Anti-glomerular basement membrane antibody disease treated with rituximab: A case-based review

Investigation of Clinical Features and Association between Vascular Endothelial Injury Markers and Cytomegalovirus Infection Associated with Thrombotic Microangiopathy in Patients with Anti-Neutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis: Case-Based Research

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) can occasionally trigger thrombotic microangiopathy (TMA). Cytomegalovirus (CMV) may be reactivated during intensive immunosuppressive therapy for AAV and cause TMA. Therefore, we aimed to evaluate the clinical features of and the association between vascular endothelial injury markers and TMA due to CMV in patients with AAV. A 61-year-old female was diagnosed with AAV and severe kidney injury. Immunosuppressive therapy gradually improved her symptoms and laboratory findings. However, 2 weeks after induction therapy initiation, she exhibited altered consciousness, a significant decrease in platelet count, and hemolytic anemia, resulting in a TMA diagnosis. Plasma exchange did not improve TMA findings and routine screening test revealed CMV infection. Ganciclovir injection improved the infection and TMA findings. Consequently, we diagnosed her with CMV-induced TMA. Both AAV and CMV may induce severe vascular endothelial injury, potentially leading to TMA development. CMV-induced TMA should be considered when TMA develops during induction therapy against AAV. Moreover, of the three serum markers of vascular injury-serum sulfatides, soluble thrombomodulin, and pentraxin 3-serum sulfatides may be associated with the development of TMA, and a high level of soluble thrombomodulin may be associated with the development of CMV viremia during the clinical course of AAV.

Goodpasture syndrome: a rare case presenting with recurrent haemoptysis

Goodpasture syndrome is a rare autoimmune disease which affects young adults with a male preponderance and can be triggered at any point in life with a classical clinical triad of rapidly progressive glomerulonephritis, diffuse pulmonary haemorrhage and circulating anti-glomerular basement membrane antibody (anti-GBM antibody). Here we are presenting a case of a young man with hypertension in his early 20s who presented with fatigue, recurrent haemoptysis, breathlessness and decreased urine output without features of infection. He was diagnosed at an early stage of the disease with the help of clinical, serological and radiological findings. An early diagnosis with effective treatment using plasma exchange, intravenous high-dose methylprednisolone, and cyclophosphamide showed a rapid improvement in the patient's condition with an immediate decrease in anti-GBM titres and proteinuria.

The Immunobiological Agents for Treatment of Antiglomerular Basement Membrane Disease

Combination therapy with glucocorticoids, cyclophosphamide, and plasmapheresis is recommended as the standard treatment for anti-glomerular basement membrane (anti-GBM) disease, but the prognosis of this disease remains poor. Several immunobiological agents have been administered or are expected to be useful for anti-GBM disease in light of refractory disease or the standard treatments' tolerability. Many data regarding the use of biologic agents for anti-GBM disease have accumulated, verifying the effectiveness and potential of biologic agents as a new treatment option for anti-GBM disease. Tumor necrosis factor (TNF) inhibitors were shown to be useful in animal studies, but these agents have no clinical use and were even shown to induce anti-GBM disease in several cases. Although the efficacy of the TNF-receptor antagonist has been observed in animal models, there are no published case reports of its clinical use. There are also no published reports of animal or clinical studies of anti-B-cell-activating factor, which is a member of the TNF family of agents. Anti-interleukin (IL)-6 antibodies have been demonstrated to have no effect on or to exacerbate nephritis in animal models. Anti-C5 inhibitor was observed to be useful in a few anti-GBM disease cases. Among the several immunobiological agents, only rituximab has been demonstrated to be useful in refractory or poor-tolerance patients or small uncontrolled studies. Rituximab is usually used in combination with steroids and plasma exchange and is used primarily as an alternative to cyclophosphamide, but there is insufficient evidence regarding the efficacy of rituximab for anti-GBM disease, and thus, randomized controlled studies are required.

