Fever and prodromal infections in anti-glomerular basement membrane disease

An Unusual Case of Anti-Glomerular Basement Membrane Disease and Phospholipase A2 Receptor-Associated Membranous Nephropathy After Exposure to Hydrocarbons

We present a rare case of a patient with toluene exposure manifesting as anti-glomerular basement membrane (GBM) disease on a background of phospholipase A2 receptor (PLA2R)-associated membranous nephropathy. A 23-year-old man presented to the emergency department with hypertension, headache, hemoptysis, anemia, acute kidney injury, glomerular hematuria, and proteinuria. He endorsed repeated exposure to toluene-containing products while repairing dirt bikes. Serologies were positive for anti-GBM antibodies. Kidney biopsy showed crescentic glomerulonephritis with linear immunoglobulin G and granular PLA2R staining by immunofluorescence. He was initially treated with high-dose steroids, plasmapheresis, and hemodialysis for pulmonary-renal syndrome followed by oral cyclophosphamide and prednisone, which were discontinued after 3 months when follow-up biopsies confirmed little chance for renal recovery. He remained on dialysis 1 year later. This case exhibits a unique presentation of anti-GBM syndrome and underlying membranous nephropathy following repeated hydrocarbon exposure. Inhaled toxins promote recurrent localized inflammation, unmasking previously hidden epitopes. Early diagnosis and appropriate use of immunosuppressive and extracorporeal therapies are necessary to prevent morbidity and to improve survival in this rare condition.

The Prevalence and Characteristics of Circulating IgA Anti-Glomerular Basement Membrane Autoantibodies in Anti-Glomerular Basement Membrane Disease

Introduction

In some cases, immunoglobulin (IgA)-mediated antiglomerular basement membrane (anti-GBM) disease has been reported. Whether circulating IgA anti-GBM antibodies affect the clinico-pathologic characteristics and outcome of typical anti-GBM disease deserves further study.

Methods

Circulating IgA anti-α3(IV)NC1 antibodies were examined by enzyme-linked immunosorbent assay (ELISA) using recombinant human α3(IV)NC1 as solid phase antigens in 107 patients with anti-GBM disease and 115 controls. Clinical, pathological, and follow-up data of patients were retrospectively analyzed.

Results

Circulating IgA anti-α3(IV)NC1 antibodies were found in 18.7% (20/107) of patients with anti-GBM disease but were not detected in healthy controls or in patients with other glomerular diseases. The positivity of circulating IgA anti-α3(IV)NC1 antibodies was not associated with whether the patient was with combined IgA nephropathy or other glomerulonephritis. Kidney immunofluorescence showed no statistical difference in IgA deposition between patients with circulating IgA anti-α3(IV)NC1 antibodies and patients without (30.0% vs. 40.4%, P = 0.725). The titers of circulating immunoglobulin G (IgG) anti-α3(IV)NC1 antibodies in patients with circulating IgA anti-α3(IV)NC1 antibodies were significantly higher than those without (200 [183.3, 200] vs. 161 [85.5, 200] U/ml, P = 0.005). There were no significant differences in kidney outcome and mortality between the 2 groups.

Conclusion

Circulating IgA anti-α3(IV)NC1 antibodies occurred in 18.7% (20/107) of patients with anti-GBM in our center and were specific to anti-GBM disease. Patients with circulating IgA anti-α3(IV)NC1 antibodies showed a higher levels of serum IgG anti-α3(IV)NC1 antibodies than those without.

Autoimmunity in Anti-Glomerular Basement Membrane Disease: A Review of Mechanisms and Prospects for Immunotherapy

Anti-glomerular basement membrane (anti-GBM) disease is an organ-specific autoimmune disorder characterized by autoantibodies against the glomerular and alveolar basement membranes, leading to rapidly progressive glomerulonephritis and severe alveolar hemorrhage. The noncollagenous domain of the α3 chain of type IV collagen, α3(IV)NC1, contains the main target autoantigen in this disease. Epitope mapping studies of α3(IV)NC1 have identified several nephritogenic epitopes and critical residues that bind to autoantibodies and trigger anti-GBM disease. The discovery of novel target antigens has revealed the heterogeneous nature of this disease. In addition, both epitope spreading and mimicry have been implicated in the pathogenesis of anti-GBM disease. Epitope spreading refers to the development of autoimmunity to new autoepitopes, thus worsening disease progression, whereas epitope mimicry, which occurs via sharing of critical residues with microbial peptides, can initiate autoimmunity. An understanding of these autoimmune responses may open opportunities to explore potential new therapeutic approaches for this disease. We review how current advances in epitope mapping, identification of novel autoantigens, and the phenomena of epitope spreading and mimicry have heightened the understanding of autoimmunity in the pathogenesis of anti-GBM disease, and we discuss prospects for immunotherapy.

