Characteristics and outcome of Goodpasture's disease in children

Management dilemma of anti-GBM disease and p-ANCA-associated vasculitis with necrotizing skin lesions in a pediatric patient

Diffuse alveolar hemorrhage and acute glomerulonephritis characterize pulmonary-renal syndrome, in which anti-glomerular basement membrane antibodies (anti-GBM) and anti-neutrophil cytoplasmic antibodies (ANCA) are often assessed. The treatment is complex, requiring a multidisciplinary approach, based on immunosuppressant therapies, mechanical ventilation, plasma exchange (PLEX), and kidney replacement therapy. This clinical case describes a 7-year-old female hospitalized for edema, hypertension, and acute kidney failure. Laboratory tests showed the coexistence of ANCA and anti-GBM autoantibodies. A kidney biopsy revealed necrotizing crescentic glomerulonephritis with linear deposits of IgG along the GBM. Corticosteroids and cyclophosphamide, followed by rituximab and PLEX represented the therapeutical strategies. Hemodialysis was needed for the fluid overload and acute kidney injury (AKI) management. Posterior reversible leukoencephalopathy syndrome (PRES), hemorrhagic alveolitis, and cutaneous necrotizing skin lesions requiring the amputation of the limb complicated the clinical course, until the death of the patient. Early diagnosis and multidisciplinary and personalized therapies represent the management dilemmas for this disease. The evaluation of new treatments, such as avacopan and imlifidase, is much needed in pediatric-onset disease.

Efficacy and Safety of Rituximab in Antiglomerular Basement Membrane Disease

Introduction

Anti-glomerular basement membrane (GBM) disease is caused by pathogenic antibodies usually targeting the noncollagenous domain of the α3 chain of type IV collagen and frequently presents as rapidly progressive glomerulonephritis and diffuse alveolar hemorrhage (DAH). Rapid reduction of these antibodies is imperative for kidney survival and the mainstay of therapy is the combination of plasma exchange (PLEX), glucocorticoids, and cyclophosphamide. Rituximab has been postulated as a potential treatment for anti-GBM disease; however, data on efficacy and safety are lacking.

Methods

We performed a review of case reports and series (n = 28) providing individual patient-level data on the efficacy and safety of rituximab in adult and pediatric anti-GBM disease. In addition, we have received data from authors on 18 patients which stem from 4 studies that did not report on patient-level outcomes or were not previously reported. A search strategy of studies indexed in PubMed/MEDLINE was performed, followed by synthesis and analysis of the data.

Results

Sixty-seven patients [37 female (55%); 14 pediatric (21%); median age: 37 years] were followed-up with for a total of 87.1 person-years (median follow-up time: 9.5 months). They received rituximab as first-line (n = 39) or second-line (n = 28). Median serum creatinine was 416 μmol/l with 32 patients (48%) being dialysis-dependent at presentation and 24 (36%) having DAH. Intravenous pulse, oral glucocorticoids and PLEX were used in 85%, 98%, and 93%, respectively; and 54% of them received cyclophosphamide. Patients received a median of 4 (2-4) doses of rituximab with 11 patients (16%) having transient adverse effects. Patient survival was 91% and kidney survival was 67% (53% in adults and 71% in pediatric patients). Kidney survival was lower in initially dialysis-dependent patients (34% vs. 81%, P < 0.001). Patients receiving second-line rituximab had better kidney survival compared with those receiving it as first-line (73% vs. 46%, P = 0.03).

Conclusion

Acknowledging the limitations of our study, including publication and selection bias, rituximab had a favorable toxicity and efficacy profile. The results indicate that rituximab can be considered as a second-line therapy in anti-GBM disease when cyclophosphamide is contraindicated.

Outcome of rituximab treatment in children with non-dialysis-dependent anti-GBM disease

BACKGROUND

Anti-GBM disease is a rare vasculitis mediated by pathogenic antibodies against collagen IV. Anti-GBM disease presents with rapid progressive glomerulonephritis and leads to kidney failure if untreated. KDIGO recommends plasma exchanges (PEX) for antibody elimination and steroids plus cyclophosphamide (CTX) to suppress antibody production. CTX is associated with severe side effects including gonadal toxicity. Rituximab (RTX) and mycophenolate mofetil (MMF) might be a less toxic but equally efficient alternative to CTX. Studies in pediatric anti-GBM disease patients receiving RTX and MMF instead of CTX are lacking.

METHODS

A retrospective survey in 8 tertiary German centers was performed. The clinical data of patients diagnosed between 2014 and 2022 were collected and analyzed.