Rituximab for the treatment of refractory anti-glomerular basement membrane disease

BACKGROUND

Anti-glomerular basement membrane (anti-GBM) disease is a rare but severe autoantibody-mediated immune disorder. The typical clinical presentation includes rapidly progressive glomerulonephritis and often concurrent pulmonary hemorrhage. The present study is aimed to investigate the therapeutic effects of rituximab either used alone or with other immunosuppressants.

METHODS

Eight patients diagnosed with anti-GBM disease and treated with rituximab from 2014 to 2020 were retrospectively reviewed.

RESULTS

Eight patients included 5 males and 3 females with a median age of 58.5 years. They all presented severe kidney injuries and 1 patient had lung hemorrhage. At diagnosis, the median of serum creatinine was 246 µmol/L (ranging from 91 to 850 µmol/L), with 3 patients requiring dialysis. All of them received corticosteroids and plasmapheresis. Rituximab was given as either standard four weekly doses or one pulse ranging from 100 to 600 mg. After a median follow-up of 34.5 months, kidney function was partially recovered or stabilized in 5/8 (62.5%) patients, free of dialysis. Anti-GBM antibodies remained undetected in all patients during follow-up. No severe adverse effect associated with rituximab was observed.

CONCLUSION

Rituximab may be an alternative therapy in the treatment of patient with severe or refractory anti-GBM disease.

Anti-glomerular basement membrane diseases and thrombotic microangiopathy treated with rituximab

A 68-year-old, male patient presented with a two-week history of malaise and anuria. Renal replacement therapy with hemodialysis was begun for acute kidney injury. His anti-glomerular basement membrane (anti-GBM) antibody titer was 3060 U/mL. Based on this finding, anti-GBM diseases was diagnosed. Plasmapheresis and high-dose glucocorticoid therapy were begun, but his hemolytic anemia and thrombocytopenia progressed. ADAMTS-13 activity decreased to 33%, but no inhibitor was detected. Secondary thrombotic microangiopathy (TMA) was suspected, and rituximab therapy was begun. The addition of rituximab is thought to have further reduced the anti-GBM antibodies, prevented recurrence, stabilized the platelet count, and facilitated the patient's withdrawal from plasmapheresis and glucocorticoid therapy. Rituximab may be a viable therapeutic option for anti-GBM diseases complicated with TMA.

ANCA-Associated Vasculitis With Anti-GBM Disease and Two Types of Tumors: A Case Report

Introduction

Anti-neutrophil cytoplasm antibody (ANCA)-associated-vasculitis and anti-glomerular basement membrane (GBM) disease are types of autoimmune diseases that are characterized by the presence of circulating autoantibodies. Most patients with these diseases experience sudden onset, rapid progress, and poor prognosis. The purpose of the present article is to report a case of ANCA-associated vasculitis with anti-GBM disease and two types of tumors.

Case Report

A 63-year-old Chinese woman who underwent resection for rectal cancer 6 years before and for lung adenocarcinoma 4 years before, presented with fever and nasal obstruction, for the past 2 months and chondritis of an ear for the past 1 month. The patient failed to respond to an anti-infection treatment at local and higher-level hospitals with the first episode of “recurrent sinusitis and fever.” Later, systemic symptoms such as fatigue, numbness of the limbs, and auricular chondritis gradually aggravated, followed by an increase in inconspicuous hematuria, proteinuria, and serum creatinine level. After admission, the GBM antibody, C-ANCA, and PR3 were positive. The renal puncture was diagnosed as anti-glomerular basement membrane antibody disease. After treatment, her serum creatinine decreased to 104 umol/l.

Discussion

In the present report, we introduced the case of a rare double-positive disease in a patient with two types of tumors. Importantly, we noted that colon cancer and lung cancer, PR3, and anti-GBM disease may be related to their pathogenesis and manifestations. Further research is warranted to confirm these hypotheses.

