Anti-glomerular basement membrane antibody disease in Japan: part of the nationwide rapidly progressive glomerulonephritis survey in Japan

Epidemiology, clinical features, risk factors, and outcomes in anti-glomerular basement membrane disease: A systematic review and meta-analysis

Anti-glomerular basement membrane (GBM) disease is a small-vessel vasculitis that represents the most aggressive form of autoimmune glomerulonephritis. The study aimed to investigate the prevalence, clinical characteristics, risk factors, and outcomes of anti-GBM disease through a systematic review and meta-analysis involving 47 studies with 2830 patients. The overall incidence of anti-GBM disease ranged from 0.60 to 1.79 per million population per annum. In rapidly progressive glomerulonephritis and crescentic glomerulonephritis, the pooled incidence rates were 8.0% and 12.8%, respectively. The pooled prevalence rates of anti-GBM antibodies, antineutrophil cytoplasmic antibodies (ANCA), and lung hemorrhage were 88.8%, 27.4%, and 32.6%, respectively. Patients with combined ANCA positivity demonstrated a prognosis comparable to those patients with only anti-GBM antibodies, though with differing clinical features. The pooled one-year patient and kidney survival rates were 76.2% and 30.2%, respectively. Kidney function on diagnosis and normal glomeruli percentage were identified as strong prognostic factors. This study represents the first comprehensive meta-analysis on anti-GBM disease, providing insights into its management. However, caution is warranted in interpreting some results due to the observational nature of the included studies and high heterogeneity.

Short-chain fatty acids ameliorate experimental anti-glomerular basement membrane disease

BACKGROUND

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.

MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSION

Treatment with SCFAs, especially butyrate, alleviated anti-GBM nephritis in rat model, indicating its potential therapeutic effects in clinical usage.

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.

Therapeutic plasma exchange for anti-glomerular basement membrane disease with dialysis-dependent kidney failure without diffuse alveolar hemorrhage

BACKGROUND

Anti-glomerular basement membrane (anti-GBM) disease is treated with immunosuppressive medications and plasma exchange. However, whether plasma exchange, in addition to pulse glucocorticoid therapy, would benefit patients with anti-GBM disease with dialysis-dependent kidney failure without diffuse alveolar hemorrhage remains unclear.

METHODS

Using the Japanese Diagnosis Procedure Combination database, we identified patients diagnosed with anti-GBM disease with dialysis-dependent kidney failure and without diffuse alveolar hemorrhage from July 2010 to March 2020. We compared in-hospital mortality within 10 days of hospitalization between patients who received therapeutic plasma exchange in addition to pulse glucocorticoid therapy and those who received pulse glucocorticoid therapy alone. Overlap weighting based on propensity score was performed to adjust for potential confounders.

RESULTS

We identified 207 eligible patients; 168 patients received therapeutic plasma exchange plus pulse glucocorticoid therapy, while 39 patients received pulse glucocorticoid therapy alone. The mean dose of therapeutic plasma exchange was 52.2 ml/kg/day of albumin and/or fresh frozen plasma. Therapeutic plasma exchange in addition to pulse glucocorticoid therapy was associated with a lower in-hospital mortality risk in the unweighted (10.7% versus 28.2%; risk difference, 17.5%; 95% confidence interval, 2.6-32.4%; P = 0.02) and weighted analyses (11.5% versus 28.4%; risk difference, 17.0%; 95% confidence interval, 1.5-32.5%; P = 0.03) than pulse glucocorticoid therapy alone.

CONCLUSIONS

This retrospective cohort study using a national database suggests that therapeutic plasma exchange may improve the in-hospital prognosis of anti-GBM disease with dialysis-dependent kidney failure and without diffuse alveolar hemorrhage.

