Management of mixed cryoglobulinemia with rituximab: evidence and consensus-based recommendations from the Italian Study Group of Cryoglobulinemia (GISC)

Paraprotein-Mediated Glomerular Diseases

Paraproteinemias are a group of complex diseases associated with an overproduction of a monoclonal immunoglobulin that can cause a diversity of kidney disorders and end-organ damage. In this review, we focus on paraprotein-mediated glomerular diseases. Kidney biopsy plays a crucial role in diagnosing these disorders, enabling the identification of specific histological patterns. These lesions are categorized into organized (such as amyloidosis, immunotactoid glomerulopathy, fibrillary glomerulonephritis, cryoglobulinemic glomerulonephritis, and monoclonal crystalline glomerulopathies) and nonorganized deposits (such as monoclonal Ig deposition disease and proliferative glomerulonephritis with monoclonal Ig deposits) based on the characteristics of immunofluorescence findings and the ultrastructural appearance of deposits on electron microscopy. This review aims to provide an update, highlight, and discuss clinicopathological aspects such as definition, epidemiology, clinical manifestations, mechanisms of kidney injury, histological features, and diagnostic procedures.

Understanding the relationship between HCV infection and progression of kidney disease

Hepatitis C virus (HCV) can cause a range of kidney diseases. HCV is the primary cause of mixed cryoglobulinaemia, which leads to cryoglobulinaemic vasculitis and cryoglobulinaemic glomerulonephritis (GN). Patients with acute cryoglobulinaemic vasculitis often exhibit acute kidney disease due to HCV infection, which typically progresses to acute kidney injury (AKI). HCV also increases the risk of chronic kidney disease (CKD) and the likelihood of developing end-stage renal disease (ESRD). Currently, direct-acting antiviral agents (DAAs) can be used to treat kidney disease at different stages. This review focuses on key findings regarding HCV and kidney disease, discusses the impact of DAAs, and highlights the need for further research and treatment.

Clinical characteristics, radiological features and outcomes in pulmonary involvement of cryoglobulinemia

BACKGROUND

Cryoglobulinemia with pulmonary involvement is rare, and its characteristics, radiological findings, and outcomes are still poorly understood.

METHODS

Ten patients with pulmonary involvement of 491 cryoglobulinemia patients at Peking Union Medical College Hospital were enrolled in this retrospective study. We analyzed the characteristics, radiological features and management of pulmonary involvement patients, and compared with those of non-pulmonary involvement with cryoglobulinemia.

RESULTS

The 10 patients with pulmonary involvement (2 males; median age, 53 years) included three patients with type I cryoglobulinemia and seven patients with mixed cryoglobulinemia. All of 10 patients were IgM isotype cryoglobulinemia. All type I patients were secondary to B-cell non-Hodgkin lymphoma. Four mixed patients were essential, and the remaining patients were secondary to infections (n = 2) and systemic lupus erythematosus (n = 1), respectively. Six patients had additional affected organs, including skin (60%), kidney (50%), peripheral nerves (30%), joints (20%), and heart (20%). The pulmonary symptoms included dyspnea (50%), dry cough (30%), chest tightness (30%), and hemoptysis (10%). Chest computed tomography (CT) showed diffuse ground-glass opacity (80%), nodules (40%), pleural effusions (30%), and reticulation (20%). Two patients experienced life-threatening diffuse alveolar hemorrhage. Five patients received corticosteroid-based regimens, and four received rituximab-based regimens. All patients on rituximab-based regimens achieved clinical remission. The estimated two-year overall survival (OS) was 40%. Patients with pulmonary involvement had significantly worse OS and progression-free survival than non-pulmonary involvement patients of cryoglobulinemia (P < 0.0001).

CONCLUSIONS

A diagnosis of pulmonary involvement should be highly suspected for patients with cryoglobulinemia and chest CT-indicated infiltrates without other explanations. Patients with pulmonary involvement had a poor prognosis. Rituximab-based treatment may improve the outcome.

Liver Disease-Associated Glomerulopathies

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infect a significant number of individuals globally and their extra-hepatic manifestations, including glomerular disease, are well established. Additionally, liver disease-associated IgA nephropathy is the leading cause of secondary IgA nephropathy with disease course varying from asymptomatic urinary abnormalities to progressive kidney injury. Herein we provide an updated review on the epidemiology, pathogenesis, clinical manifestations, and treatment of HBV- and HCV-related glomerulonephritis as well as IgA nephropathy in patients with liver disease. The most common HBV-related glomerulonephritis is membranous nephropathy, although membranoproliferative glomerulonephritis and podocytopathies have been described. The best described HCV-related glomerulonephritis is cryoglobulinemic glomerulonephritis occurring in about 30% of patients with mixed cryoglobulinemic vasculitis. The mainstay of treatment for HBV-GN and HCV-GN is antiviral therapy, with significant improvement in outcomes since the emergence of the direct-acting antivirals. However, cases with severe pathology and/or a more aggressive disease trajectory can be offered a course of immunosuppression, commonly anti-CD20 therapy, particularly in the case of cryoglobulinemic glomerulonephritis.

[Secondary vasculitides]

Vasculitides that occur in association with underlying primary diseases are called secondary vasculitides. In the diverse differential diagnostics of vasculitides, a large variety of secondary vasculitides have to be considered. Secondary vasculitides cover the full spectrum of vasculitides, presenting in manifold clinical manifestations. This article provides an overview of systemic diseases and etiological factors, such as infections, drugs, and malignancies, which can be associated with vasculitides. The possible associations with infectious agents are too numerous to be comprehensively covered and are discussed in an exemplary fashion and with a western European focus. Especially in atypical and refractory disease courses, a secondary vasculitis should be considered. In light of the diversity of differential diagnoses and the particular challenges posed by secondary vasculitides, interdisciplinary collaboration is the key for an accurate and early diagnosis as well as for successful treatment management. Treatment of the primary disease should always be prioritized and, if a drug-induced vasculitis is suspected, immediate cessation of the culprit drug is mandatory.