ANCA and anti-glomerular basement membrane double-positive patients: A systematic review of the literature

INTRODUCTION

Double-positive patients (DPP) exhibiting anti-glomerular basement membrane (GBM) and anti-neutrophil cytoplasmic antibodies (ANCAs) belong to an entity that is newly and poorly described, mainly in short series. We aimed to better characterize the epidemiological features, clinical presentation and therapeutic outcomes of these patients through a systematic review.

METHODS

We performed a systematic review of English-, German-, Spanish- and French-written publications from February 1987 to March 2020 reporting cases of DPP using the following databases: PubMed, Scielo, ScienceDirect, Google Scholar, The Cochrane Library, Open Grey, The Grey Literature Report, Clinicaltrials.gov and International Clinical Trial Registry Platform of the World Health Organization.

RESULTS

In total, 538 DPP were identified from 90 articles. Their clinical presentations were often severe, and the majority exhibited acute kidney failure (91.8%) with a median initial serum creatinine level of 873 μmol/L; 50.7% had alveolar haemorrhage. Other manifestations were present in 30.3% of DPP, mainly ear, nose, throat and articular manifestations. ANCAs were predominantly directed against MPO (n = 377/523; 72.1%) compared to PR3 (n = 107/523; 20.5%), with rare cases of triple positivity (n = 15/538; 2.9%). Although most patients received initial immunosuppressive therapy (n = 285/317; 89.9%), the one-year overall, renal and relapse-free survival rates were 64.8%, 38.7% and 71.1%, respectively.

CONCLUSION

DPP are associated with the characteristics of two eponymous vasculitis types, responsible for a poor overall and renal prognosis. Thus, simultaneous testing of both antibodies and systematic renal biopsy should be recommended in every patient with rapidly progressive glomerulonephritis to recognize this difficult-to-treat and rare disease.

IgA vasculitis and anti-GBM disease: two ends of a spectrum of immune complex vasculitis

Two immune complex vasculitides, IgA vasculitis (IgAV) and anti-GBM disease, represent polar extremes with regard to our understanding of disease pathogenesis, standardized management protocols and outcomes. This report compares our current approach to these uncommon entities in adults. Both diseases demonstrate degrees of small vessel necrosis and glomerular crescent formation. IgAV has an antibody response directed against unknown antigens, is often treated conservatively and has poorly studied long term renal outcomes. By contrast, anti-GBM disease presents with rapidly progressive glomerulonephritis and often results in end stage renal failure, despite intensive immunosuppression. Rarely, some cases of anti-GBM disease may be IgA predominant and bind other α-chains present in the GBM, but their clinical course is as for other anti-GBM disease patients but not IgAV, suggesting that the antigenic target rather than the antibody subclass is the critical factor in determining disease outcome. However, both conditions are associated with increased mortality in adults and result in significant chronic kidney disease and hypertension.

[Successful rituximab treatment of recurrent glomerulonephritis associated with antibodies against the glomerular basement membrane]

This article presents a case of recurrent anti-GBM disease (with antibodies against the glomerular basement membrane [GBM]) in a 17-year-old patient successfully treated with rituximab. Kidney biopsy with detection of linear deposition of immunoglobulin G (IgG) along the basement membrane is the diagnostic gold standard, which should be accompanied by serological testing. However, standard assays for the detection of anti-GBM antibodies have a high rate of false-negative results. In this particular case, an increase in proteinuria despite standard therapy (plasmapheresis, steroids, cyclophosphamide) was the clinical correlate of relapsing disease. The use of rituximab completely resolved the recurrent anti-GBM disease.