Case Report: Coexistence of Anti-Glomerular Basement Membrane Disease, Membranous Nephropathy, and IgA Nephropathy in a Female PatientWith Preserved Renal Function

The coexistence of anti-glomerular basement membrane (GBM) disease, idiopathic membranous nephropathy (IMN), and IgA nephropathy in one patient is a very rare case, which has not yet been reported. Whether the three diseases are correlated and the underlying mechanism remain unknown. Herein, we report a 48-year-old female patient that was admitted because of proteinuria and abnormal renal function, which was diagnosed as anti-GBM disease, idiopathic membranous nephropathy, and IgA nephropathy by renal biopsy. The patient received treatment including high-dose methylprednisolone pulse therapy, plasma exchange, and intravenous infusion of both cyclophosphamide (CTX) and rituximab. In the follow-up, the titer of the anti-GBM antibody gradually decreased, renal function was restored, and urinary protein was reduced, without significant adverse effects.

Technology status and trends of industrial wastewater treatment: A patent analysis

Globally, 80% of wastewater, among which 28% came from industry, returned to the ecosystem without treatment or reuse. The discharge of industrial wastewater poses public health and environmental concerns. The necessity and urgency of industrial wastewater treatment (IWT) will bring great challenges to most countries. This paper conducted the patent analysis combined with text mining to quantitatively analyze 11,840 patents related to IWT in the Derwent Innovations Index database. The results showed that: From 1973 to 2020, the number of patents related to IWT annually was increasing consistently. China ranked first in the number of patent publications. In contrast, the United States and some patent organizations, such as World Intellectual Property Organization, produced fewer patents, while they played more important roles in knowledge transfer. The core technology analysis suggested that method, device, material and related industry were hot topics. From activated sludge treatment technology, industrial wastewater treatment technology had gone through a development process from single technology treatment to combined technologies treatment. In the foreseeable future, research on devices for physical treatment, advanced oxidation processes, automated and energy-saving treatment systems were the promising directions.

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.

Anti-glomerular Basement Membrane Glomerulonephritis During the First Trimester of Pregnancy

A 28-year-old woman was admitted during the eighth week of her pregnancy because her clinical course was consistent with rapid progressive glomerulonephritis (RPGN). Anti-glomerular basement membrane antibody (anti-GBM Ab) and myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) were positive, and the anti-GBM Ab titer being extremely high. She was treated with hemodialysis, plasma exchange and prednisolone. She survived the illness; however, neither the fetus nor her kidney function could be rescued. She had human leukocyte antigen (HLA)-DRB1*1502:01, which differs from the DRB1*1501 associated with anti-GBM GN. When patients have particular symptoms, we should check the urine and serum creatinine to exclude RPGN, even in cases of pregnancy.

Clinical and immunologic characteristics of Japanese patients with anti-glomerular basement membrane disease: case reports and literature review

Background

Clinical studies of anti-glomerular basement membrane (GBM) disease were limited because of the low incidence. We aimed to report the characteristics, treatments, and outcomes of patients with anti-GBM disease at a tertiary reference medical center in Japan and review the literature of mortality in patients with anti-GBM disease.

Case presentation

Case 1 was a 72-year-old Japanese man that was referred with worsening of the serum creatinine (from 1.1 to 27.3 mg/dL). Anti-GBM disease was confirmed by renal biopsy, and treatments with oral prednisolone and plasmapheresis were initiated. Although his anti-GBM antibody decreased (from 476 to 18 units/mL) after the treatments, the patient died from lung abscess. Case 2 was a 32-year-old Japanese man that presented with fever and macroscopic hematuria. At presentation, his serum creatinine was 4.2 mg/dL, and anti-GBM antibody was 265 units/mL. Renal biopsy confirmed the diagnosis of anti-GBM disease, and intensive treatments with plasmapheresis and methyl prednisolone were started, followed by oral prednisolone. Living-donor kidney transplantation was performed because his anti-GBM antibody had remained undetectable for 1 year after diagnosis. In the main text, clinicopathological characteristics of 12 patients with anti-GBM disease at our institution were summarized.

Conclusions

We found that the 1-year survival rate of patients with anti-GBM disease was 88% in our cohort, which was comparable to previous studies. Multicenter, nationwide studies are expected to evaluate prognosis of Japanese patients with this rare entity.