Mycobacterium avium Complex Lung Disease Complicated With Antiglomerular Basement Membrane Disease: A Case Report

While both Mycobacterium avium complex (MAC) lung diseases and antiglomerular basement membrane (anti-GBM) antibody disease may cause hemoptysis, no case presenting hemoptysis having both diseases has been reported. A woman in her 80s was admitted due to hemoptysis with acute respiratory failure. MAC was isolated from her sputum, and a positive report for anti-GBM antibody was confirmed in screening for hematuria. This patient has been successfully treated with systemic corticosteroid therapy followed by combination chemotherapy against MAC. Although anti-GBM disease is a rare condition, screening might be recommended in case of uncontrollable hemoptysis as MAC lung disease with hematuria.

A Case of Paediatric Anti-Glomerular Basement Membrane Disease Associated with Thrombotic Thrombocytopenic Purpura

Anti-GBM disease is a rare vasculitis that causes rapid progressive glomerulonephritis and pulmonary haemorrhage. It is usually an adult diagnosis with isolated paediatric cases reported. Thrombotic thrombocytopenic purpura (TTP) is a rare thrombotic microangiopathy mainly affecting adults that causes multiorgan ischaemia, microangiopathic haemolytic anaemia, and thrombocytopenia. We present the first paediatric case of concurrent anti-GBM disease and TTP. A 14-year-old boy presented with acute kidney failure and severe pulmonary haemorrhage due to anti-GBM disease, confirmed on auto-antibody testing. There was thrombocytopenia and moderately low ADAMTS13 activity suggestive of TTP. The renal prognosis was poor with a need for dialysis. He was severely unwell with pulmonary haemorrhages requiring the use of extracorporeal membrane oxygenation (ECMO). His disease was treated with corticosteroids, plasma exchange (PEX), rituximab, and cyclophosphamide, resulting in remission. Anti-GBM disease is rare in children but should be considered in those presenting with acute kidney injury, particularly where there has been exposure to pulmonary irritants. An aggressive presentation warrants aggressive treatment with methylprednisolone, PEX, and cyclophosphamide. Rituximab may benefit patients that have concurrent TTP. TTP may exacerbate pulmonary disease, but complete respiratory recovery is possible. Disease relapse is rare in the paediatric age group, and these patients are candidates for kidney transplantation.

An Emerging Role of TIM3 Expression on T Cells in Chronic Kidney Inflammation

T cell immunoglobulin domain and mucin domain 3 (TIM3) was initially identified as an inhibitory molecule on IFNγ-producing T cells. Further research discovered the broad expression of TIM3 on different immune cells binding to multiple ligands. Apart from its suppressive effects on the Th1 cells, recent compelling experiments highlighted the indispensable role of TIM3 in the myeloid cell-mediated inflammatory response, supporting that TIM3 exerts pleiotropic effects on both adaptive and innate immune cells in a context-dependent manner. A large number of studies have been conducted on TIM3 biology in the disease settings of infection, cancer, and autoimmunity. However, there is a lack of clinical evidence to closely evaluate the role of T cell-expressing TIM3 in the pathogenesis of chronic kidney disease (CKD). Here, we reported an intriguing case of Mycobacterium tuberculosis (Mtb) infection that was characterized by persistent overexpression of TIM3 on circulating T cells and ongoing kidney tubulointerstitial inflammation for a period of 12 months. In this case, multiple histopathological biopsies revealed a massive accumulation of recruited T cells and macrophages in the enlarged kidney and liver. After standard anti-Mtb treatment, repeated renal biopsy identified a dramatic remission of the infiltrated immune cells in the tubulointerstitial compartment. This is the first clinical report to reveal a time-course expression of TIM3 on the T cells, which is pathologically associated with the progression of severe kidney inflammation in a non-autoimmunity setting. Based on this case, we summarize the recent findings on TIM3 biology and propose a novel model of CKD progression due to the aberrant crosstalk among immune cells.