Use of Rituximab in Management of Rapidly Progressive Glomerulonephritis

Rapidly progressive glomerulonephritis (RPGN) is a form of glomerulonephritis characterized by loss of renal function within weeks. Although a variety of underlying causes can trigger RPGN, the ultimate pathologic mechanism is the podocyte and epithelial activation leading to the crescent formation. Rituximab has been increasingly and successfully used for autoimmune conditions in recent years. Treatment of RPGN is based on the underlying condition, but specific clinical guidelines are lacking. In this article, we have tried to establish the role of rituximab in the management of patients with RPGN. All the studies we have used were found in the PubMed database, limited to studies involving adults. Animal studies and studies involving the pediatric population were excluded. The currently available literature does not support switching to rituximab as the first-line agent. It has failed to prove consistently superior to other medications. However, combined with other commonly prescribed treatment regimens, namely corticosteroids, with or without cytotoxic drugs, rituximab has shown efficacy in many studies. Therefore, we have concluded that the most prudent use of rituximab in patients with RPGN would be in those with disease refractory to standard management with corticosteroids and cytotoxic drugs or in those who have intolerable side effects. We believe that clinicians should keep reporting any cases of RPGN treated with rituximab so that a more clear pattern emerges and more exact treatment guidelines can be made.

[ANCA and anti-MBG double-positive vasculitis: An update on the clinical and therapeutic specificities and comparison with the two eponymous vasculitis]

Double-positive vasculitis with anti-polynuclear cytoplasm (ANCA) and anti-glomerular basement membrane (GBM) antibodies is a rare entity of systemic vasculitis defined by the presence of ANCA and anti-GBM antibodies. The gradual accumulation of clinical and therapeutic data shows the usefulness of identifying and differentiating this entity from the two vasculitis respectively associated with the isolated presence of each of these two antibodies. Indeed, the double-positive ANCA and anti-GBM vasculitis appears to associate the characteristics of the demography and the extra-renal and pulmonary involvement of the ANCA-associated vasculitis on the one hand, and of the histological type and severe renal prognosis of the anti-MBG vasculitis on the other hand, with the renal involvement which is the only involvement consistently observed in double-positive vasculitis. The aim of this focus is to describe the epidemiological, clinico-biological, histological and prognostic characteristics of this entity, in light of recent literature and ongoing therapeutic changes in the two eponymous vasculitis.

Diagnostic and management challenges in Goodpasture's (anti-glomerular basement membrane) disease

Goodpasture's or anti-glomerular basement membrane (GBM) disease is classically characterized by the presence of circulating autoantibodies directed against the non-collagenous domain of the α3 chain of type IV collagen, targeting glomerular and alveolar basement membranes, and associated with rapidly progressive crescentic glomerulonephritis, with alveolar haemorrhage in over half the patients. However, there are increasing examples of variants or atypical presentations of this disease, and novel therapeutic options have been proposed, which nephrologists should be aware of. The pathophysiology of this condition has been understood through molecular analysis of the antibody-antigen interactions and the use of human leucocyte antigen-transgenic animals, while the association of anti-GBM antibodies with anti-neutrophil cytoplasm antibodies and their combined impact on disease phenotype is increasingly recognized, providing some insights into the basis of glomerular damage and autoimmunity.

Atypical Goodpasture's disease: a clinical case report and literature review

Goodpasture's disease (anti-GBM disease) is a rare small vessels vasculitis characterized by the presence of autoantibodies directed against the glomerular basement membrane (GBM) and alveolar basement membrane. Common feature of anti-GBM disease is a combination of rapidly progressive glomerulonephritis and alveolar hemorrhage (pulmonary-renal syndrome). We present a case of atypical disease course in a young male patient who developed alveolar hemorrhage without renal failure. The only symptom of renal involvement was isolated hematuria. Plasmapheresis combined with immunosuppression (cyclophosphamide and corticosteroids) was effective. We present a review of state-of-art data on the pathogenesis and disease course of anti-GBM disease.

