Clinicopathological characteristics of typical and atypical anti-glomerular basement membrane nephritis

Atypical Anti-Glomerular Basement Membrane Nephritis: A Case Series From the French Nephropathology Group

RATIONALE & OBJECTIVE

Atypical anti-glomerular basement membrane (GBM) nephritis is characterized by a bright linear immunoglobulin staining along the GBM by immunofluorescence without a diffuse crescentic glomerulonephritis nor serum anti-GBM antibodies by conventional enzyme-linked immunosorbent assay (ELISA). We characterized a series of patients with atypical anti-GBM disease.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

Patients identified by the French Nephropathology Group as having atypical anti-GBM nephritis between 2003 and 2022.

FINDINGS

Among 38 potential cases, 25 were included, of whom 14 (56%) were female and 23 (92%) had hematuria. The median serum creatinine at diagnosis was 150 (IQR, 102-203) μmol/L and median urine protein-creatinine ratio (UPCR) was 2.4 (IQR, 1.3-5.2) g/g. Nine patients (36%) had endocapillary proliferative glomerulonephritis (GN), 4 (16%) had mesangial proliferative GN, 4 (16%) had membranoproliferative GN, 2 (8%) had pure and focal crescentic GN, 1 (4%) had focal segmental glomerulosclerosis, and 5 had glomeruli that were unremarkable on histopathology. Nine patients (36%) had crescents, involving a median of 9% of glomeruli. Bright linear staining for IgG was seen in 22 cases (88%) and for IgA in 3 cases (12%). The 9 patients (38%) who had a monotypic staining pattern tended to be older with less proteinuria and rarely had crescents. Kidney survival rate at 1 year was 83% and did not appear to be associated with the light chain restriction.

LIMITATIONS

Retrospective case series with a limited number of biopsies including electron microscopy.

CONCLUSIONS

Compared with typical anti-GBM disease, atypical anti-GBM nephritis frequently presents with an endocapillary or mesangial proliferative glomerulonephritis pattern and appears to have a slower disease progression. Further studies are needed to fully characterize its pathophysiology and associated clinical outcomes.

PLAIN-LANGUAGE SUMMARY

Atypical anti-glomerular basement membrane (GBM) nephritis is characterized histologically by bright linear immunoglobulin staining along the GBM without diffuse crescentic glomerulonephritis or circulating anti-GBM antibodies. We report a case series of 25 atypical cases of anti-GBM nephritis in collaboration with the French Nephropathology Group. Compared with typical anti-GBM disease, we observed a slower disease progression. Patients frequently presented with heavy proteinuria and commonly had evidence of endocapillary or mesangial proliferative glomerulonephritis. About half of the patients displayed a monotypic immune staining pattern; they tended to be older, with less proteinuria, and commonly without glomerular crescents in biopsy specimens. No concomitant circulating monoclonal gammopathy was detected. Further studies are needed to fully characterize its pathophysiology and associated clinical outcomes.

Crescentic glomerulonephritis due to linear IgA anti-glomerular basement membrane disease: report of a rare case

Anti-glomerular basement membrane (GBM) disease is a rare and severe vasculitis that affects the glomerular and pulmonary capillaries and has an incidence of less than 2 cases per million individuals per year. Anti-GBM disease is mediated by autoantibodies against the α3 chain of type IV collagen. In the majority of cases, the autoantibodies are of the immunoglobulin G (IgG) class, with rare cases being mediated by immunoglobulin M (IgM) or immunoglobulin A (IgA); there are less than 15 IgA-mediated cases reported in the literature worldwide. The classic form of this disease manifests with rapidly progressive glomerulonephritis (RPGN), with or without pulmonary hemorrhage, and the diagnosis consists of identifying high titers of autoantibodies in the serum and/or deposited in the tissues. IgA antibodies are not identified in routine immunoassay tests, and renal biopsy with immunofluorescence is essential for diagnosis. We present a case of RPGN due to anti-GBM disease with linear IgA deposition, whose diagnosis was made exclusively by renal biopsy and with an unfavorable prognosis.

Systemic vasculitis involving the kidney: the nephropathologist's point of view

Kidneys are often targets of systemic vasculitis (SVs), being affected in many different forms and representing a possible sentinel of an underlying multi-organ condition. Renal biopsy still remains the gold standard for the identification, characterization and classification of these diseases, solving complex differential diagnosis thanks to the combined application of light microscopy (LM), immunofluorescence (IF) and electron microscopy (EM). Due to the progressively increasing complexity of renal vasculitis classification systems (e.g. pauci-immune vs immune complex related forms), a clinico-pathological approach is mandatory and adequate technical and interpretative expertise in nephropathology is required to ensure the best standard of care for our patients. In this complex background, the present review aims at summarising the current knowledge and challenges in the world of renal vasculitis, unveiling the potential role of the introduction of digital pathology in this setting, from the creation of hub-spoke networks to the future application of artificial intelligence (AI) tools to aid in the diagnostic and scoring/classification process.

