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

[Cocaine-induced vasculitis and mimics of vasculitis]

Cocaine is a psychotropic tropane alkaloid and stimulant drug. Nasal insufflation of cocaine powder is a common route of administration. In Germany, cocaine is frequently adulterated with levamisole, an anthelminthic drug with immunomodulatory effects. Both substances are linked to various autoimmune conditions. Cocaine-induced midline destructive lesions cause a progressive destruction of osteocartilaginous structures within the upper respiratory tract and can mimic localized granulomatosis with polyangiitis. In addition, systemic vasculitis due to cocaine and levamisole has been reported. Differentiation of these conditions from primary vasculitis can be challenging because antineutrophil cytoplasmic antibodies (ANCA) are commonly detected. Early diagnosis of these conditions is crucial as clinical improvement is closely related to drug cessation.

Atypical Anti-Glomerular Basement Membrane Disease

Atypical anti-glomerular basement membrane (anti-GBM) disease is characterized by linear immunoglobulin G (IgG) deposition along the GBM without circulating IgG anti-GBM antibodies. Compared to classic anti-GBM disease, atypical anti-GBM disease tends to be milder with a more indolent course in certain cases. Moreover, pathologic disease pattern is much more heterogenous in atypical anti-GBM disease than in the classic type, which is uniformly characterized by diffuse crescentic and necrotizing glomerulonephritis. Although there is no single well-established target antigen in atypical anti-GBM disease, the target antigen (within the GBM) and the autoantibody type are hypothesized to be different from the classic type. Some patients have the same antigen as the Goodpasture antigen that are detected only by a highly sensitive technique (biosensor analysis). Some cases of atypical anti-GBM disease have autoantibodies of a different subclass restriction like IgG4, or of monoclonal nature. Antibodies targeting antigen/epitope structure other than the Goodpasture antigen can be detected using modified assays in some cases. Patients with IgA- and IgM-mediated anti-GBM disease are known to have negative circulating antibodies because conventional assays do not detect these classes of antibodies. A significant proportion of cases with atypical anti-GBM disease do not have any identifiable antibodies despite extensive evaluation. Nevertheless, extensive evaluation of atypical autoantibodies using modified assays and sensitive techniques should be attempted, if feasible. This review summarizes the recent literature on atypical anti-GBM disease.

Pulmonary renal syndrome: a clinical review

The term "pulmonary renal syndrome" describes a clinical syndrome which is characterised by the presence of both diffuse alveolar haemorrhage and glomerulonephritis. It encompasses a group of diseases with distinctive clinical and radiological manifestations, as well as different pathophysiological processes. The most common diseases implicated are anti-neutrophil cytoplasm antibodies (ANCA)-positive small vessel vasculitis and anti-glomerular basement membrane (anti-GBM) disease. Prompt recognition is required as respiratory failure and end-stage renal failure can rapidly occur. Treatment includes a combination of glucocorticoids, immunosuppression, plasmapheresis and supportive measures. The use of targeted treatments has significantly reduced mortality. Thus, an understanding of pulmonary renal syndrome is essential for the respiratory physician.

Association between kinetic of Anti-Neutrophil Cytoplasmic Antibody (ANCA), renal survival and relapse risk in ANCA-glomerulonephritis

BACKGROUND

Anti-neutrophil cytoplasmic antibody (ANCA) kinetic in ANCA-associated vasculitis with glomerulonephritis (AAV-GN) has been suggested to be associated with AAV relapse. Few studies focused on its association with renal prognosis. Thus, we aimed to investigate the relationship between i) ANCA specificity and evolutive profile, and ii) renal outcomes.

METHODS

This multicentric retrospective study included patients diagnosed with ANCA-GN since 01/01/2000. Patients without ANCA at diagnosis and with fewer than 3 ANCA determinations during follow-up were excluded. We analyzed eGFR variation, renal-free and relapse-free survival according to three ANCA profiles (negative, recurrent, persistent) and to ANCA specificity (MPO or PR3).

