliferative glomerulonephritis is the most frequent glomerular disease associated with HCV. It occurs commonly in patients with HCV-related mixed cryoglobulinemia syndrome. Patients with HCV-related glomerular disease have been historically a difficult-to-treat group. The therapeutic armamentarium for HCV-related glomerular disease now includes antiviral regimens, selective or non-specific immunosuppressive drugs, immunomodulators, and symptomatic agents. The treatment of HCV-associated glomerular disease is dependent on the clinical presentation of the patient. The recent introduction of all-oral, interferon (IFN)-free/ribavirin (RBV)-free regimens is dramatically changing the course of HCV in the general population, and some regimens have been approved for HCV even in patients with advanced chronic kidney disease. According to a systematic review of the medical literature, the evidence concerning the efficacy/safety of direct-acting antiviral agents (DAAs) of HCV-induced glomerular disease is limited. The frequency of sustained virological response was 92.5% (62/67). Full or partial clinical remission was demonstrated in many patients (n = 46, 68.5%) after DAAs. There were no reports of deterioration of kidney function in patients on DAAs. Many patients (n = 29, 43%) underwent immunosuppression while on DAAs. A few cases of new onset or relapsing glomerular disease in patients with HCV successfully treated with DAAs have been observed. In summary, DAA-based combinations are making easier the management of HCV. However, patients with HCV-induced glomerular disease are still a difficult-to-treat group even at the time of DAAs.

Clinical outcome of HCV-associated cryoglobulinemic glomerulonephritis following treatment with direct acting antiviral agents: a case-based review

Newer treatment protocols involving direct-acting antiviral agents (DAAs) have been associated with high rates of sustained virologic response (SVR) and clinical remission in patients with hepatitis C virus (HCV) associated cryoglobulinemic vasculitis (HCV-CV), but clinical response in those with renal involvement is less clear. Our goal was to evaluate the clinical course following DAA therapy in one of the largest cohorts of patients with HCV-associated cryoglobulinemic glomerulonephritis (HCV-GN) reported to date. This is an observational study of patients with chronic HCV infection and circulating cryoglobulins (CC) treated with DAAs in our department from January 2015 to January 2019. We identified a total of 67 patients with HCV and CC out of which nine patients fulfilled the criteria of HCV-GN and had adequate clinical follow-up time. We describe a cohort of nine patients with a mean age of 57 years and known duration of HCV infection ranging 3-20 years (four with evidence of compensated cirrhosis). All patients received the ritonavir-boosted paritaprevir/ombitasvir/dasabuvir regimen for 12 weeks and achieved SVR without subsequent viral relapse. Following DAAs completion, one patient developed "new-onset" cryoglobulinemic glomerulonephritis, six showed either persistent or worsening glomerulonephritis, and only two patients had a complete clinical response (CCR). Of the six patients with either persistent or worsening CV, 67% received additional immunosuppressive (IS) therapy for uncontrolled CV. Of the two patients that had a CCR, one patient received prior IS therapy while the other one improved without any additional intervention. Newer HCV treatment protocols involving DAAs are highly successful in eradication of HCV infection; however, in our experience, DAA treatment alone is insufficient in improving the renal outcomes of patients with HCV-GN and additional IS therapies should be considered.

Clinical practice: hepatitis C virus infection, cryoglobulinemia and cryoglobulinemic vasculitis