Impact of ANCA-Associated Vasculitis on Outcomes of Hospitalizations for Goodpasture's Syndrome in the United States: Nationwide Inpatient Sample 2003-2014

Background and objectives: Goodpasture’s syndrome (GS) is a rare, life-threatening autoimmune disease. Although the coexistence of anti-neutrophil cytoplasmic antibody (ANCA) with Goodpasture’s syndrome has been recognized, the impacts of ANCA vasculitis on mortality and resource utilization among patients with GS are unclear. Materials and Methods: We used the National Inpatient Sample to identify hospitalized patients with a principal diagnosis of GS from 2003 to 2014 in the database. The predictor of interest was the presence of ANCA-associated vasculitis. We tested the differences concerning in-hospital treatment and outcomes between GS patients with and without ANCA-associated vasculitis using logistic regression analysis with adjustment for other clinical characteristics. Results: A total of 964 patients were primarily admitted to hospital for GS. Of these, 84 (8.7%) had a concurrent diagnosis of ANCA-associated vasculitis. Hemoptysis was more prevalent in GS patients with ANCA-associated vasculitis. During hospitalization, GS patients with ANCA-associated required non-significantly more mechanical ventilation and non-invasive ventilation support, but non-significantly less renal replacement therapy and plasmapheresis than those with GS alone. There was no significant difference in in-hospital outcomes, including organ failure and mortality, between GS patients with and without ANCA-associated vasculitis. Conclusions: Our study demonstrated no significant differences between resource utilization and in-hospital mortality among hospitalized patients with coexistence of ANCA vasculitis and GS, compared to those with GS alone.

Molecular Analysis of Goodpasture's Disease Following Hematopoietic Stem Cell Transplant in a Pediatric Patient, Recalls the Conformeropathy of Wild-Type Anti-GBM Disease

Background: Goodpasture's disease (GP) is mediated by autoantibodies that bind the glomerular and alveolar basement membrane, causing rapidly progressive glomerulonephritis with or without pulmonary hemorrhage. The autoantibodies bind neoepitopes formed upon disruption of the quaternary structure of α345NC1 hexamer, a critical structural domain of α345 collagen IV scaffolds. Hexamer disruption leads to a conformational changes that transitions α3 and α5NC1 subunits into immunogens, however, the trigger remains unknown. This contrasts with another anti-GBM disease, Alports' post-transplant nephritis (APTN), where the pathogenic alloantibody binds directly to native NC1 hexamer. The current report includes the first study of antigenic specificity and allo-incompatability in anti-GBM disease occurring after allogeneic haematopoietic stem cell transplant (HSCT).

Results: The anti-GBM antibodies were found to be directed predominantly against the E_A epitope of the α3 NC1 monomer of collagen IV and developed rapidly in patient serum reaching peak level within 5 weeks. Autoantibody binding to native α345NC1 hexamer was minimal; however, binding was greatly increased upon dissociation of the native hexamer. There were no polymorphic genetic differences between donor and recipient collagen IV genes which would be predicted to cause a significant NC1 conformational change or to provide a target for antibody binding. Both patient and donor possessed the Goodpasture's susceptibility HLA-allele DRB1^*1501.

Conclusions: The current report includes the first in-depth study of allo-incompatability and antigenic specificity in anti-GBM disease occurring after allogeneic haematopoietic stem cell transplant (HSCT). No polymorphic genetic differences were identified between donor and recipient collagen IV genes which would be predicted to provide a target for antibody binding. Furthermore, autoantibody binding to native α345NC1 hexamer was minimal, increasing greatly upon dissociation of the native hexamer, resembling wild-type GP diseases and marking this as the first example of a post-HSCT conformeropathy.

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.

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.

Coexistence of Anti-Glomerular Basement Membrane Glomerulonephritis and Membranous Nephropathy in a Female Patient with Preserved Renal Function

