Antimitochondrial autoantibodies in anti-glomerular basement membrane disease

Anti-glomerular basement membrane (GBM) disease is characterized by the production of an autoantibody with very restricted specificity, with no evidence of polyclonal B cell activation. It was therefore surprising to find that in a solid-phase ELISA a proportion of anti-GBM sera showed significant binding to pyruvate dehydrogenase (PDH), a reactivity usually associated with the antimitochondrial autoantibodies (AMA) found in primary biliary cirrhosis (PBC). The specificity of this reactivity was confirmed by inhibition and competition experiments. The AMA found in anti-GBM sera were of much lower affinity than those found in PBC sera, and recognized a more restricted set of species (mainly the 55-kD and occasionally the 74-kD component of PDH). However, it was possible to block the binding in a Western blot of an anti-GBM serum to both the 55-kD and 74-kD species with F(ab')2 fragments prepared from a PBC serum. Although AMA have been found in diseases other than PBC, such diseases have usually been characterized by polyclonal B cell activation. The stimulus to the production of AMA in anti-GBM disease, and their significance in pathogenesis (if any), are unknown.     

Susceptibility to anti-glomerular basement membrane disease and Goodpasture syndrome is linked to MHC class II genes and the emergence of T cell-mediated immunity in mice

We developed a new mouse model of human anti-glomerular basement membrane (GBM) disease to better characterize the genetic determinants of cell-mediated injury. While all major histocompatibility complex (MHC) haplotypes (H-2a, k, s, b, and d) immunized with alpha3 NC1 domains of type IV collagen produce anti-alpha3(IV) NC1 antibodies that cross-react with human Goodpasture [anti-GBM/anti-alpha3(IV) NC1] autoantibodies, only a few strains developed nephritis and lung hemorrhage associated with Goodpasture syndrome. Crescentic glomerulonephritis and lung hemorrhage were MHC-restricted in haplotypes H-2s, b, and d (A beta/A alpha region in H-2s) and associated with the emergence of an IL-12/Th1-like T cell phenotype. Lymphocytes or anti-alpha3(IV) NC1 antibodies from nephritogenic strains transfer disease to syngeneic recipients. However, passive transfer of isogenic alpha3(IV) NC1 antibodies into -/- T cell receptor-deficient mice failed to produce nephritis. Finally, nephritis and its associated IL-12/Th1-like T cell response attenuate in disease-susceptible mice tolerized orally to alpha3(IV) collagen before immunization. Our findings suggest collectively, as a hypothesis, that anti-GBM antibodies in mice only facilitate disease in MHC haplotypes capable of generating nephritogenic lymphocytes with special T cell repertoires.     

Characteristics and outcome of anti-glomerular basement membrane disease: a single-center experience

The relative virulence and avirulence of Mycobacterium tuberculosis strains H37Rv and H37Ra were previously defined using animal infection models. To investigate host species' specificity of mycobacterial virulence, growth of the 2 M. tuberculosis strains in human monocyte-derived macrophages in vitro was studied. Mycobacterial growth was evaluated by acid-fast staining, electron microscopy, and colony-forming units (cfu) assay. As expected, the 2 strains demonstrated significantly different growth rates in mouse macrophages in vitro (53 h for H37Rv, 370 h for H37Ra). In marked contrast, in human macrophages the average division times of the strains were nearly equal (80 h for H37Rv and 76 h for H37Ra by cfu measurement, and 96 h for H37Rv and 104 h for H37Ra by acid-fast staining). These findings indicate that observations of mycobacterial virulence in murine systems may not necessarily translate to the human system, in which different mechanisms to control mycobacterial growth may be expressed.     