Monotypic IgG1-kappa Atypical Anti-Glomerular Basement Membrane Nephritis: A Case Report

Anti-glomerular basement membrane (anti-GBM) glomerulonephritis is a rare disease caused by autoantibodies against the glomerular basement membrane. Atypical anti-GBM nephritis is clinically less aggressive and characterized by the absence of circulating autoantibodies to the basement membrane. A previously healthy 53-year-old white woman presented with a rising creatinine over a short observation period. Renal biopsy, urinary sediment, and laboratory testing confirmed the diagnosis of atypical anti-GBM disease. She received plasmapheresis, steroids, and cyclophosphamide. She developed hemorrhagic cystitis early in the treatment from oral cyclophosphamide and mycophenolate mofetil was substituted as a first-line drug. She responded favorably and continued on mycophenolate mofetil without evidence of relapse. Despite the absence of circulating autoantibodies, a diagnosis of atypical anti-GBM nephritis should not be excluded if a high index of clinical suspicion exists. Early renal biopsy should be considered. Mycophenolate mofetil may be a reasonable replacement for oral cyclophosphamide in the treatment of atypical anti-GBM disease when cyclophosphamide is contraindicated.

Use of rituximab as an induction therapy in anti-glomerular basement-membrane disease

BACKGROUND

Anti-glomerular basement-membrane (anti-GBM) disease (or Goodpasture disease) is characterized by severe kidney and lung involvement. Prognoses have improved with treatments that combine plasma exchange and immunosuppressive drugs. However, patients with severe renal involvement can have poor renal outcomes and cyclophosphamide can cause significant complications. Anti-GBM antibodies have a direct pathogenic effect on the disease: thus, therapeutics that can decrease their production, such as rituximab, could be a good alternative.

METHODS

The medical files of five patients that had received rituximab as a first-line therapy (instead of cyclophosphamide), plus plasma exchange and steroids, were reviewed. All patients had severe disease manifestations.

RESULTS

Four patients required dialysis at diagnosis and remained dialysis-dependent over the mean follow-up of 15 months. Three patients had pulmonary involvement, but recovered even though mechanical ventilation was required. Anti-GBM antibodies became rapidly undetectable in all patients. One infectious and two hematological complications were observed.

CONCLUSIONS

We report the outcomes of five patients with Goodpasture disease and treated with rituximab as a first-line treatment. This strategy was effective at treating pulmonary manifestations and was associated with a good biological response with no major serious adverse events. However, renal outcomes were not significantly improved.

Anti-Glomerular Basement Membrane Disease

Anti-glomerular basement membrane (anti-GBM) disease is a rare autoimmune small vessel vasculitis characterized by autoreactivity to antigens in type IV collagen chains expressed in glomerular and alveolar basement membrane. The detection of circulating anti-GBM antibodies, which are shown to be directly pathogenic, is central to disease diagnosis. Clinically, anti-GBM disease usually presents with rapidly progressive glomerulonephritis with or without alveolar hemorrhage. Rapid diagnosis and early treatment are required to prevent mortality and to preserve renal function. Relapse in anti-GBM disease is uncommon. Variant and atypical forms of anti-GBM disease are increasingly recognised.

Pulmonary vasculitis

Systemic vasculitides frequently affect the pulmonary vasculature. As the signs and symptoms of pulmonary vasculitis are variable and nonspecific, diagnosis and treatment represent a real challenge. Vasculitides should be given consideration, as these diseases present severe manifestations of rapidly progressing pulmonary disease. Examining other organs usually affected by vasculitides (e.g., the skin and kidneys) and determining autoantibody levels are essential to a better management of the disease. A radiological study would also contribute to establishing a diagnosis. The lungs are commonly involved in small-vessel vasculitis, anti-glomerular basement membrane disease, and vasculitides associated with antineutrophil cytoplasmic antibodies. Associated life-threatening diffuse alveolar haemorrhages and irreversible damage to other organs-usually the kidneys-are severe complications that require early diagnosis. Vasculitides are rare diseases that affect multiple organs. An increasing number of treatments-including biological agent-based therapies-requiring cooperation between specialists and centers have become available in the recent years. In the same way, clinicians should be familiar with the complications associated with immunosuppressive therapies.

Proliferative glomerulonephritis with linear immunoglobulin deposition: is this atypical antiglomerular basement membrane disease?