Renal prognosis for anti-glomerular basement membrane (GBM) glomerulonephritis is poor. The greater the amount of anti-GBM antibody binding the antigen (type IV collagen of the glomerular basement membrane), the greater the number of crescents that develop in glomeruli, resulting in progression of renal impairment. Immunofluorescence staining reveals linear IgG depositions on glomerular capillary walls. Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome in middle-aged to elderly patients. Immune complex is deposited in the sub-epithelial space of the glomerulus resulting in the development of a membranous lesion. Immunofluorescence staining reveals granular IgG depositions on glomerular capillary walls. Coexisting anti-GBM glomerulonephritis and MN are rare and, here we report a case of coexisting anti-GBM glomerulonephritis and MN with preserved renal function. There are some cases of coexisting anti-GBM glomerulonephritis and MN do not show severely decreased renal function. A 76-year-old Japanese woman presented with nephrotic syndrome, microscopic hematuria, and was positive for anti-GBM antibody. Kidney biopsy revealed linear and granular IgG depositions in glomerular capillary walls, crescent formations, and electron-dense deposits in the sub-epithelial space. She was diagnosed with anti-GBM glomerulonephritis and MN. Steroid and cyclosporine therapy achieved complete remission, and kidney function was preserved. In conclusion, coexisting anti-GBM glomerulonephritis and MN can have preserved renal function. IgG subclass of deposited anti-GBM antibody may be associated with the severity of anti-GBM glomerulonephritis. In addition, in the case of nephrotic syndrome with hematuria, we should consider the possibility of coexisting anti-GBM glomerulonephritis and MN.

Unusual Case of Posterior Reversible Encephalopathy Syndrome in a Patient with Anti-glomerular Basement Membrane Antibody Glomerulonephritis: A Case Report and Review of the Literature

Posterior reversible encephalopathy syndrome (PRES) is characterized by a clinical and radiological entity with the sudden onset of seizures, headache, altered consciousness, and visual disturbances in patients with the findings of reversible vasogenic subcortical edema without infarction. Hypertension, renal disease, and autoimmune disease are co-morbid conditions of PRES. Nevertheless, there have only been a few case reports of PRES in a patient with anti-glomerular basement membrane antibody glomerulonephritis (anti-GBM GN). This paper presents the possible first Korean case of a 36-year-old woman with the striking features of PRES. She presented with a sudden onset of visual blindness, headache, and seizure. The brain MRI images revealed hyperintense lesions in both the occipital and parietal lobes, which suggested vasogenic edema. Three months before this presentation, she was diagnosed with anti-GBM GN. Since then, she underwent immunosuppression with cyclophosphamide and steroid, and hemodialysis for renal failure with a treatment of anti-GBM GN.

Effectiveness of Plasmapheresis in a Patient with Anti-glomerular Basement Membrane Antibody Glomerulonephritis with Advanced Kidney Dysfunction

Patients with anti-glomerular basement membrane antibody glomerulonephritis (anti-GBM GN) have severe kidney dysfunction, leading to end-stage renal disease. The effect of plasmapheresis and immunosuppressive treatment in patients with severe glomerular changes is controversial. A 62-year-old man was admitted with rapidly progressive glomerulonephritis and diagnosed with anti-GBM GN. He required hemodialysis. All glomeruli in the kidney biopsy specimen had cellular crescents without fibrotic changes, suggesting reversible damage. He was treated with plasmapheresis until the anti-glomerular basement membrane antibodies disappeared. His kidney function recovered, and dialysis was able to be discontinued. Frequent plasmapheresis in patients with dialysis-dependent anti-GBM GN may improve the kidney prognosis.

Anti-Glomerular Basement Membrane Disease

Anti-glomerular basement membrane (anti-GBM) disease is a rare small vessel vasculitis that affects the capillary beds of the kidneys and lungs. It is an archetypic autoimmune disease, caused by the development of directly pathogenic autoantibodies targeting a well characterized autoantigen expressed in the basement membranes of these organs, although the inciting events that induce the autoimmune response are not fully understood. The recent confirmation of spatial and temporal clustering of cases suggests that environmental factors, including infection, may trigger disease in genetically susceptible individuals. The majority of patients develop widespread glomerular crescent formation, presenting with features of rapidly progressive GN, and 40%-60% will have concurrent alveolar hemorrhage. Treatment aims to rapidly remove pathogenic autoantibody, typically with the use of plasma exchange, along with steroids and cytotoxic therapy to prevent ongoing autoantibody production and tissue inflammation. Retrospective cohort studies suggest that when this combination of treatment is started early, the majority of patients will have good renal outcome, although presentation with oligoanuria, a high proportion of glomerular crescents, or kidney failure requiring dialysis augur badly for renal prognosis. Relapse and recurrent disease after kidney transplantation are both uncommon, although de novo anti-GBM disease after transplantation for Alport syndrome is a recognized phenomenon. Copresentation with other kidney diseases such as ANCA-associated vasculitis and membranous nephropathy seems to occur at a higher frequency than would be expected by chance alone, and in addition atypical presentations of anti-GBM disease are increasingly reported. These observations highlight the need for future work to further delineate the immunopathogenic mechanisms of anti-GBM disease, and how to better refine and improve treatments, particularly for patients presenting with adverse prognostic factors.