Targets of alloantibodies in Alport anti-glomerular basement membrane disease after renal transplantation

A minority of patients with Alport syndrome develop anti-GBM disease in their allografts after renal transplantation. Clinically, the renal disease appears indistinguishable from Goodpasture's disease of native kidneys, in which the target of autoantibodies had been identified as the NC1 domain of the alpha 3 chain of type IV collagen, alpha 3(IV)NC1. However, in the majority of cases, Alport syndrome is due to mutations in the gene encoding the alpha 5 chain of type IV collagen, located on the X chromosome. Neither chain is detectable in the glomerular basement membrane (GBM) of most patients with Alport syndrome. We investigated the targets of the alloantibodies of 12 Alport patients who developed post-transplant anti-GBM disease by Western blotting onto recombinant NC1 domains made in insect cells. Binding to these antigens, for both typical Goodpasture and Alport anti-GBM antibodies, was strong and conformation-sensitive. Nine antibodies showed selective binding to alpha 5(IV)NC1. This specificity was confirmed by the demonstration of binding to a 26 kDa band of collagenase-solubilized human GBM, and/or binding to normal epidermal as well as renal basement membranes by indirect immunofluorescence. One antibody showed binding to alpha 5 and alpha 3(IV)NC1, while two showed predominant binding to alpha 3(IV)NC1. All seven patients whose pedigree or mutation analysis showed X-linked inheritance had predominant anti-alpha 5 reactivity. One with predominant anti-alpha 3 reactivity had a COL4A3 mutation. These findings show that human anti-GBM disease can be associated with antibodies directed towards different molecular targets. Alpha 5(IV)NC1 is the primary target in most patients with X-linked Alport syndrome who develop post-transplant anti-GBM disease.     

Leucocyte membrane expression of proteinase 3 correlates with disease activity in patients with Wegener's granulomatosis

Wegener's granulomatosis (WG) is an inflammatory disorder characterized by granulomatous inflammation and vasculitis, and is strongly associated with antineutrophil cytoplasmic antibodies (ANCA). ANCA in patients with WG are directed against proteinase 3 (Pr3) in most of the cases. In vitro, upon neutrophil priming, ANCA antigens are expressed on the cell surface, thereby becoming available for interaction with ANCA. Subsequently, these neutrophils become activated. Since ANCA can only interact with leucocytes when the ANCA antigens are present on the cell surface, we questioned whether Pr3 is already expressed on the membranes of circulating granulocytes and monocytes of patients with WG, and whether Pr3 expression is related to disease activity, so explaining the systemic nature and severity of the disease. The expression of Pr3, and other ANCA antigens, i.e. myeloperoxidase (MPO) and human leucocyte elastase (HLE), was analysed on circulating granulocytes and monocytes by flow cytometry, using a non-activating whole-blood method. Disease activity was quantitated using the Birmingham Vasculitis Activity Score (BVAS). Seventeen patients with active WG and anti-Pr3 antibodies were included in this study. Nine of these patients were also analysed at the time of remission. Twelve patients with sepsis served as positive controls, and 10 healthy volunteers as negative controls for granulocyte/monocyte activation. Pr3 expression on neutrophils was increased in patients with active WG compared to patients with quiescent disease and healthy controls. On monocytes, no differences in Pr3 expression were found between those groups. Furthermore, the expression of MPO and HLE did not differ between patient groups and healthy controls. Upon follow-up, the expression of Pr3 on neutrophils from patients with active WG decreased when patients went into remission. Pr3 expression on neutrophils correlated with the BVAS score (r = 0.40, P < 0.05). In conclusion, circulating neutrophils from patients with active WG have increased expression of Pr3. In addition, the expression of Pr3 correlates with disease activity, suggesting that the availability of Pr3 for interaction with ANCA plays a central role in the disease process.     

Disseminated histoplasmosis and Wegener's granulomatosis

Disseminated histoplasmosis is an unusual complication in endemic areas and has been reported in patients with an immunodeficient state, either from human immunodeficiency virus (HIV) infection or transplantation. In the non-HIV population, rare cases of disseminated histoplasmosis have been reported in patients with leukemia and Hodgkin's disease and patients receiving steroid therapy for various diseases. We report a case of disseminated histoplasmosis in a patient with Wegener's granulomatosis.     

A rapid ELISA for measurement of anti-glomerular basement membrane antibodies using microwaves

The presence of anti-glomerular basement membrane antibodies is one of the features of Goodpasture's syndrome. Since the disease has a rapidly progressive course, an early diagnosis is essential. As was already demonstrated in other ELISA methods, 2.45-GHz microwave irradiation can accelerate all kinds of time consuming processes in several laboratory techniques. The application of microwaves in an ELISA for the measurement of anti-GBM antibodies in serum indicated that a considerable time reduction of 75% can be achieved, resulting in a rapid and reliable assay. In addition, microwaves can also have a positive effect on the resolution of that particular ELISA as shown in this study.     