Cryoglobulins are circulating immunoglobulins that reversibly precipitate at temperatures below 37 °C. Type-II cryoglobulins consist of monoclonal IgM/polyclonal IgG immune complexes (ICs), whereas in type-III cryoglobulins both IgM and IgG are polyclonal. The clinical condition resulting from the presence of cryoglobulins in the blood is called mixed cryoglobulinemia (MC), which can be asymptomatic or manifest as cryoglobulinemic vasculitis (CV). Type-I cryoglobulins, consisting of a single monoclonal isotype, are detected in patients with lymphoproliferative disorders. It is now established that > 90% of MCs are associated with HCV infection. Clinically, the spectrum of symptoms may range in severity from occasional purpuric eruptions to life-threatening features. In addition to the development of liver cirrhosis and hepatocellular carcinoma, the possible progression of HCV-positive CV patients to B-cell non-Hodgkin lymphoma (B-NHL) has been reported. The pathogenetic role played by HCV infection in the onset of B-NHL is suggested by regression of the latter following the achievement of a sustained virologic response (SVR). For several years, interferon-α alone or combined with ribavirin has been the standard of care. However, the rates of clinical, biochemical, and virologic responses have been low, and the occurrence of relapse frequent. The addition of rituximab has resulted in a higher rate of responses. With the advent of direct-acting antiviral agents, SVR has been achieved in ~ 95% of CV patients. However, in a minority of patients, despite SVR, CV may persist or reappear over variable lengths of time from the completion of therapy. The eventual appearance of B-NHL is also possible.

Interleukin-17A and B-cell activating factor in chronic hepatitis C patients with or without asymptomatic mixed cryoglobulinemia: effects of antiviral treatment and correlations with vitamin D

BACKGROUND

Several studies have provided conflicting results regarding the immune responses in chronic hepatitis C (CHC) patients with mixed cryoglobulinemia (MC). The importance of B-cell activating factor (BAFF) in MC has been described, but the role of interleukin (IL)-17A is less clear.

METHODS

Serum concentrations of IL-17A, BAFF and 25-OH vitamin D were measured in CHC patients at baseline, end of treatment, and 6 months post-treatment with pegylated interferon-α and ribavirin, versus 12 healthy controls.

RESULTS

Thirty-four patients (20 male, mean age 40.7±9.2 years, 12 of genotype 1 or 4, 22 of genotype 2 or 3) were included, of whom 64.7% achieved a sustained virological response (SVR). MC was detected in 52.9% of the patients. Higher levels of both cytokines were found in patients with MC compared to those without. Patients who achieved SVR had higher pretreatment IL-17A and lower BAFF levels compared to those without SVR. IL-17A was downregulated during and following treatment in responders, whereas upregulation was observed in non-responders. CHC patients demonstrated low vitamin D levels compared to HC. Moreover, the changes in IL-17A over the treatment period were significantly associated with vitamin D changes (β=-0.04, SE=0.02, P=0.046). No difference in IL-17A, BAFF and vitamin D values was seen between patients with cirrhosis (n=14) and those without.

CONCLUSIONS

CHC patients with asymptomatic MC have increased levels of IL-17A and BAFF. IL-17A levels decline significantly while BAFF increases during treatment in responders. An interplay between IL-17A and vitamin D concentrations was revealed during the antiviral treatment.

Increased genomic instability following treatment with direct acting anti-hepatitis C virus drugs

Mixed Cryoglobulinemic Vasculitis (MCV) is a prominent extra-hepatic manifestation of Hepatitis C virus (HCV) infection. HCV has been reported to cause B-cell disorders and genomic instability. Here, we investigated B-cell activation and genome stability in HCV-MCV patients receiving the direct antiviral agent, Sofosbuvir, at multiple centers in Egypt. Clinical manifestations in HCV-MCV patients were improved at the end of treatment (EOT), such as purpura (100%), articular manifestations (75%) and neuropathy (68%). Eighteen patients (56%) showed vasculitis relapse after EOT. BAFF and APRIL were higher at EOT and continued to increase one year following treatment onset. Chromosomal breaks were elevated at EOT compared to baseline levels and were sustained at 3 and 6 months post treatment. We report increased expression of DNA genome stability transcripts such as topoisomerase 1 and TDP1 in HCV-MCV patients after treatment, which continued to increase at 12 months from treatment onset. This data suggest that B-cell activation and DNA damage are important determinants of HCV-MCV treatment outcomes.

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.