Pre-existing chronic interstitial pneumonia is a poor prognostic factor of Goodpasture's syndrome: a case report and review of the literature

BACKGROUND

Goodpasture's syndrome is a rare disease that is characterized by rapidly progressive glomerulonephritis and diffuse alveolar hemorrhage.

CASE PRESENTATION

A 71-year-old Japanese man who had chronic interstitial pneumonia was diagnosed as having Goodpasture's syndrome. Both anti-glomerular basement membrane antibody and myeloperoxidase anti-neutrophil cytoplasmic antibody were increased. Despite intensive treatments, including mechanical ventilation, he died from respiratory failure. Pathological findings at autopsy showed rapidly progressive glomerulonephritis in his kidneys, diffuse alveolar hemorrhage, hyaline membranes, and fibroblastic foci in his lungs. The cause of death was diagnosed as respiratory failure as a result of diffuse alveolar damage induced by a combination of diffuse alveolar hemorrhage and exacerbation of interstitial pneumonia.

CONCLUSIONS

We report a case of Goodpasture's syndrome complicated with pre-existing chronic interstitial pneumonia and positive myeloperoxidase anti-neutrophil cytoplasmic antibody. We reviewed six similar cases reported in the literature and concluded that Goodpasture's syndrome with pre-existing interstitial pneumonia and myeloperoxidase anti-neutrophil cytoplasmic antibody is related to a poor prognosis.

Spatial and Temporal Clustering of Anti-Glomerular Basement Membrane Disease

BACKGROUND AND OBJECTIVES

An environmental trigger has been proposed as an inciting factor in the development of anti-GBM disease. This multicenter, observational study sought to define the national incidence of anti-GBM disease during an 11-year period (2003-2014) in Ireland, investigate clustering of cases in time and space, and assess the effect of spatial variability in incidence on outcome.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We ascertained cases by screening immunology laboratories for instances of positivity for anti-GBM antibody and the national renal histopathology registry for biopsy-proven cases. The population at risk was defined from national census data. We used a variable-window scan statistic to detect temporal clustering. A Bayesian spatial model was used to calculate standardized incidence ratios (SIRs) for each of the 26 counties.

RESULTS

Seventy-nine cases were included. National incidence was 1.64 (95% confidence interval [95% CI], 0.82 to 3.35) per million population per year. A temporal cluster (n=10) was identified during a 3-month period; six cases were resident in four rural counties in the southeast. Spatial analysis revealed wide regional variation in SIRs and a cluster (n=7) in the northwest (SIR, 1.71; 95% CI, 1.02 to 3.06). There were 29 deaths and 57 cases of ESRD during a mean follow-up of 2.9 years. Greater distance from diagnosis site to treating center, stratified by median distance traveled, did not significantly affect patient (hazard ratio, 1.80; 95% CI, 0.87 to 3.77) or renal (hazard ratio, 0.76; 95% CI, 0.40 to 1.13) survival.

CONCLUSIONS

To our knowledge, this is the first study to report national incidence rates of anti-GBM disease and formally investigate patterns of incidence. Clustering of cases in time and space supports the hypothesis of an environmental trigger for disease onset. The substantial variability in regional incidence highlights the need for comprehensive country-wide studies to improve our understanding of the etiology of anti-GBM disease.