Wegener's granulomatosis presenting with a renal mass

Wegener's granulomatosis (WG) is a systemic disease characterized by necrotizing granulomatous vasculitis that involves primarily the upper and lower respiratory tracts and, in most cases, the kidneys. Kidney involvement in WG presenting as a mass is recognized, but is very rare. We describe a case of WG presenting with upper and lower respiratory symptoms and a renal mass due to both WG and renal cell carcinoma.     

Cytokine and adhesion molecule requirements for lung injury induced by anti-glomerular basement membrane antibody

Acute hemorrhagic lung injury occurs in humans with anti-GBM antibody (Goodpasture's syndrome), however, the mechanism of this injury is still largely unknown. To date, treatment has been confined to steroids and plasmaphoresis. Infusion of anti-GBM antibody into rats caused lung injury with intra-alveolar hemorrhage and intrapulmonary accumulation of neutrophils. Lung injury was dependent on the presence of neutrophils and complement and required both TNF alpha and IL-1. Experiments employing blocking antibodies to adhesion molecules demonstrated requirements for the beta 1 integrin VLA-4, beta 2 integrins LFA-1 and Mac-1, and L-selection. The endothelial cell adhesion molecules, E-selectin and ICAM-1, were also required for the full development of lung injury. Inhibition of TNF alpha or IL-1 or adhesion molecules reduced both lung injury and tissue neutrophil accumulation. Thus, this study underscores cytokine and adhesion molecule requirements for neutrophil mediated injury in lung and kidney caused by anti-GBM, suggesting potential targets for the treatment of Goodpasture's syndrome in humans.     

Th2 responses induce humorally mediated injury in experimental anti-glomerular basement membrane glomerulonephritis

Clinical and endocrinological effects of exemestane (6-methylenandrosta-1,4-diene-3,17-dione; PNU 155971) were evaluated in an open Phase I study. Thirteen postmenopausal women suffering from advanced breast cancer received exemestane in escalating doses over a 12-week period. Starting on 5 mg once daily (o.d.), exemestane was subsequently escalated at 2-week intervals to 10, 25, 50, 100, and 200 mg o.d. Each patient subsequently continued treatment on the highest tolerated dose until time of progression. One patient terminated treatment after 6 days due to diarrhea that was probably not related to drug therapy, although a relationship could not be excluded. Apart from this, no serious side effects were seen during the dose escalation period. Exemestane (10 mg o.d.) caused maximal suppression of plasma estradiol (E2) and estrone (E1) to a mean of 14.6 and 5.8% of pretreatment levels, respectively, whereas 25 mg of exemestane o.d. suppressed estrone sulfate (E1S) to 8.9% of pretreatment levels. No fall in adrenal steroid levels was recorded. Exemestane (5 mg o.d.) suppressed urinary E2 and E1 to a mean of 11.9 and 12.2% of pretreatment levels, respectively. Administering exemestane at doses of 50-200 mg o.d. caused no further suppression of urinary E1, whereas urinary E2 fell to 6-7% of pretreatment levels. Median time to progression was 63 weeks. We conclude that exemestane is a well-tolerated aromatase inhibitor that effectively suppresses plasma and urinary estrogens in postmenopausal patients with breast cancer.     

Survival and vasculitis activity in patients with end-stage renal disease due to Wegener's granulomatosis

BACKGROUND: In patients with end-stage renal disease (ESRD) due to Wegener's granulomatosis, a decrease in vasculitis activity after the development of ESRD, as described in other autoimmune diseases, has been postulated. However, up to now no data in a larger group of patients with Wegener's granulomatosis on chronic dialysis have been available. METHODS: We retrospectively analysed the clinical course of 35 patients with Wegener's granulomatosis and ESRD during chronic dialysis treatment. Diagnosis was based on clinical manifestation, antineutrophil cytoplasmic antibodies and/or histology. RESULTS: During a mean follow-up of 43 months (5-113 months), six patients died, three related to treatment toxicity. The patient survival rates (according to Kaplan-Meier calculation) were 93% after 2 years and 79% after 5 years. Twenty-nine relapses of Wegener's granulomatosis occurred in 17 patients (relapse rate 0.24/patient/year); 2/3 of the relapses were seen during treatment with steroids, 1/6 during cyclophosphamide therapy. The relapses were not related to the dialysis membrane used. Remission or partial remission could be achieved in 93% of the relapses. CONCLUSIONS: The survival of patients on chronic dialysis treatment due to Wegener's granulomatosis was comparable to that of other patient groups with ESRD. The relapse rate was not different from that of non-dialysed patients with Wegener's granulomatosis, and this finding underlines the need for a therapeutic strategy to maintain long-term remission in dialysis-dependent patients, too.     