RESULTS

Over a follow-up of 56 [34-101] months, a median of 19 [13-25] ANCA determinations were performed for the 134 included patients. Patients with a recurrent/persistent ANCA profile had a lower relapse-free (p = 0.019) survival and tended to have a lower renal survival (p = 0.053) compared to those with negative ANCA profile. Patients with a recurrent/persistent MPO-ANCA profile had the shortest renal survival (p = 0.015) and those with recurrent/persistent PR3-ANCA profile had the worst relapse-free survival (p = 0.013) compared to other profiles. The negative ANCA profile was associated with a greater eGFR recovery. In multivariate regression analysis, it was an independent predictor of a two-fold increase of eGFR at 2-year (OR = 6.79, 95% CI [1.78, 31.4], p = 0.008).

CONCLUSION

ANCA kinetic after ANCA-GN diagnosis is associated with outcomes. MPO-ANCA recurrence/persistence identifies patients with a lower potential of renal recovery and a higher risk of kidney failure, while PR3-ANCA recurrence/persistence identifies patients with a greater relapse risk. Thus, ANCA kinetic may help identify patients with a smoldering disease.

Anti-glomerular Basement Membrane Glomerulonephritis: A Study in Real Life

Introduction

Anti-glomerular basement membrane (anti-GBM) disease is a severe entity with few therapeutic options including plasma exchange and immunosuppressive agents. The aim of this study was to analyze the clinical and pathological features that predict the evolution of end-stage kidney disease (ESKD) and the kidney survival in a cohort of patients with anti-GBM disease with renal involvement in real life.

Methods

A retrospective multicentre observational study including 72 patients from 18 nephrology departments with biopsy-proven anti-GBM disease from 1999 to 2019 was performed. Progression to ESKD in relation to clinical and histological variables was evaluated.

Results

Creatinine at admission was 8.6 (± 4) mg/dL and 61 patients (84.7%) required dialysis. Sixty-five patients (90.3%) underwent plasma exchange. Twenty-two patients (30.6%) presented pulmonary hemorrhage. Kidney survival was worse in patients with creatinine levels > 4.7 mg/dL (3 vs. 44% p < 0.01) and in patients with > 50% crescents (6 vs. 49%; p = 0.03). Dialysis dependence at admission and creatinine levels > 4.7 mg/dL remained independent significant predictors of ESKD in the multivariable analysis [HR (hazard ratio) 3.13 (1.25–7.84); HR 3 (1.01–9.14); p < 0.01]. The discrimination value for a creatinine level > 4.7 mg/dL and 50.5% crescents had an area under the curve (AUC) of 0.9 (95% CI 0.82–0.97; p < 0.001) and 0.77 (95% CI 0.56–0.98; p = 0.008), respectively. Kidney survival at 1 and 2 years was 13.5 and 11%, respectively. Patient survival at 5 years was 81%.

Conclusion

In real life, patients with severe anti-GBM disease (creatinine > 4.7 mg/dL and > 50% crescents) remained with devastating renal prognosis despite plasma exchange and immunosuppressive treatment. New therapies for the treatment of this rare renal disease are urgently needed.

Acute glomerulonephritis

Glomerulonephritis is a heterogeneous group of disorders that present with a combination of haematuria, proteinuria, hypertension, and reduction in kidney function to a variable degree. Acute presentation with full blown nephritic syndrome or rapidly progressive glomerulonephritis is uncommon and is mainly restricted to patients with post-infectious glomerulonephritis, anti-neutrophil cytoplasmic antibodies-associated vasculitis, and anti-glomerular basement membrane disease. Most frequently, patients present with asymptomatic haematuria and proteinuria with or without reduced kidney function. All glomerulonephritis disorders can show periods of exacerbation, but disease flairs characteristically occur in patients with IgA nephropathy or C3 glomerulopathy. The gold standard for the diagnosis of a glomerulonephritis is a kidney biopsy, with a hallmark glomerular inflammation that translates into various histopathological patterns depending on the location and severity of the glomerular injury. Traditionally, glomerulonephritis was classified on the basis of the different histopathological patterns of injury. In the last few years, substantial progress has been made in unravelling the underlying causes and pathogenetic mechanisms of glomerulonephritis and a causal approach to the classification of glomerulonephritis is now favoured over a pattern-based approach. As such, glomerulonephritis can be broadly classified as immune-complex glomerulonephritis (including infection-related glomerulonephritis, IgA nephropathy, lupus nephritis, and cryoglobulinaemic glomerulonephritis), anti-neutrophil cytoplasmic antibodies-associated (pauci-immune) glomerulonephritis, anti-glomerular basement membrane glomerulonephritis, C3 glomerulopathy, and monoclonal immunoglobulin-associated glomerulonephritis. We provide an overview of the clinical presentation, pathology, and the current therapeutic approach of the main representative disorders in the spectrum of glomerulonephritis.