Anti-glomerular basement membrane crescentic glomerulonephritis: A report from India and review of literature

Anti-glomerular basement membrane (anti-GBM) disease is an autoimmune disease that most commonly presents as rapidly progressive glomerulonephritis with or without pulmonary involvement. It is characterized by the presence of antibodies directed to antigenic targets within glomerular and alveolar basement membranes. This study was performed to evaluate the clinicopathological features and outcome in anti-GBM crescentic glomerulonephritis (CrGN) at a tertiary care center in North India over a period of 9 years (January 2004 to December 2012). A diagnosis of anti-GBM CrGN was made in the presence of >50% crescents, linear deposits of IgG along GBM, and raised serum anti-GBM antibody titer. Of 215 cases of CrGN diagnosed during this period, 11 had anti-GBM CrGN. Anti-GBM CrGN was found at all ages but was most common in the third to fifth decade with no gender predilection (mean age 48 +/- 15 years, 13–67 years). Patients presented with a mean serum creatinine of 10.2 +/- 5.3 mg/dl and sub-nephrotic proteinuria. Pulmonary involvement was present in two patients. Myeloperoxidase-antineutrophil cytoplasmic antibody was positive in two (2/11) elderly patients. Follow-up was available in four patients for a range of 30-270 (mean 99.5 ± 114.5) days, two remained dialysis dependent while two died due to uremia and sepsis. Our findings show that anti-GBM disease is a rare cause of CrGN in India, accounting for only 5% of patients. It usually presents as a renal-limited disease and is associated with a poor renal outcome.

Malignant hypertension with an unusual presentation mimicking the immune mediated pulmonary renal syndrome

A 27-year-old man presented at the emergency room with hemoptysis. His blood pressure was 180/100 mm Hg, and he had no history of hypertension. Chest radiographs showed bilateral infiltration, suggestive of alveolar hemorrhage. His laboratory data were consistent with acute kidney injury. His serum creatinine level increased abruptly; therefore, renal biopsy was performed. Steroid pulse therapy was administered because of a strong suspicion of immune-mediated pulmonary renal syndrome. Renal biopsy showed proliferative endarteritis, fibrinoid necrosis, and intraluminal thrombi in the vessels without crescent formation or necrotizing lesions. Steroid pulse therapy rapidly tapered and stopped. His serum creatinine level gradually decreased with strict blood pressure control. Ten months after discharge, his blood pressure was approximately 120/80 mm Hg with a serum creatinine level of 1.98 mg/dL. Pulmonary renal syndrome is generally caused by an immune-mediated mechanism. However, malignant hypertension accompanying renal insufficiency and heart dysfunction causing end-organ damage can create a pulmonary hemorrhage, similar to pulmonary renal syndrome caused by an immune-mediated mechanism. The present case shows that hypertension, a common disease, can possibly cause pulmonary renal syndrome, a rare condition.

Anti-glomerular basement membrane antibody disease: a rare autoimmune disorder affecting the kidney and the lung

Anti-glomerular basement membrane antibody disease is a rare, but well characterized cause of glomerulonephritis. By definition serum anti-GBM antibody and/or a linear binding of IgG detected by direct immunofluorescence (IF) in a histological specimen of the kidney or the lung have to be detected. These antibodies can lead to acute rapid progressive glomerulonephritis(RPGN) and/or pulmonary hemorrhage (PH) because of collagen similarities in the basement membrane. Principally anti-GBM antibody disease can be divided into two groups: anti-GBM antibody disease without PH was regarded as renal-limited anti-GBM antibody disease and that with PH was defined as Goodpasture's syndrome (GPS). The important determinant for the response of therapy and long term diagnosis on anti-GBM disease is early diagnosis to prevent endstage renal disease. Therefore, standard treatment is a combined therapy of plasmapherisis, prednisolone and cyclophosphamide. The aim of this review is an overview of the pathogenesis, clinical presentation, diagnosis and treatment of anti-GBM disease.

