The prognosis of anti-glomerular basement membrane (anti-GBM) nephritis, often accompanied by the presence of antineutrophil cytoplasmic antibodies (ANCA), is poor, and even with aggressive therapeutic approaches, kidney replacement therapy (KRT) is typically required. Here, we present a case of necrotizing crescentic glomerulonephritis in a patient double-seropositive for anti-GBM antibodies and ANCA who successfully achieved dialysis independence following aggressive treatment, including avacopan. The patient was a 77-year-old woman with rapidly progressive glomerulonephritis and double seropositivity for myeloperoxidase-ANCA and anti-GBM antibodies. A kidney biopsy revealed diffuse cellular crescents with necrosis and immunoglobin (Ig)G1 and IgG3 positivity on immunofluorescence staining, leading to a histological diagnosis of anti-glomerular basement membrane nephritis. Our treatment approach involved a novel combination of glucocorticoids, rituximab, low-dose cyclophosphamide, and plasma exchange complemented by avacopan. Temporary hemodialysis was required, and the patient successfully discontinued dialysis after 12 sessions despite a poor histological prognosis. This case underscores the significance of considering aggressive therapeutic strategies, including avacopan, for severe anti-GBM nephritis, even in the absence of lung involvement, to avert the need for KRT.

Anti-glomerular basement membrane disease is a small-vessel vasculitis involving the kidneys (∼90%) and the lungs (∼60%). Antibodies against the glomerular basement membrane are directly pathogenic in anti-glomerular basement membrane disease; however, recent research has highlighted the critical role of T cells. Novel autoantigens within the glomerular basement membrane are also now recognized. Atypical forms of the disease are reported along with preceding triggers, such as immune checkpoint inhibitors, immunomodulatory drugs, and vaccines. Kidney outcomes in anti-glomerular basement membrane disease remain poor despite significant improvement in patient survival in the last 2 to 3 decades. Treatment typically relies on combined plasmapheresis with intensive immunosuppression. Dialysis dependency at presentation is a dominant predictor of kidney outcome. Histologically, a low (<10%) percentage of normal glomeruli, 100% crescents, together with dialysis dependency at presentation, is associated with poor kidney outcomes. In such cases, an individualized approach weighing the risks and benefits of treatment is recommended. There is a need for better ways to stop the toxic inflammatory activity associated with this disease. In this narrative review, we discuss recent updates on the pathogenesis and management of anti-glomerular basement membrane disease relevant to patients of all ages.

Goodpasture\'s syndrome (GPS) is a rare small vessel vasculitis characterized by circulating antibodies directed against the glomerular and alveolar basement membrane leading to renal and pulmonary manifestations. Here, we discuss a unique case of a 30-year-old Caucasian male smoker initially presenting with hemoptysis and anemia who was found to have biopsy-proven GPS with elevated anti-glomerular basement membrane (anti-GBM) antibodies. Unfortunately, the patient failed four months of standard treatment for GPS leading to end-stage renal disease (ESRD), while uniquely developing cardiorenal syndrome (CRS) with non-ischemic cardiomyopathy resulting in systolic and diastolic heart failure (HF). Despite aggressive medical management and hemodialysis, the patient\'s cardiac function continued to decline and the decision was made to insert an automatic implantable cardioverter defibrillator (AICD). To our knowledge, this is the first reported case of an anti-GBM-positive GPS patient who developed dilated cardiomyopathy. The importance of this report is to illustrate the rarity of developing CRS with non-ischemic cardiomyopathy and congestive heart failure from GPS and highlight the difficulty of determining management changes beyond guideline-directed medical therapy (GDMT) in GPS to slow the progression of worsening cardiac function.

The number of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV), anti-glomerular basement membrane (GBM) disease and double-positive patients (DPPs) following the coronavirus disease 2019 (COVID-19) vaccine reported in the literature is increasing, we reviewed the reported cases of AAV, anti-GBM disease and DPPs subsequent to COVID-19 vaccination, and compared the disparities in DPPs who received the COVID-19 vaccination and those who did not. We did not observe any differences in clinical phenotype of AAV, anti-GBM disease and DPPs before and after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination.

Successful induction of remission in anti-glomerular basement membrane (anti-GBM) glomerulonephritis can be obtained by using rituximab as a first-line immunosuppressive agent. We report the case of a 20-year-old male patient with Goodpasture\'s (anti-GBM) syndrome, with poor prognostic factors at presentation including intra-alveolar hemorrhage and dialysis-dependent rapidly progressive glomerulonephritis. The diagnosis was confirmed on kidney biopsy and serology (anti-GBM antibody titer). Rituximab was used as the first-line immunosuppressive agent in combination with pulse corticosteroids and plasmapheresis, to avoid potential side effects of cyclophosphamide. Anti-GBM antibody titers became undetectable after initiating rituximab. No adverse events were reported, and the patient became dialysis-independent after 6 months. This case reports the successful remission of a patient with Goodpasture\'s syndrome after induction with rituximab.