Rituximab as a front-line therapy for adult-onset minimal change disease with nephrotic syndrome

Minimal change disease (MCD) accounts for 15% of adult nephrotic syndrome (NS) cases. Adult-MCD patients may have more severe clinical features than pediatric patients. In children, Rituximab (RTX) has been used since 2006 to treat frequently relapsing NS. In adults, data about the efficacy of RTX for MCD are limited. We report our experience on the use of RTX in adult biopsy-proven MCD. Our series includes 6 adult patients (2 males and 4 females), age 45–73 years, treated with RTX (4 weekly doses of 375 mg/m²). Proteinuria decreased from 11,2 (23–4.8) g/24 hours to 0.6 (0–2) g/24 hours after 6 months, and to 0.4 (0–1, 4) g/24 h in the 4 pts with the longer follow-up. Creatinine decreased from 1.95 (0.5–5) mg/dl to 0.88 (0.6–1.3) mg/l. Five patients achieved a complete renal remission, while in 1 pt proteinuria decreased by 75%. RTX successfully depleted CD19 lymphocytes in 100% of pts for at least 6 months. No clinically relevant adverse events have been observed. This case series shows a remarkable efficacy of RTX in treatment of MCD. RTX can be an attractive alternative both in recurrent forms and in induction-therapy of MCD. RTX may be preferentially used in patients at a high risk of development of the adverse effects of corticosteroids and should be considered as an alternative option in patients with recurrent NS. Additional data are needed to inform clinical practice on how best to use RTX in this patient population, so that definitive randomized trials can be planned.

The European Vasculitis Society 2016 Meeting Report

The 2016 European Vasculitis Society (EUVAS) meeting, held in Leiden, the Netherlands, was centered around phenotypic subtyping in antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV). There were parallel meetings of the EUVAS petals, which here report on disease assessment; database; and long-term follow-up, registries, genetics, histology, biomarker studies, and clinical trials. Studies currently conducted will improve our ability to discriminate between different forms of vasculitis. In a project that involves the 10-year follow-up of AAV patients, we are working on retrieving data on patient and renal survival, relapse rate, the cumulative incidence of malignancies, and comorbidities. Across Europe, several vasculitis registries were developed covering over 10,000 registered patients. In the near future, these registries will facilitate clinical research in AAV on a scale hitherto unknown. Current studies on the genetic background of AAV will explore the potential prognostic significance of genetic markers and further refine genetic associations with distinct disease subsets. The histopathological classification of ANCA-associated glomerulonephritis is currently evaluated in light of data coming out of a large international validation study. In our continuous search for biomarkers to predict clinical outcome, promising new markers are important subjects of current research. Over the last 2 decades, a host of clinical trials have provided evidence for refinement of therapeutic regimens. We give an overview of clinical trials currently under development, and consider refractory vasculitis in detail. The goal of EUVAS is to stimulate ongoing research in clinical, serological, and histological management and techniques for patients with systemic vasculitis, with an outlook on the applicability for clinical trials.

Investigational drugs in systemic vasculitis

INTRODUCTION

Treatment of systemic vasculitis is based on glucocorticoids (GC) in association with immunosuppressive therapy. There are still unmet needs, including earlier onset of response, more targeted therapies, reduction of relapse-risk and decrease of long-term GC and classic immunosuppressants toxicities. Areas covered: In this review, we discuss investigational drugs in early phase clinical trials for induction of remission in vasculitis. We focus on ANCA-associated vasculitis, Behçet's disease, giant cell arteritis, Takayasu arteritis, and cryoglobulinemic vasculitis. We performed a comprehensive review of articles published on pubmed and a review of clinical trials registered online ( https://clinicaltrials.gov ) for each vasculitis. Expert opinion: Recent progress in the pathogenesis identifies new therapeutic targets. Some of these therapies are promising in GC sparing effects, in reducing relapse rate, and for their safety profile. These results need to be confirmed in large-scale phase III studies.