Anti-glomerular basement membrane disease: outcomes of different therapeutic regimens in a large single-center Chinese cohort study

Anti-glomerular basement membrane (GBM) disease usually presents with rapidly progressive glomerulonephritis accompanied by pulmonary hemorrhage. The low incidence and fulminant course of disease preclude a large randomized controlled study to define the benefits of any given therapy. We conducted a retrospective survey of 221 consecutive patients seen from 1998 to 2008 in our hospital, and report here the patient and renal survival and the risk factors affecting the outcomes. Considering the similar clinical features of the patients, we could compare the effects of 3 different treatment regimens: 1) combination therapy of plasmapheresis and immunosuppression, 2) steroids and cytotoxic agents, and 3) steroids alone.The patient and renal survival rates were 72.7% and 25.0%, respectively, at 1 year after disease presentation. The serum level of anti-GBM antibodies (increased by 20 U/mL; hazard ratio [HR], 1.16; p = 0.009) and the presentation of positive antineutrophil cytoplasmic antibodies (ANCA) (HR, 2.18; p = 0.028) were independent predictors for patient death. The serum creatinine at presentation (doubling from 1.5 mg/dL; HR, 2.07; p < 0.001) was an independent predictor for renal failure.The combination therapy of plasmapheresis plus corticosteroids and cyclophosphamide had an overall beneficial effect on both patient survival (HR for patient mortality, 0.31; p = 0.001) and renal survival (HR for renal failure, 0.60; p = 0.032), particularly patient survival for those with Goodpasture syndrome (HR for patient mortality, 0.29; p = 0.004) and renal survival for those with anti-GBM nephritis with initial serum creatinine over 6.8 mg/dL (HR for renal failure, 0.52; p = 0.014). The treatment with corticosteroids plus cyclophosphamide was found not to improve the renal outcome of disease (p = 0.73). In conclusion, the combination therapy was preferred for patients with anti-GBM disease, especially those with pulmonary hemorrhage or severe renal damage. Early diagnosis was crucial to improving outcomes.

Clinical features and outcomes of anti-glomerular basement membrane disease in older patients

BACKGROUND

Anti-glomerular basement membrane (GBM) disease is being recognized increasingly in older patients. Disease presentation and outcomes of these patients are unclear.

STUDY DESIGN

Case series.

SETTING & PARTICIPANTS

221 consecutive Chinese patients with anti-GBM disease diagnosed in 1998-2008 in our tertiary referral center. Anti-GBM disease was defined as positive anti-GBM antibodies in circulation and/or linear immunoglobulin G deposition along the GBM on kidney biopsy.

PREDICTOR

Older age, defined as 65 years or older, and antineutrophil cytoplasmic antibody, detected using immunofluorescence and enzyme-linked immunosorbent assay, at presentation.

OUTCOMES

Clinical features, kidney pathologic characteristics, end-stage renal disease (ESRD), and mortality. Multivariate Cox proportional hazard models were used to assess the contribution of age, sex, clinical measures, and treatments to ESRD and mortality.

RESULTS

50 of 221 (22.6%) patients were 65 years or older. Older patients had a male predominance (male/female ratio, 1.9:1). They had a higher proportion of positive antineutrophil cytoplasmic antibody results (46.0% vs 14.6%; P < 0.001), lower prevalence of hemoptysis (26.0% vs 46.2%; P = 0.01), lower urine protein excretion (1.4 ± 1.0 vs 3.9 ± 3.3 g/d; P = 0.001), and higher estimated glomerular filtration rate (eGFR) at presentation (8.4 vs 5.1 mL/min/1.73 m(2); P = 0.007) compared with younger patients. During follow-up, 30 of 37 (81.1%) and 21 of 37 (56.8%) patients developed ESRD and died in the older group compared with 115 of 139 (82.7%) and 35 of 139 (25.2%) in the younger group (P = 0.1 and P = 0.001, respectively). For older patients, multivariate Cox regression analysis showed that higher initial eGFR was an independent predictor for both ESRD (HR, 0.86; 95% CI, 0.78-0.96; P = 0.005) and death (HR, 0.79; 95% CI, 0.66-0.94; P = 0.008).

LIMITATIONS

Not all patients underwent kidney biopsy, especially those with very old age or ESRD at presentation.

CONCLUSIONS

Older patients with anti-GBM disease had milder kidney damage and less pulmonary involvement. Outcomes were predicted by initial eGFR. Thus, early diagnosis was crucial to improve outcomes.