Cryoglobulinemic vasculitis: a 2023 update

PURPOSE OF REVIEW

Cryoglobulinemic vasculitis (CV) is an immune complex mediated small vessel vasculitis characterized by the presence of cryoglobulins in serum, often associated with hepatitis C infection, systemic autoimmune diseases or hematological conditions. The focus of this review is to provide an update on new insights into pathogenesis, epidemiology and therapies of infectious and noninfectious type II and type III CV.

RECENT FINDINGS

The introduction of new antiviral drugs for treatment of hepatitis C infection implied major changes in HCV-related CV, allowing to shed new lights on CV pathogenesis and mechanisms of relapse and, therefore, to increase the relevance of autoimmune diseases in CV epidemiology. Specific B-cell clones are involved in the production of pathogenic immune complexes that leads to small-vessel vasculitis. Therefore, both antiviral treatments [direct-acting antivirals (DAAs) and oral nucleot(s)ide analogues] and targeted anti-CD20 therapies (rituximab) prove to be safe and effective options, leading to a better prognosis. Association of Sjögren syndrome and CV defines a specific phenotype of patients, characterized by severe manifestations and poor outcome.

SUMMARY

Removing viral stimulation on B-cells through direct-acting antivirals and blocking B-cells proliferation and differentiation with rituximab are the goals of treatment of CV. However, further research is needed to identify prognostic factors of refractory and relapsing disease.

Hepatitis B virus-related cryoglobulinemia: Clinical characteristics, virological features, and treatment

BACKGROUND

Hepatitis B virus (HBV) infection is a rare etiology of cryoglobulinemia, and its clinical characteristics, virological features and treatment are poorly understood.

METHODS

This retrospective study enrolled 23 patients with HBV-related cryoglobulinemia from 497 cryoglobulinemia patients at Peking Union Medical College Hospital between January 2015 and February 2023. We analyzed the clinical characteristics, virological features and management of patients with HBV-related cryoglobulinemia.

RESULTS

The 23 patients (13 males; median age 48 years) were all mixed cryoglobulinemia and serological HBsAg positive, while 15 patients exhibited HBV-DNA replication. The presence of HBsAg in cryoglobulins was evaluated in 7 patients, all of whom were positive. The most commonly involved organs were kidneys (69.6%), skin (65.2%), peripheral nerves (21.7%), joints (8.7%), gastrointestinal tract (4.3%), and cardiac (4.3%). Eight patients received antiviral therapy with nucleot (s)ide analogues (NAs) alone, 12 patients received NA- and corticosteroid-based regimens, and 3 patients received NA- and rituximab-based regimens based on the severity of clinical symptoms. After a median follow-up of 44 months, four patients died, and one patient was lost to follow-up. All remaining patients (n = 18) achieved clinical remission, and HBV-DNA replication was not detected in 16 out of 18 patients. There was no HBV reactivation in patients treated with rituximab. The three-year overall survival and progression-free survival were 87.0% and 80.3%, respectively.

CONCLUSIONS

HBV-related cryoglobulinemia patients should be treated with antiviral therapy. Corticosteroids and rituximab are effective for severe cases, but patients need to be closely monitored for therapy-related infection.

Recent updates in the diagnosis and management of cryoglobulinemic vasculitis

INTRODUCTION

Cryoglobulinemic vasculitis (CV), also known as mixed cryoglobulinemic syndrome (MCS), is a systemic vasculitis that affects small blood vessels. It exhibits a wide range of clinical manifestations, making its treatment a continuing challenge for physicians.

AREAS COVERED

We conducted a comprehensive review to evaluate the current status of diagnosis, management, and treatment of mixed cryoglobulinemia (MC). The accurate clinical and serological evaluation plays a vital role in diagnosing MC, identifying potential comorbidities, and monitoring its main manifestations and complications. Treatment strategies should be individualized based on the underlying etiopathogenesis, the severity of organ involvement, and the associated underlying disease. At present, the two mainstays of CV treatment are direct antiviral agents (for HCV-related CV) and B-cell-targeted therapy.

EXPERT OPINION

MC remains one of the few autoimmune diseases where the etiology is known, at least for the majority of patients. Its pathogenetic mechanism offers a unique opportunity to investigate the interplay between infections and the immune system. Moving forward, the primary challenge will continue to lie in the treatment of resistant or refractory cases of CV, particularly those associated with autoimmune diseases, or cases classified as 'essential' CV.

Article Topic: Neuropathies Due to Infections and Antimicrobial Treatments

Purpose of eview

The aim of this review is to discuss the presentation, diagnosis, and management of polyneuropathy (PN) in selected infections. Overall, most infection related PNs are an indirect consequence of immune activation rather than a direct result of peripheral nerve infection,  Schwann cell infection, or toxin production, though note this review will describe infections that cause PN through all these mechanisms. Rather than dividing them by each infectious agent separately, we have grouped the infectious neuropathies according to their presenting phenotype, to serve as a guide to clinicians. Finally, toxic neuropathies related to antimicrobials are briefly summarized.

Recent findings

While PN from many infections is decreasing, increasing evidence links infections to variants of GBS. Incidence of neuropathies secondary to use of HIV therapy has decreased over the last few years.

Summary

In this manuscript, a general overview of the more common infectious causes of PN will be discussed, dividing them across clinical phenotypes: large- and small-fiber polyneuropathy, Guillain-Barré syndrome (GBS), mononeuritis multiplex, and autonomic neuropathy. Rare but important infectious causes are also discussed.