RESULTS

Five adolescent patients treated with PEX and RTX and/or MMF due to anti-GBM disease were analyzed. All patients had anti-GBM antibodies, hematuria, glomerular proteinuria, and pulmonary hemorrhage. eGFR was 124 ml/min/1.73 m2 (range 47-162), and all patients were non-dialysis-dependent but with relevant histological kidney affection (mean crescents on kidney biopsy 77%). Antibody clearance was achieved after 13 PEX cycles (range 6-31). Four out of 5 patients received methylprednisolone pulses. All patients received oral prednisolone and MMF, and four patients received a median of 4 RTX doses (range 2-4). After a mean follow-up of 27 months, 4/5 patients had conserved or improved kidney function, while one patient (20%) developed kidney failure.

CONCLUSIONS

In this small series of pediatric non-dialysis-dependent anti-GBM disease patients, first-line treatment with RTX and MMF showed a favorable kidney outcome in 4/5 cases and had an acceptable side effect profile.

Mitigated Clinical Course of Crescentic Glomerulonephritis with Positive Anti-Glomerular Basement Membrane Antibodies in a 14-Year-Old Girl

Introduction

Anti-glomerular basement membrane (anti-GBM) glomerulonephritis is associated with severe kidney failure and high morbidity and is exceedingly rare in children. The few pediatric studies published about this condition report dependency of kidney replacement therapy at presentation and partial or complete response in kidney function in a minority of cases.

Case Presentation

We describe the case of a 14-year-old girl with crescentic glomerulonephritis based on double positive anti-GBM and myeloperoxidase-antineutrophil cytoplasmic antibodies with a mitigated clinical course presenting with fatigue, anemia, and an estimated glomerular filtration rate range between 34 and 42 mL/min/1.73 m2. Response to treatment with daily therapeutic plasma exchanges, corticosteroids, and oral cyclophosphamide was prompt.

Conclusion

This ultrarare presentation highlights the need to consider determining anti-GBM antibodies and/or obtaining a kidney biopsy even in children with less severe presentations of unexplained glomerulonephritis and underlines the clinical treatment dilemma in this disease for children due to the potential long-term sequelae.

Anti-GBM Nephritis in an 11-Year-Old Female Child: A Rare Case Report

Anti-glomerular basement membrane (GBM) nephritis is a rare autoimmune condition involving the glomerular basement membrane of the kidneys. This case report describes an 11-year-old female who presented with edema, decreased urine output, and altered sensorium, progressing to hypertension and requiring emergent hemodialysis. A renal biopsy showing Immunoglobulin G (IgG) linear deposits confirmed the diagnosis. The patient was treated with intravenous methylprednisolone and antihypertensives and then scheduled for regular dialysis. This case underscores the critical need for early diagnosis and aggressive management to prevent severe complications in pediatric anti-GBM disease.

Glomerular Diseases Across Lifespan: Key Differences in Diagnostic and Therapeutic Approaches

Glomerular diseases are common causes of chronic kidney disease in childhood, adolescence, and adulthood. The epidemiology of glomerular diseases differs between different age groups, with minimal change disease being the leading cause of nephrotic syndrome in childhood, while membranous nephropathy and focal segmental glomerulosclerosis are more common in adulthood. IgA vasculitis is also more common in childhood. Moreover, there is a difference in disease severity with more children presenting with a relapsing form of nephrotic syndrome and a more acute presentation of antineutrophil cytoplasmic antibody-associated vasculitis and concomitant glomerulonephritis, as highlighted by the higher percentage of cellular crescents on kidney biopsy specimens in comparison with older patients. There is also a female preponderance in antineutrophil cytoplasmic antibody-associated vasculitis and more children present with tracheobroncholaryngeal disease. This article aims to summarize differences in the presentation of different glomerular diseases that are encountered commonly by pediatric and adult nephrologists and potential differences in the management.

Anti-glomerular basement membrane disease in children: a brief overview

Anti-glomerular basement membrane disease (Anti-GBM), previously known as Goodpasture syndrome, is an extremely rare cause of rapidly progressive glomerulonephritis and chronic kidney disease stage 5 (CKD5) in children. It is associated with acute pulmonary haemorrhage and it has a poor prognosis. It is classified as an autoimmune, small-vessel vasculitis caused by autoantibody formation against the alpha-3 chain in type IV collagen found in the glomerular basement membrane. Evidence of anti-GBM antibodies in serum or histologically are required for diagnosis. Treatment in children is based on very limited adult data and often involves the use of acute apheresis to rapidly remove circulating factors coupled with intensive immunosuppression such as cyclophosphamide and intravenous corticosteroids. There is also an emerging role for the use of biologic agents such as B cell depletion. The evidence base in children with anti-GBM disease is extremely limited. Multi-centre international collaboration is required to provide insight into this disease, better describe its prognosis and work towards improving outcomes. This review article summarises the key features of this disease in children, highlights treatment options and considers areas of unmet need.