Case report: A study on the de novo KMT2D variant of Kabuki syndrome with Goodpasture's syndrome by whole exome sequencing

Kabuki syndrome (KS) is a rare genetic disorder characterized by dysmorphic facial features, skeletal abnormalities, and intellectual disability. KMT2D and KDM6A were identified as the main causative genes. To our knowledge, there exist no cases of KS, which were reported with pneumorrhagia. In this study, a 10-month-old male was diagnosed to have KS with typical facial features, skeletal anomalies, and serious postnatal growth retardation. Whole exome sequencing of the trio family revealed the presence of a de novo KMT2D missense variant (c.15143G > A, p. R5048H). The child was presented to the pediatric emergency department several times because of cough, hypoxemia, and anemia. After performing chest CT and fiberoptic bronchoscopy, we found that the child had a pulmonary hemorrhage. During research on the cause of pulmonary hemorrhage, the patient's anti-GBM antibodies gradually became positive, and the urine microalbumin level was elevated at the age of 12-month-old. After glucocorticoids and immunosuppressant therapy, the patient became much better. But he had recurrent pulmonary hemorrhage at the age of 16 months. Therefore, the patient underwent digital subtraction angiography (DSA). However, the DSA showed three abnormal bronchial arteries. This single case expands the phenotypes of patients with KS and Goodpasture's syndrome, which were found to have a de novo KMT2D missense variant.

Anti-glomerular basement membrane disease (Goodpasture disease): From pathogenesis to plasma exchange to IdeS

Anti-glomerular basement membrane (GBM) disease (Goodpasture disease) often presents with severe kidney failure and pulmonary hemorrhage. Anti-GBM antibodies are pathogenic, and other autoantibodies such as laminin-521 have been identified recently, potentially indicating a subset with a more severe disease phenotype and poor prognosis. Around 30%-40% of patients are also anti-neutrophil cytoplasmatic antibody (ANCA)-positive and this subset combines features of anti-GBM disease and ANCA-associated vasculitis, with particular impact on long-term treatment. A combination of therapeutic plasma exchange (or immunoadsorption), cyclophosphamide, and glucocorticoids is considered standard of care management, but despite early initiation, patients with poor prognostic factors often remain dialysis dependent. Imlifidase (IdeS), capable to cleave IgG within hours, has been tested in a phase II trial. Among 15 patients, 10 with poor prognosis at baseline (eGFR <15 ml/min/1.73 m² ) were dialysis independent at 6 months. Further developments are needed to refine treatment approaches in anti-GBM disease.

Autoimmune glomerulonephritis in a multiple sclerosis patient after cladribine treatment

BACKGROUND

Oral cladribine is an approved disease-modifying drug for the treatment of relapsing multiple sclerosis. In controlled clinical trials as well as in post marketing safety assessments, autoimmune conditions have not yet been reported as a specific side effect of cladribine.

OBJECTIVE AND RESULTS

Here, we report a case of anti-glomerular basement membrane antibody-mediated glomerulonephritis that occurred shortly after the fourth cladribine treatment cycle.

CONCLUSION

Neurologists should be attentive to the development of secondary autoimmunity in cladribine-treated patients.

Anti-glomerular basement membrane disease mediated by IgG and IgA: a case report

Background

Anti-glomerular basement membrane (anti-GBM) disease is a rare autoimmune condition responsible for rapidly progressive glomerulonephritis. This disease is usually mediated by IgG autoantibodies against the noncollagenous domain of the α3(IV) collagen chain. In rare cases, IgA or IgM anti-GBM antibodies are involved. This raises the question of whether there are different types of antibody-mediated anti-GBM disease at the same time.