Streptococcus mutans induces IgA nephropathy-like glomerulonephritis in rats with severe dental caries

The mechanisms underlying immunoglobulin A nephropathy (IgAN), the most common chronic form of primary glomerulonephritis, remain poorly understood. Streptococcus mutans, a Gram-positive facultatively anaerobic oral bacterium, is a common cause of dental caries. In previous studies, S. mutans isolates that express Cnm protein on their cell surface were frequently detected in IgAN patients. In the present study, inoculation of Cnm-positive S. mutans in the oral cavities of 2-week-old specific-pathogen free Sprague-Dawley rats fed a high-sucrose diet for 32 weeks produced severe dental caries in all rats. Immunohistochemical analyses of the kidneys using IgA- and complement C3-specific antibodies revealed positive staining in the mesangial region. Scanning electron microscopy revealed a wide distribution of electron dense deposits in the mesangial region and periodic acid-Schiff staining demonstrated prominent proliferation of mesangial cells and mesangial matrix. These results suggest that IgAN-like glomerulonephritis was induced in rats with severe dental caries by Cnm-positive S. mutans.

Atypical anti-glomerular basement membrane disease complicated by methicillin-susceptible Staphylococcus aureus infection-related rapidly progressive glomerulonephritis: a case report and literature review

Atypical anti-glomerular basement membrane (GBM) disease, which is characterized by low levels of or negativity for anti-GBM antibodies in circulation but positivity in the kidney, has been recognized in this decade. However, a therapeutic strategy has not been established to date because its outcome is better than that of classic anti-GBM disease. This case report and literature review highlight atypical anti-GBM disease in infection-related rapidly progressive glomerulonephritis. A 72-year-old Japanese man diagnosed with methicillin-susceptible Staphylococcus aureus (MSSA)-induced vertebral osteomyelitis experienced for 2 months was referred to our hospital because of renal insufficiency. He developed rapidly progressive glomerulonephritis with a serum creatinine level of 6.8 mg/dL, C-reactive protein level of 9.7 mg/dL, urinary protein-to-creatinine ratio of 3.37 g/gCr, and gross hematuria. The serum anti-GBM antibody concentration was 3.5 U/mL, which was slightly above the normal range (< 3.0 U/mL). Conservative treatment, mainly with antibiotics, improved the symptoms and renal function. The serum anti-GBM antibody concentration peaked at 4.0 U/mL on day 7 and decreased to an undetectable range at the end of eight-week antibiotic therapy. This is the first case report describing the presentation and disappearance of serum anti-GBM antibody in a patient with MSSA infection. Conservative treatment may be effective for patients with atypical anti-GBM disease complicated by infectious diseases.

The clinical and immunological features of the post-extracorporeal shock wave lithotripsy anti-glomerular basement membrane disease

Introduction

Extracorporeal shock wave lithotripsy (ESWL) is a noninvasive modality to treat urolithiasis, with complications including tissue damage and hematoma of kidney parenchyma. Anti-glomerular basement membrane (GBM) disease is suggested to be a rare complication of ESWL since it was reported in several cases to occur after ESWL. However, the clinical and immunological features of the ESWL-associated anti-GBM disease have not been fully investigated so far.

Case Presentation

Here, we present the clinical, pathological, and immunological characteristics of three patients with the post-ESWL anti-GBM disease in our hospital. Anti-GBM disease occurred within a median of 22 months after ESWL treatment. It presented with similar clinical features to the classic anti-GBM disease, including fever, gross hematuria, and rapidly progressive glomerulonephritis (RPGN) with poor renal prognosis. Sera from all patients recognized the α3(IV)NC1 in GBM, but with IgG2 and IgG4 as the dominant IgG subclasses.

Conclusion

Although further exploration is required to prove the causal relationship in this rare condition, our study reminds physicians that patients developing acute renal insufficiency after ESWL should lead to the suspicion of anti-GBM disease and in-time diagnosis and treatment.

Experimental Antiglomerular Basement Membrane GN Induced by a Peptide from Actinomyces

BACKGROUND

Antiglomerular basement membrane (anti-GBM) disease is associated with HLA-DRB1*1501 (the major predisposing genetic factor in the disease), with α3_127-148 as a nephritogenic T and B cell epitope. Although the cause of disease remains unclear, the association of infections with anti-GBM disease has been long suspected.

METHODS

To investigate whether microbes might activate autoreactive T and B lymphocytes via molecular mimicry in anti-GBM disease, we used bioinformatic tools, including BLAST, SYFPEITHI, and ABCpred, for peptide searching and epitope prediction. We used sera from patients with anti-GBM disease to assess peptides recognized by antibodies, and immunized WKY rats and a humanized mouse model (HLA-DR15 transgenic mice) with each of the peptide candidates to assess pathogenicity.