Atypical Anti-Glomerular Basement Membrane Nephritis After the First Dose of the Severe Acute Respiratory Syndrome Coronavirus 2 mRNA Vaccine

Atypical anti-glomerular basement membrane (GBM) nephritis is a slowly progressive characterized by linear deposition of immunoglobulin (Ig) G in the GBM without circulating anti-GBM antibodies or lung involvement. There is no established therapy for this disease, and efficacy of the immunosuppressive treatment is questionable. A few cases of atypical anti-GBM nephritis have been reported after administration of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccine. Classic anti-GBM disease has also been reported after the administration of the second dose of the SARS-CoV-2 vaccine. Herein, we present the case of a SARS-CoV-2 vaccine-induced atypical anti-GBM nephritis that developed after the first dose and was unresponsive to immunosuppressive therapy. A 57-year-old Japanese woman developed edema 11 days after the first dose of the SARS-CoV-2 mRNA vaccine. She developed nephrotic-range proteinuria and microscopic hematuria. Renal biopsy revealed endocapillary proliferative glomerulonephritis with linear IgG deposition. However, electron-dense deposits were not detected on electron microscopy. The patient tested negative for circulating anti-GBM antibodies and was diagnosed with atypical anti-GBM nephritis. Although steroids and mizoribine were administered, the patient's renal function deteriorated. In conclusion, atypical anti-GBM nephritis may have earlier onset than the classic anti-GBM disease. Given its uncertainty of effectiveness, immunosuppressive agents should be carefully used for SARS-CoV-2 mRNA vaccine-induced atypical anti-GBM nephritis.

Anti-glomerular basement membrane vasculitis

Antiglomerular basement membrane disease (anti-GBM) is a rare life-threatening autoimmune vasculitis that involves small vessels and it is characterized by circulating autoantibodies directed against type IV collagen antigens expressed in glomerular and alveolar basement membrane. The typical clinical manifestations are the rapidly progressive glomerulonephritis and the alveolar hemorrhage. The diagnosis is usually confirmed by the detection of anti-GBM circulating antibodies. If not rapidly recognized, anti-GBM disease can lead to end stage kidney disease (ESKD). An early diagnosis and prompt treatment with immunosuppressive therapies and plasmapheresis are crucial to prevent a poor outcome. In this review, we discuss the primary form of anti-GBM (the so called Goodpasture syndrome) but also cases associated with other autoimmune diseases such as antineutrophil-cytoplasmic-antibody (ANCA) vasculitis, membranous nephropathy, IgA nephritis and systemic lupus erythematosus (SLE), as well as the few cases of anti-GBM vasculitis complicating kidney transplantation in the Alport syndrome.

Pediatric Glomerular Diseases in North India-Epidemiology and Clinicopathologic Correlation

Background

Glomerular diseases vary with age, and it is important to investigate the spectrum of glomerular diseases in pediatric patients to help in a more precise clinical diagnosis and optimize the management of patients. We aimed to study the clinicopathologic pattern of pediatric glomerular diseases in North India.

Methods

This is a 5-year retrospective, single-center cohort study. The database was searched to identify all pediatric patients with glomerular diseases in their native kidney biopsies.

Results

About 2890 native renal biopsies were studied, of which 409 were pediatric glomerular diseases. The median age was 15 years with a male preponderance. Nephrotic syndrome was the most common presentation (60.8%), followed by non-nephrotic proteinuria with hematuria (18.5%), rapidly proliferative glomerulonephritis (7%), isolated hematuria (5.3%), acute nephritic syndrome (3.4%), non-nephrotic proteinuria (1.9%), and advanced renal failure (0.7%). Minimal change disease (MCD) was the most common histological diagnosis, followed by focal segmental glomerulosclerosis (17.4%), IgA nephropathy (IgAN; 10%), membranous nephropathy (6.6%), lupus nephritis (5.9%), crescentic glomerulonephritis (2.9%), and C3 glomerulopathy (2.9%). Diffuse proliferative glomerulonephritis (DPGN) was the most common histological diagnosis in patients with hematuria and non-nephrotic as well as nephrotic range proteinuria. The most common histological diagnoses for isolated hematuria and acute nephritic syndrome were IgAN and postinfectious glomerulonephritis (PIGN), respectively.

Conclusions

MCD and lupus nephritis are the most common pediatric primary and secondary histopathologic diagnoses, respectively. The adolescent-onset glomerular diseases have a higher frequency of IgAN, membranous nephropathy, and DPGN. PIGN is still an important differential in our pediatric patients presenting with acute nephritic syndrome.