Wegener's granulomatosis with meningeal involvement: clinic-radiological correlations

INTRODUCTION: Wegener's granulomatosis is a systemic vasculitis which, in its classical form, is characterized by involvement of the superior and inferior respiratory tract and the kidneys. The vasculitis may be multisystemic. Ophthalmic and neurological involvement are common (22% and 54% of those affected respectively). When considering involvement of the nervous system, the commonest finding is peripheral neuropathy, particularly in the form of multiple mononeuritis. Meningeal involvement is exceptional. CLINICAL CASE AND CONCLUSIONS: We present a case of Wegener's granulomatosis with meningeal involvement, studied using CT and MR. The findings using imaging techniques are described, and conditions which should be considered in the differential diagnosis are discussed.     

Expanded T cell populations in patients with Wegener's granulomatosis: characteristics and correlates with disease activity

Patients with Wegener's granulomatosis have a high prevalence of expanded populations of CD4+ and CD8+ T cells bearing different alpha/beta T cell receptors. To elucidate the role of these populations, we studied the phenotypic and functional characteristics of 13 expanded T cell populations in four patients for a period of 35-51 months. The expanded populations generally showed a persistently high expression of the activation markers HLA-DR and CD25. This expression was independent of the activity of the disease. The expanded populations also expressed CD45RO and/or CD45RA and most of them expressed CD57 but not CD28. Analysis of intracellular presence and secretion of IFN-gamma, IL-2, and IL-4 showed that most of the expanded cell populations contained and/or secreted more of these cytokines than the nonexpanded populations, with an especially high expression/secretion of IFN-gamma and IL-2. The expanded populations showed little proliferative response to Con A and OKT3. The proliferative response of the cells was partly restored after preincubation in medium alone. Some of the expanded populations were associated with disease activity, thus suggesting a link between expanded T cells and the disease. The activated status of the expanded populations and the tendency for certain populations to correlate in magnitude with disease activity suggest their involvement in the disease process. The relative stability of these cell populations indicates that the stimulus driving them is persistent, in agreement with the chronicity of the disease.     

Antineutrophil cytoplasmic antibodies in 2 patients with Wegener's granulomatosis

We describe two patients with diffuse alveolar hemorrhage and Wegener s Granulomatosis. In both cases, ANCA were demonstrated. We discuss the profit about ANCA s in the diagnosis and management the systemic vasculitis.     

Experimental induction of glomerulonephritis mediated by anti-glomerular basement membrane and anti-brush border antibodies in a single rat

This report describes induction of nephritis, which was concurrently mediated by [anti-glomerular basement membrane antibody (anti-GBM) and anti-brush border antibody, in the Wistar rat immunized with a solubilized renal antigen (S-RA). The antigen was prepared by digestion of rat cortical tissue with trypsin and pronase. Ouchterlony test using antisera to the rat GBM and brush border showed that the S-RA contained both antigens. From the S-RA the brush border antigen was isolated by affinity chromatography. At the 8th week rats injected with the S-RA showed a linear or combined linear and granular distribution of rat IgG and C3 along the GBM in immunofluorescence. The capillary granular pattern was only observed at the 16th week. In contrast rats injected with the brush border antigen remained in a capillary granular pattern throughout the experimental course. It was suggested that the rat nephritis injected with the S-RA was mediated by the antibodies capable of reacting with at least two different antigens, namely the GBM and the brush border. The possibility was confirmed by demonstrating the coexistence of these two kinds of antibodies in the serum and kidney eluate from the nephritic rats.