Case report

A 37-year-old woman with anti-GBM disease mediated by IgG and IgA. The patient developed rapidly progressive glomerulonephritis with nephrotic syndrome. Indirect immunofluorescence analysis indicated the presence of IgG and IgA antibodies reactive with a basement membrane component, identified by enzyme-linked immunoadsorbent assay and Western blotting as the α3(IV) collagen chain. After plasmapheresis and immunotherapy (steroids and cyclophosphamide), much improved the massive proteinuria and renal function. Follow up to date, she had normal renal function without proteinuria.

Conclusions

This is the first case report of anti-GBM disease mediated by IgG and IgA. If the clinical presentation and histopathological findings are suggestive of atypical anti-GBM disease, alternative laboratory tests such as Western blotting analysis can be used to confirm the diagnosis.

A Review of Clinical and Imaging Features of Diffuse Pulmonary Hemorrhage

OBJECTIVE. The purpose of this article is to review the clinical and imaging features of diffuse pulmonary hemorrhage. CONCLUSION. Diffuse pulmonary hemorrhage is a life-threatening syndrome associated with a wide variety of underlying pathologic categories. Nonspecific clinical and imaging features pose challenges to promptly diagnosing this condition. Chest radiography commonly shows alveolar opacification, and CT reveals the extent of disease. Integration of clinical, radiologic, laboratory, and pathologic findings facilitates timely diagnosis and etiologic identification.

Focus on the Gut-Kidney Axis in Health and Disease

The recent new developments in technology with culture-independent techniques including genome sequencing methodologies shed light on the identification of microbiota bacterial species and their role in health and disease. Microbiome is actually reported as an important predictive tool for evaluating characteristic shifts in case of disease. Our present review states the development of different renal diseases and pathologies linked to the intestinal dysbiosis, which impacts on host homeostasis. The gastrointestinal–kidney dialogue provides intriguing features in the pathogenesis of several renal diseases. Without any doubt, investigation of this interconnection consists one of the most cutting-edge areas of research with potential implications on our health.

The impact of race on hospitalization outcomes for goodpasture's syndrome in the United States: nationwide inpatient sample 2003-2014

BACKGROUND

Goodpasture's syndrome is a rare and life-threatening autoimmune disease. While Goodpasture's syndrome is well described in Caucasian and Asian populations, its prevalence and outcomes among African American and Hispanic populations are unclear. We conducted this study to assess the impacts of race on hospital outcomes among patients with Goodpasture's syndrome.

METHODS

The National Inpatient Sample database was used to identify hospitalized patients with a principal diagnosis of Goodpasture's syndrome from 2003 to 2014. Goodpasture's syndrome patients were grouped based on their race. The differences in-hospital supportive care for organ failure and outcomes between Caucasian, African American, and Hispanic Goodpasture's syndrome patients were assessed using logistic regression analysis.

RESULTS

Nine hundred and sixty-four patients were hospitalized with a primary diagnosis of Goodpasture's syndrome. Of these, 786 were included in the analysis: 622 (79%) were Caucasian, 73 (9%) were African American, and 91 (12%) were Hispanic. Hispanics had significantly lower use of plasmapheresis. The use for mechanical ventilation, noninvasive ventilation support, and renal replacement therapy in African Americans and Hispanics were comparable to Caucasians. There was no significant difference in organ failure, sepsis, and in-hospital mortality between African Americans and Caucasians. In contrast, Hispanics had higher in-hospital mortality than Caucasians but similar risk of organ failure and sepsis.

CONCLUSION

African American and Hispanic populations account for 9% and 12% of hospitalizations for Goodpasture's syndrome, respectively. While there is no significant difference in in-hospital mortality between African Americans and Caucasians, Hispanics with Goodpasture's syndrome carry a higher in-hospital mortality compared to Caucasians.

Heavy chain deposition disease presenting with raised anti-GBM antibody levels; a case report

Background

Monoclonal immunoglobulin deposition disease (MIDD) is a rare condition accounting for < 1% of histopathological diagnoses made on kidney biopsy¹. The best outcomes are seen in those diagnosed and treated promptly, but delay to diagnosis is common with the largest series reporting a median time from onset of renal impairment to diagnosis of 12 months². Here, we report a case of the heavy chain subset of MIDD presenting with positive anti-glomerular basement membrane (anti-GBM) antibodies obscuring the true diagnosis.