The antiglomerular basement membrane (anti-GBM) antibody disease is marked by the presence of specific antibodies against the non-collagenous domain of the type IV collagen's α3 chain. We describe a case of a 24-year-old Caucasian man, who may have had an atypical presentation of anti-GBM (slow progressive renal insufficiency, massive proteinuria and no detectable circulating anti-GBM antibody). The patient was treated with steroids and cyclophosphamide. This approach failed to attenuate the disease, and so rituximab was initiated with subsequent clinical improvement, normalisation of urinary sediment and marked regression of proteinuria; renal function remained stable. The renal biopsy immunofluorescence was crucial for the diagnosis.

Immunoadsorption in Anti-GBM Glomerulonephritis: Case Report in a Child and Literature Review

Antiglomerular basement membrane glomerulonephritis (anti-GBM GN) is a rare autoimmune disease that is characterized by rapidly progressive glomerulonephritis that may be associated with pulmonary hemorrhage. Anti-GBM GN is caused by autoantibodies (classically type G immunoglobulin) directed against the α3 subunit of type IV collagen. Without any appropriate treatment, the disease is generally fulminant, and patient and kidney survival is poor. The current guidelines recommend the use of plasma exchanges and immunosuppressive drugs. Immunoadsorption (IA) can remove pathogenic IgGs from the circulation and do not require plasma infusions, contrary to plasma exchanges. IA has seldom been used in adult patients with good tolerance and efficiency. We report herein the first pediatric case successfully treated with IA combined with immunosuppressive drugs in a 7-year-old girl who presented acute kidney injury (estimated glomerular filtration rate 38 mL/minute/1.73 m²). A kidney biopsy revealed numerous >80% glomerular crescents and linear IgG deposits along the glomerular basement membrane. Ten IA sessions led to rapid and sustained clearance of autoantibodies and improvement of kidney function until 21 months after onset (glomerular filtration rate 87 mL/minute/1.73 m²). No adverse effect was noted. This report adds to the growing body of evidence suggesting IA as a therapeutic alternative to plasma exchanges in anti-GBM GN. The other 27 published pediatric cases of anti-GBM GN are reviewed.

[Antiglomerular basement disease in children: Literature review and therapeutic options]

Antiglomerular basement membrane glomerulonephritis is a rare autoimmune disease characterized by rapidly progressive glomerulonephritis that may be associated with pulmonary hemorrhage (Goodpasture syndrome). The disease is caused by autoantibodies (classically IgGs) directed against the α3 subunit of type IV collagen. This is a rare disease in the adult population and extremely rare in children, with a reported cumulative annual incidence at 1/10⁶ people/year. Among scarce reported pediatric cases (n=31), most are girls (M/F sex ratio, 1:4), and the mean age at diagnoses is 9.2±4.6 years. A medical diagnosis is an emergency and is based on the identification of specific antibodies in the serum, and pathognomonic linear fixation of IgGs along the glomerular basement membrane. Without appropriate treatment, the disease is generally fulminant, and patient and kidney survival is poor. Indeed, glomerular function strongly correlates with histological lesions. The current guidelines recommend the use of plasma exchanges and immunosuppressive drugs. For the past few years, alternative therapeutics such as specific anti-B-cell antibodies (rituximab) or specific extrarenal cleansing such as immunoadsorption have been successfully used in adults. Immunoadsorptions (IAs) can remove pathogenic IgGs from the circulation and do not require plasma infusions, contrary to plasma exchanges. In this review, we discuss the key points of antiglomerular basement membrane glomerulonephritis diagnosis and conventional or alternative therapeutics.