Short-chain fatty acids (SCFAs), as the link between gut microbiota and the immune system, had been reported to be protective in many autoimmune diseases by the modulation of T cell differentiation. The pathogenic role of autoreactive Th1 and Th17 cells and the protective role of Treg cells in the pathogenesis of anti-GBM disease have been fully demonstrated. Thus, the present study aimed to investigate the therapeutic effects of SCFAs in a rat model of anti-GBM disease.
Experimental anti-GBM disease was constructed by immunizing Wistar Kyoto rats with a nephrogenic T cell epitope α3127-148, and intervened by sodium acetate, sodium propionate, or sodium butyrate, 150 mM in the drinking water from day 0 to 42. Kidney injury was accessed by the biochemical analyzer, immunofluorescence, and immunohistochemistry. Antibody response was detected by ELISA. T cell clustering and proliferation were detected by flow cytometry. Human kidney 2 (HK2) cells were stimulated in vitro and cytokines were assessed by quantitative real-time PCR.
Treatment with sodium acetate, sodium propionate, or sodium butyrate ameliorated the severity of kidney impairment in rats with anti-GBM glomerulonephritis. In the sodium butyrate-treated rats, the urinary protein, serum creatinine, and blood urea nitrogen levels were significantly lower; the percentage of crescent formation in glomeruli was significantly reduced; and the kidneys showed reduced IgG deposition, complement activation, T cell, and macrophage infiltration as well as the level of circulating antibodies against anti-α3(IV)NC1. The treatment of sodium butyrate reduced the α3127-148-specific T cell activation and increased the Treg cells differentiation and the intestinal beneficial bacteria flora. It also alleviated the damage of HK2 cells treated with inflammatory factors and complement.
Treatment with SCFAs, especially butyrate, alleviated anti-GBM nephritis in rat model, indicating its potential therapeutic effects in clinical usage.

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.
Case series.
Patients identified by the French Nephropathology Group as having atypical anti-GBM nephritis between 2003 and 2022.
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.
Retrospective case series with a limited number of biopsies including electron microscopy.
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.
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.

Anti-glomerular basement membrane (Anti-GBM) disease is a severe form of glomerulonephritis (GN) that predominantly impacts individuals aged 20 to 70. It arises from the presence of circulating antibodies that specifically target an antigen inherent to the basement membranes of glomerular and alveolar structures. A unique subset within this category is termed atypical anti-GBM disease. In this variant, a distinctive feature is the widespread linear staining of the glomerular basement membrane (GBM) by IgG observed through immunofluorescence microscopy, with the notable absence of anti-GBM antibodies in the patient\'s serum. Here, we present an unusual case involving a 65-year-old female patient who sought medical attention due to rapidly progressing renal failure. The initial management included six hemodialysis sessions. Following a kidney biopsy, the diagnosis revealed a sclerosed phase of diffuse crescentic glomerulonephritis, attributed to atypical anti-GBM disease. Given the presence of diffuse crescents on the kidney biopsy, the medical team opted for an aggressive treatment regimen, commencing with intravenous methylprednisolone, followed by oral cyclophosphamide and oral prednisolone. Plasmapheresis was also recommended as part of the treatment plan, although it did not materialize due to the family\'s reluctance. Despite exhaustive efforts, the renal failure exhibited no signs of improvement, leading to the patient\'s discharge with a plan for ongoing maintenance hemodialysis. It is crucial to emphasize the pivotal role of immunosuppressive medications in managing this condition, as they play a critical role in preventing antibody formation and subsequent hypersynthesis that can exacerbate the disease.

We report the first case of relapsing anti-GBM disease secondary to alemtuzumab in a 24-year-old female with relapsing-remitting multiple sclerosis. Initial anti-GBM disease was detected 10 months after alemtuzumab was given and was diagnosed by demonstrating high anti-GBM antibody titers and with a confirmatory kidney biopsy. The patient presented with a rapidly progressive glomerulonephritis with no pulmonary involvement. After appropriate treatment, the patient went into remission with undetectable anti-GBM antibodies. However, 20 months later, the patient re-presented with relapsing anti-GBM disease. Despite aggressive treatment, the patient became dialysis-dependent.

Vasculitis and HIT have different etiologies, although both involve autoimmune mechanisms. Treatment of vasculitis often requires the use of an anticoagulant such as heparin, which can lead to the development of HIT and subsequent life-threatening complications. The analysis covered patients hospitalized in the Department of Internal Medicine, Nephrology and Dialysis in the period from September 2020 to March 2023. After analyzing the data, we selected four patients in whom vasculitis treatment was complicated by HIT. These included two patients with ANCA vasculitis and two patients with anti-GBM disease. We also described similar cases reported in the literature.