RESULTS

On the basis of the critical motif, the bioinformatic approach identified 36 microbial peptides that mimic human α3_127-148. Circulating antibodies in sera from patients with anti-GBM recognized nine of them. One peptide, B7, derived from Actinomyces species, induced proteinuria, linear IgG deposition on the GBM, and crescent formation when injected into WKY rats. The antibodies to B7 also targeted human and rat α3_127-148. B7 induced T cell activation from human α3_127-148-immunized rats. T cell responses to B7 were detected in rats immunized by Actinomyces lysate proteins or recombinant proteins. We confirmed B7's pathogenicity in HLA-DR15 transgenic mice that developed kidney injury similar to that observed in α3_135-145-immunized mice.

CONCLUSIONS

Sera from patients with anti-GBM disease recognized microbial peptides identified through a bioinformatic approach, and a peptide from Actinomyces induced experimental anti-GBM GN by T and B cell crossreactivity. These studies demonstrate that anti-GBM disease may be initiated by immunization with a microbial peptide.

Severe Infection in Anti-Glomerular Basement Membrane Disease: A Retrospective Multicenter French Study

In patients presenting with anti-glomerular basement membrane (GBM) disease with advanced isolated kidney involvement, the benefit of intensive therapy remains controversial due to adverse events, particularly infection. We aim to describe the burden of severe infections (SI) (requiring hospitalization or intravenous antibiotics) and identify predictive factors of SI in a large cohort of patients with anti-GBM disease. Among the 201 patients (median [IQR] age, 53 [30–71] years) included, 74 had pulmonary involvement and 127 isolated glomerulonephritis. A total of 161 SI occurred in 116 patients during the first year after diagnosis. These infections occurred during the early stage of care (median [IQR] time, 13 [8–19] days after diagnosis) with mainly pulmonary (45%), catheter-associated bacteremia (22%) and urinary tract (21%) infections. In multivariable analysis, positive ANCA (HR [95% CI] 1.62 [1.07−2.44]; p = 0.02) and age at diagnosis (HR [95% CI] 1.10 [1.00–1.21]; p = 0.047) remained independently associated with SI. Age-adjusted severe infection during the first three months was associated with an increased three-year mortality rate (HR [95% CI] 3.13 [1.24–7.88]; p = 0.01). Thus, SI is a common early complication in anti-GBM disease, particularly in the elderly and those with positive anti-neutrophil cytoplasmic antibodies (ANCA). No significant association was observed between immunosuppressive strategy and occurrence of SI.

Anti-glomerular basement membrane nephritis with bronchial carcinoma: a case report

Renal insufficiency is common among patients with various types of malignant tumors. However, the occurrence of anti-glomerular basement membrane (GBM) nephritis in a patient with a malignant tumor is relatively rare. Here, we describe a patient with bronchial carcinoma who exhibited acute kidney injury, hematuria, and non-nephrotic-range proteinuria. The patient had positive serum anti-GBM antibody findings and biopsy-proven anti-GBM nephritis. This is a rare instance of anti-GBM nephritis in a patient with a malignant solid tumor. Neoplasia was presumed to contribute to the development of anti-GBM nephritis through secretion of tumor-related antigens or unusual exposure to GBM.

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.

Discontinuation of Hemodialysis in a Patient with Anti-GBM Disease by the Treatment with Corticosteroids and Plasmapheresis despite Several Predictors for Dialysis-Dependence

A 26-year-old man highly suspected of having antiglomerular basement membrane (GBM) disease was treated with corticosteroid pulse therapy 9 days after initial infection-like symptoms with high procalcitonin value. The patient required hemodialysis the next day of the treatment due to oliguria. In addition to corticosteroid therapy, plasmapheresis was introduced and the patient could discontinue hemodialysis 43 days after the treatment. Kidney biopsy after initiation of hemodialysis confirmed anti-GBM disease with 86.3% crescent formation. Physician should keep in mind that active anti-GBM disease shows even high procalcitonin value in the absence of infection. To pursue recovery of renal function, the challenge of the immediate and persistent treatment with high-dose corticosteroids plus plasmapheresis for highly suspected anti-GBM disease is vitally important despite the presence of reported predictors for dialysis-dependence including oliguria and requiring hemodialysis at presentation.