Vasculitides and the Complement System: a Comprehensive Review

Systemic vasculitides are a group of rare diseases characterized by inflammation of the arterial or venous vessel wall, causing stenosis or thrombosis. Clinical symptoms may be limited to skin or to other organs or may include multiple manifestations as systemic conditions. The pathogenesis is related to the presence of leukocytes in the vessels and to the IC deposition, which implies the activation of the complement system (CS) and then the swelling and damage of vessel mural structures. The complement system (CS) is involved in the pathogenesis of several autoimmune diseases, including systemic vasculitides. This enzymatic system is a part of the innate immune system, and its function is linked to the modulation of the adaptive immunity and in bridging innate and adaptive responses. Its activation is also critical for the development of natural antibodies and T cell response and for the regulation of autoreactive B cells. Complement triggering contributes to inflammation-driven tissue injury, which occurs during the ischemia/reperfusion processes, vasculitides, nephritis, arthritis, and many others diseases. In systemic vasculitides, a group of uncommon diseases characterized by blood vessel inflammation, the contribution of CS in the development of inflammatory damage has been demonstrated. Treatment is mainly based on clinical manifestations and severity of organ involvement. Evidences on the efficacy of traditional immunosuppressive therapies have been collected as well as data from clinical trials that involve the modulation of the CS. In particular in small-medium-vessel vasculitides, the CS represents an attractive target. Herein, we reviewed the pathogenetic role of CS in these systemic vasculitides as urticarial vasculitis, ANCA-associated vasculitides, anti-glomerular basement membrane disease, cryoglobulinaemic vasculitides, Henoch-Schönlein purpura/IgA nephropathy, and Kawasaki disease and therefore its potential therapeutic use in this context.

Crescentic glomerulonephritis with dual positive anti-GBM and C-ANCA/PR3 antibodies

Antiglomerular basement membrane (anti-GBM) antibodies are more often accompanied by myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) than by proteinase 3 antineutrophil cytoplasmic antibody (PR3-ANCA). Both disease processes can affect the kidneys and/or the lungs. Patients with dual positive disease may have an atypical presentation which may delay diagnosis and treatment. Here we report a case of crescentic glomerulonephritis associated with positive PR3-ANCA and anti-GBM antibodies who underwent both lung and kidney biopsies.

Rituximab in anti-GBM disease: A retrospective study of 8 patients

OBJECTIVES

Anti-glomerular basement membrane (GBM) disease is a rare autoantibody-mediated disorder presenting as rapidly progressive glomerulonephritis, and often with pulmonary hemorrhage. Antibody removal with plasmapheresis and immunosuppressive drugs are the cornerstones of the treatment. Data regarding the use of specific B-cell depleting therapy such as rituximab are lacking.

METHODS

We conducted a retrospective observational study of 8 patients with severe and/or refractory GBM disease that received rituximab therapy.

RESULTS

Eight patients (2 men, 6 women) with a mean age of 26 ± 13.1 years old were included. Seven had severe renal involvement [median creatinin level was 282 μmol/l, range (65-423)] requiring high immunosuppressive or plasmapheresis dependent, and two had relapse of pulmonary hemorrhage including one with renal failure. Patients received an initial immunosuppressive treatment including steroid and cyclosphosphamide (n = 8) and plasmapheresis (n = 5). Except one late relapse, rituximab therapy was started within two months after diagnosis. All patients except one received 4 weekly dose of rituximab (375 mg(2)). Anti-GBM antibodies were still present in 6/8 patients, at rituximab initiation. Complete remission was observed in 7 out of 8 patients, mostly 3 months after rituximab therapy. After a mean follow-up of 25.6 months (range 4-93), patient and renal survival were 100% and 75% respectively, but rituximab use did not improve GFR. Anti-GBM antibodies remained negative for all patients during follow-up. Only one patient developed a severe bacterial infection but no opportunistic or viral infections were reported.

CONCLUSION

Rituximab may represent an additional and/or alternative therapy in the induction treatment of anti-GBM disease.

Pulmonary vasculitis

Pulmonary vasculitis encompasses inflammation in the pulmonary vasculature with involved vessels varying in caliber from large elastic arteries to capillaries. Small pulmonary capillaries are the vessels most commonly involved in vasculitis affecting the lung. The antineutrophil cytoplasmic antibody-associated vasculitides, which include granulomatosis with polyangiitis (formerly Wegener granulomatosis), microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome), are the small vessel vasculitides in which pulmonary vasculitis is most frequently observed and are the major focus of this review. Vasculitic involvement of the large pulmonary vessels as may occur in Behçet syndrome and Takayasu arteritis is also discussed.