Atypical Antiglomerular Basement Membrane Disease in a Pediatric Patient Successfully Treated with Rituximab

Classic antiglomerular basement membrane (anti-GBM) disease is an exceedingly rare but extremely aggressive form of glomerulonephritis, typically caused by autoantibodies directed against cryptic, conformational epitopes within the noncollagenous domain of the type IV collagen alpha-3 subunit. Pathologic diagnosis is established by the presence of strong, diffuse, linear staining for immunoglobulin on immunofluorescence microscopy. Recently, patients with atypical clinical and pathologic findings of anti-GBM disease have been described. These patients tend to have an indolent clinical course, without pulmonary involvement, and laboratory testing rarely reveals the presence of anti-GBM antibodies. Specific guidelines for the treatment and management of these patients are unclear. Here, we describe a case of atypical anti-GBM disease in a young child who presented with hematuria and prominent proteinuria. Throughout the course of his illness, creatinine remained normal. He was conservatively treated with steroids and rituximab, resulting in resolution of his clinical symptoms and normalization of laboratory findings.

Idiopathic Pulmonary Hemosiderosis as a Mimic of Pulmonary Vasculitis: A Case Report and Review of the Literature

PURPOSE OF REVIEW

Idiopathic pulmonary hemosiderosis (IPH) is one of the rarest and least understood causes of pulmonary hemorrhage in children. Illustrated by a complex case presentation, we discuss the clinical manifestations, diagnosis, pathology, proposed etiologies, and treatment of this rare disease. We also compare IPH with anti-glomerular basement membrane antibody syndrome (anti-GBM disease), another rare causes of pediatric pulmonary hemorrhage.

RECENT FINDINGS

Recent retrospective studies regarding IPH along with advanced immunotherapy have led to an improved understanding of how to best treat this condition, potential associations, and improved prognosis. Pathogenesis remains unknown, but several reports have suggested involvement of the alveolar capillary basement membrane. IPH is a poorly understood disease of unknown etiology that is a diagnosis of exclusion. Our patient was diagnosed with IPH after an exhaustive workup, including lung biopsy, into other immune-mediated causes of disease. While the pathogenesis of this rare disease remains elusive, our patient's immunofluorescent staining along the alveolar basement membrane without evidence of circulating antibody to type IV collagen raises the question of an immune-mediated pathogenesis of the disease with involvement of the alveolar basement membrane.

Maternal alloimmune IgG causes anti-glomerular basement membrane disease in perinatal transgenic mice that express human laminin α5

Mammalian immune systems are not mature until well after birth. However, transfer of maternal IgG to the fetus and newborn usually provides immunoprotection from infectious diseases. IgG transfer occurs before birth in humans across the placenta and continues after birth across the intestine in many mammalian species, including rodents. Transfer, which is mediated by the neonatal IgG Fc receptor, occurs by transcytosis across placental syncytiotrophoblasts and intestinal epithelium. Although maternal IgG is generally beneficial, harmful maternal allo- and autoantibodies can also be transferred to the fetus/infant, resulting in serious disease. To test this we generated transgenic mice that widely express human laminin α5 in their basement membranes. When huLAMA5 transgenic males were crossed with wild-type females, there was a maternal anti-human laminin α5 immune response. Maternal IgG alloantibody crossed the yolk sac and post-natal intestine invivo and bound in bright, linear patterns to kidney glomerular basement membranes of transgenic fetuses/neonates but not those of wild-type siblings. By postnatal day 18, most transgenic mice were proteinuric, had glomerular C3 deposits and inflammatory cell infiltrates, thickened and split glomerular basement membranes, and podocyte foot process effacement. Thus, our novel model of perinatal anti-glomerular basement membrane disease may prove useful for studying pediatric glomerulopathies, formation of the fetomaternal interface, and maternal alloimmunization.