Case presentation

Here, we present a challenging case presenting with oedema, haematoproteiuria, and new renal impairment. Anti-GBM antibodies were positive and prompted treatment as atypical anti-GBM disease. However, they were ultimately proven to be monoclonal and secondary to myeloma. The final diagnosis facilitated effective myeloma treatment which led to complete remission and independence from renal replacement therapy.

Conclusions

This case reinforces the importance of comprehensive histopathological and haematological assessment in making the correct diagnosis. Here it facilitated effective treatment and recovery of renal function.

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

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

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.

Inpatient Burden and Mortality of Goodpasture's Syndrome in the United States: Nationwide Inpatient Sample 2003-2014

Background: Goodpasture’s syndrome is a rare, life-threatening, small vessel vasculitis. Given its rarity, data on its inpatient burden and resource utilization are lacking. We conducted this study aiming to assess inpatient prevalence, mortality, and resource utilization of Goodpasture’s syndrome in the United States. Methods: The 2003–2014 National Inpatient Sample was used to identify patients with a principal diagnosis of Goodpasture’s syndrome. The inpatient prevalence, clinical characteristics, in-hospital treatment, end-organ failure, mortality, length of hospital stay, and hospitalization cost were studied. Multivariable logistic regression was performed to identify independent factors associated with in-hospital mortality. Results: A total of 964 patients were admitted in hospital with Goodpasture’s syndrome as the principal diagnosis, accounting for an overall inpatient prevalence of Goodpasture’s syndrome among hospitalized patients in the United States of 10.3 cases per 1,000,000 admissions. The mean age of patients was 54 ± 21 years, and 47% were female; 52% required renal replacement therapy, whereas 39% received plasmapheresis during hospitalization. Furthermore, 78% had end-organ failure, with renal failure and respiratory failure being the two most common end-organ failures. The in-hospital mortality rate was 7.7 per 100 admissions. The factors associated with increased in-hospital mortality were age older than 70 years, sepsis, the development of respiratory failure, circulatory failure, renal failure, and liver failure, whereas the factors associated with decreased in-hospital mortality were more recent year of hospitalization and the use of therapeutic plasmapheresis. The median length of hospital stay was 10 days. The median hospitalization cost was $75,831. Conclusion: The inpatient prevalence of Goodpasture’s syndrome in the United States is 10.3 cases per 1,000,000 admissions. Hospitalization of patients with Goodpasture’s syndrome was associated with high hospital inpatient utilization and costs.

Hémorragies intra-alvéolaires

L’hémorragie intra-alvéolaire (HIA), maladie rare, est une urgence thérapeutique, car elle peut conduire rapidement vers une insuffisance respiratoire aiguë asphyxiante avec décès. La triade, hémoptysie–anémie–infiltrat radiologique, suggère le diagnostic d’HIA, mais elle peut manquer dans deux tiers des cas, y compris chez des patients en détresse respiratoire. La tomodensitométrie thoracique peut aider dans les formes atypiques. Le diagnostic d’HIA repose sur la réalisation d’un lavage bronchoalvéolaire. Les étiologies en sont très nombreuses. Il importera de séparer, en urgence, les HIA d’origine non immune, avec un dépistage de celles d’origine septique qui doivent bénéficier d’une enquête microbiologique ciblée et cardiovasculaire avec la réalisation d’une échographie cardiaque, des HIA immunes (les vascularites liées aux anticorps anticytoplasme des polynucléaires neutrophiles, les connectivites et le syndrome de Goodpasture), avec la recherche d’autoanticorps et la réalisation de biopsies au niveau des organes facilement accessibles. La biopsie pulmonaire doit rester exceptionnelle. En cas d’HIA immune inaugurale, un traitement par stéroïdes et cyclophosphamide peut être débuté. Les indications du rituximab commencent à être mieux établies. Le bénéfice des échanges plasmatiques est débattu. En cas de réapparition d’infiltrats pulmonaires, chez un patient suivi pour une HIA immune, on s’efforcera d’écarter une infection dans un premier temps.

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.