What is new in the management of rapidly progressive glomerulonephritis?

Rapidly progressive glomerulonephritis (RPGN) results from severe crescentic damage to glomeruli and leads to irreversible kidney failure if not diagnosed and managed in a timely fashion. Traditional treatment has relied on glucocorticoids and cyclophosphamide, with additional plasmapheresis for certain conditions. Here we describe updates in the management of RPGN, according to the underlying renal pathology. However, there remains a paucity of trials that have enrolled patients with more advanced renal disease, dialysis dependence or with RPGN, and we are therefore still reliant on extrapolation of data from studies of patients with a less severe form of disease. In addition, reporting bias results in publication of cases or cohorts showing benefit for newer agents in advanced disease or RPGN, but it remains unclear how many unsuccessful outcomes in these circumstances take place. Since clinical trials specifically in RPGN are unlikely, use of biologic registries or combination of sufficient sized cohort series may provide indications of benefit outside of a clinical trial setting and should be encouraged, in order to provide some evidence for the efficacy of therapeutic regimens in RPGN and advanced renal disease.

A unique way to treat Goodpasture's disease

A 21-year-old man with no medical history presented to the emergency department with fatigue, oliguria and lower extremity oedema. Initial laboratory tests showed that the patient was in acute renal failure with a creatinine of 12.8 mg/dL (normal 0.51-1.18 mg/dL). Further work up showed crescentic glomerulonephritis on renal biopsy, and serology was positive for antiglomerular basement antibody (titre 191 U/mL, normal 0-0.7 U/mL). Shortly after diagnosis he developed haemoptysis and chest imaging was consistent with pulmonary haemorrhage. The standard immunotherapy for Goodpasture's disease is cyclophosphamide, but due to known reproductive toxicities associated with cyclophosphamide and the patient's age, it was decided to use alternate but less studied therapies for treatment. At discharge, the patient had undergone five plasmapheresis treatments, had received two doses of Rituximab with a steroid taper, and his antiglomerular basement membrane level had decreased significantly.

New biologics for glomerular disease on the horizon

The major advances achieved in immunology and cellular biology have led to the development of biotherapies that specifically target different mediators and pathways involved in the physiopathology of renal diseases. After the major breakthroughs obtained with B-cell depletion in autoantibody-mediated glomerulopathies, several other immunomodulation strategies are being tested in autoimmune glomerulonephritides, such as blockade of B-cell costimulation and activation, inhibition of complement pathways or modification of the T-B-lymphocyte crosstalk. Other drugs, inhibiting proinflammatory cytokines, are being developed in order to control the inflammatory response initiating and amplifying the kidney tissue injury observed in different systemic diseases. Finally, several promising therapeutic agents target specific renal cells such as podocytes or fibroblasts, blocking the common final steps of the deleterious pathological process underlying various types of nephropathy. Although several of these drugs are still under evaluation in phase 2/3 clinical trials, biotherapies have undoubtedly opened a new era in the treatment of glomerular disease.

Rituximab for the treatment of refractory simultaneous anti-glomerular basement membrane (anti-GBM) and membranous nephropathy

Antibody-mediated anti-glomerular basement membrane (anti-GBM) disease occurs rarely in the presence of another B-cell disorder, membranous nephropathy. The coexistence of these two autoimmune disorders would be anticipated to require differing, specific therapies targeted to each disease process. We describe a case of concomitant membranous nephropathy and anti-GBM disease in which conventional therapy, including steroids, plasmapheresis and cyclophosphamide, failed to attenuate the anti-GBM disease, yet responded to an alternative treatment of rituximab. This B-cell directed, monoclonal, chimeric antibody treatment substantially reduced anti-GBM antibody titers and led to discontinuation of plasmapheresis, while maintaining the remission of membranous nephropathy and anti-GBM disease.