Granulomatosis With Polyangiitis Presenting as Complete Hearing Loss

Granulomatosis with Polyangiitis is a rare autoimmune vasculitis that is classically characterized by effects on the upper respiratory tract, lungs, and kidneys. Delay in diagnosis is often attributed to variable and sequential presentation of symptoms rather than concurrent symptomatology. It is important to recognize the wide range of initial presenting symptoms as early diagnosis and treatment is critical in preventing potentially irreversible damage resulting from delayed diagnosis. We present a case of a 29-year-old male with history of mixed sensorineural-conductive hearing loss presumed to be secondary to chronic otitis media who presented to the emergency department with complaint of hematemesis with a subsequent diagnosis of granulomatosis with polyangiitis. 

Anti-glomerular basement membrane disease with IgA nephropathy: A case report

BACKGROUND

Anti-glomerular basement membrane (GBM) disease is a rare autoimmune disease manifesting as acute progressive nephritis syndrome with or without varying degrees of pulmonary hemorrhage. Anti-GBM disease coexisting with Immunoglobulin A (IgA) nephropathy is rarer and has different clinical manifestations and prognoses than simple anti-GBM disease. We describe a case of coexistence of these two diseases.

CASE SUMMARY

A 49-year-old man with hematuria and proteinuria accompanied by a slight elevation of serum creatinine was admitted to our hospital. The pathological results of renal biopsy and the elevated serum anti-GBM antibody titer supported a diagnosis of anti-GBM disease combined with IgA nephropathy. After treatment with corticosteroids and cyclophosphamide, the patient's serum creatinine was relatively stable, and the hematuria and proteinuria moderately improved in the subsequent six months.

CONCLUSION

Anti-GBM disease coexisting with IgA nephropathy is rare. The clinical manifestations and prognosis are better than those of simple anti-GBM disease. In this case, the patient's condition was improved and his renal function remained relatively stable with corticosteroid and cyclophosphamide treatment. New detection methods to identify whether the crescents in this case were derived from anti-GBM disease or IgA nephropathy are worthy of further exploration.

Clinicopathological characteristics and predictors of poor outcome in anti-glomerular basement membrane disease - a fifteen year single center experience

Introduction

Anti-glomerular basement membrane (anti-GBM) disease is a small vessel vasculitis affecting the renal and lung capillary beds. We aim to study the clinicopathological characteristics and predictors of poor outcome of this disease in our population.

Materials and methods

This is a 15 year retrospective, single center observational study of Indian cohort. Patients with biopsy proven anti-GBM disease were studied.

Results

Anti-GBM disease was found in 0.5% of the total cases. The mean age at presentation was 46.7 years. Compared to renal limited disease those with pulmonary-renal syndrome had a higher frequency of hypertension, oliguria, percentage of crescents, interstitial inflammation and glomerulosclerosis. Double positive (anti-GBM and ANCA antibodies) patients showed more of glomerulosclerosis, tubular atrophy/interstitial fibrosis (IFTA) as well as periglomerular granulomas on biopsy. Patient survival at one year was 40.4% and death censored renal survival was 9.7%. Factors affecting the dialysis dependency at presentation were oligoanuria (p = .04), creatinine levels >5.7 mg/dl (p = .003), and high mean anti-GBM titers (p = .008). Atypical cases accounted for 8.3% of these patients. Oligoanuria (HR = 5.0, p = .05), high serum creatinine (HR = 1.55, p = .05), severe glomerulosclerosis (HR = 1.09, p = .03), and IFTA (HR = 2, p = .04) were associated with poor renal outcome. Advanced age (HR = 1.92, p = .03), high serum creatinine (HR = 1.9, p = .04) and high anti-GBM titers (HR = 1.01, p = .03) were associated with poor patient survival.

Conclusions

Anti-GBM is a rare disease with poor prognosis and varied presentations. Patients with pulmonary-renal syndrome showed severe disease whereas double positive had more of chronic changes. The predictors of poor prognosis include advanced age, oliguria, serum anti-GBM levels, serum creatinine levels, degree of glomerulosclerosis and IFTA. Atypical anti-GBM cases should be kept in mind while evaluating renal biopsies.

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.

Goodpasture's autoimmune disease - A collagen IV disorder

Goodpasture's (GP) disease is an autoimmune disorder characterized by the deposition of pathogenic autoantibodies in basement membranes of kidney and lung eliciting rapidly progressive glomerulonephritis and pulmonary hemorrhage. The principal autoantigen is the α345 network of collagen IV, which expression is restricted to target tissues. Recent discoveries include a key role of chloride and bromide for network assembly, a novel posttranslational modification of the antigen, a sulfilimine bond that crosslinks the antigen, and the mechanistic role of HLA in genetic susceptibility and resistance to GP disease. These advances provide further insights into molecular mechanisms of initiation and progression of GP disease and serve as a basis for developing of novel diagnostic tools and therapies for treatment of Goodpasture's disease.