Management and outcomes of childhood Goodpasture's disease

BackgroundIn an attempt to improve knowledge about childhood Goodpasture's disease, we performed a retrospective analysis of patients with Goodpasture's disease from several pediatric nephrology centers.MethodsWe analyzed the responses to 27 questions that elicited information about the following: incidence, demographics, patient history and clinical presentation, diagnostics performed, acute and chronic therapy, course of disease, and outcome.ResultsGoodpasture's disease, which is extremely rare in this age group, may manifest in 2-year-old toddlers and does not typically present with pulmonary findings before puberty. Goodpasture's disease has a poor outcome with more than 50% of patients progressing to end-stage renal disease. No deaths were reported in this cohort, and renal improvement was observed in children with severe biopsy findings who required renal replacement therapy during the acute phase.ConclusionThe present investigation gives detailed information about childhood Goodpasture's disease under real-life conditions and reveals that very few pediatric cases have been reported. Nearly 50% of children progressed to end-stage renal disease. However, long-term outcome in children might be better than in adults. Aggressive immunosuppressive therapy might be necessary for all affected children, even in patients who require renal replacement therapy or have severe biopsy findings.

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.

Basement membranes and autoimmune diseases

Basement membrane components are targets of autoimmune attack in diverse diseases that destroy kidneys, lungs, skin, mucous membranes, joints, and other organs in man. Epitopes on collagen and laminin, in particular, are targeted by autoantibodies and T cells in anti-glomerular basement membrane glomerulonephritis, Goodpasture's disease, rheumatoid arthritis, post-lung transplant bronchiolitis obliterans syndrome, and multiple autoimmune dermatoses. This review examines major diseases linked to basement membrane autoreactivity, with a focus on investigations in patients and animal models that advance our understanding of disease pathogenesis. Autoimmunity to glomerular basement membrane type IV is discussed in depth as a prototypic organ-specific autoimmune disease yielding novel insights into the complexity of anti-basement membrane immunity and the roles of genetic and environmental susceptibility.

Case report: anti-glomerular basement membrane antibody disease with normal renal function

Background

Anti-glomerular basement membrane (GBM) antibody disease is a rare autoimmune disorder characterized by rapidly progressive glomerulonephritis caused by autoantibodies against the α3-chain of type IV collagen in the GBM.

Case presentation

An 8-year-old girl with hematuria and proteinuria due to anti-GBM nephritis was diagnosed with hematuria and proteinuria during a school urine screening program. Her blood pressure and serum creatinine levels were normal. Her hematuria and proteinuria persisted for several months. Since a spot urine protein to creatinine ratio was around 7 g/g Cre, a percutaneous renal biopsy was performed. Immnofluorescent staining demonstrated a linear pattern for immunoglobulin G along the entire GBM. Chest computed tomography was normal. Anti-GBM antibody assays were reported as slightly raised; thus, the diagnosis was anti-GBM disease with normal renal function. Treatment included plasma exchange, intravenous high-dose methylprednisolone, and cyclophosphamide as a mainstay medication. The treatment was rapidly effective with an immediate decrease in anti-GBM titers and proteinuria.

Conclusions

Cases of anti-GBM disease with normal renal function in children are rare. Treatment in children has not been established; therefore, clinicians need to carefully select an effective treatment because the prognosis is poor.

Anti-GBM disease after nephrectomy for xanthogranulomatous pyelonephritis in a patient expressing HLA DR15 major histocompatibility antigens: a case report

Antiglomerular basement membrane (anti-GBM) antibody disease is uncommon in the pediatric population. There are no cases in the literature describing the development of anti-GBM disease following XGP or nephrectomy. We report the case of a 7-year-old boy with no past history of urological illness, treated with antimicrobials and nephrectomy for diffuse, unilateral xanthogranulomatous pyelonephritis (XGP). Renal function and ultrasound scan of the contralateral kidney postoperatively were normal. Three months later, the child represented in acute renal failure with rapidly progressive glomerulonephritis requiring hemodialysis. Renal biopsy showed severe crescentic glomerulonephritis with 95% of glomeruli demonstrating circumferential cellular crescents. Strong linear IgG staining of the glomerular basement membranes was present, in keeping with anti-GBM disease. Circulating anti-GBM antibodies were positive. Treatment with plasma exchange, methylprednisolone, and cyclophosphamide led to normalization of anti-GBM antibody titers. Frequency of hemodialysis was reduced as renal function improved, and he is currently independent of dialysis with estimated glomerular filtration rate 20.7 mls/min/1.73 m². Case studies in the adult literature have reported the development of a rapidly progressive anti-GBM antibody-induced glomerulonephritis following renal surgery where patients expressed HLA DR2/HLA DR15 major histocompatibility (MHC) antigens. Of note, our patient also expresses the HLA DR15 MHC antigen.

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.