Co-occurrence of PLA2R-positive membranous nephropathy without crescents, and PR3-positive eosinophilic granulomatosis with polyangiitis
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Primary membranous nephropathy (PMN) is a common cause of adult nephrotic syndrome, most commonly associated with autoantibodies against M-type phospholipase A2 receptor (PLA2R). Eosinophilic granulomatosis with polyangiitis (EGPA), previously known as Churg-Strauss syndrome, is a rare disorder characterized by asthma, eosinophilia, and multiorgan vasculitis. Here, we report the case of an adult who presented with typical nephrotic syndrome. Renal biopsy revealed PLA2R-positive PMN without crescents. He had a history of asthma, eczema, and eosinophilia, and testing revealed positive serological proteinase 3 (PR3) and antineutrophil cytoplasmic antibody (ANCA). Further skin and bone marrow biopsy revealed histologic eosinophilic infiltration, and a diagnosis of EGPA was made. The renal biopsy revealed a few eosinophils in glomerular capillary lumen and tubulointerstitial. Treatment with a glucocorticoid and cyclophosphamide was initiated. At 32 months after completing therapy, the patient was in complete clinical remission, and the PR3-ANCA result was negative.

Modulation of MMP-2 and MMP-9 in Churg-Strauss syndrome respiratory mucosa: potential monitoring parameters.

Churg-Strauss (CSS) syndrome is rare and of unknown etiology. It is associated with vasculitis, blood eosinophilia and granulomatosis, and affects multiple organs and systems at various stages of the disease. Specific diagnostic and monitoring tests are not yet available. This study aims to assess the changes in MMP-2 and MMP-9 along with the histopathological alterations in two cases of CSS, as possible potential diagnostic and monitoring criteria. Two adult male patients were diagnosed with CSS in the otorhinolaryngology clinic in the University of Palermo, based on multiple clinical and histopathologic criteria. Biopsies of respiratory mucosa were taken after the consent of the patients, processed for routine histopathology and immunohistochemistry as well as quantitative polymerase chain reaction (qPCR). Similar biopsies were also taken from a non- CSS patient. The Assessment of MMP-2 and MMP-9 was performed using both immunohistochemistry and qPCR techniques. Histopathological alterations in the respiratory mucosa were consistent with vasculitis and granulomatous tissue formation, in addition to inflammatory cell infiltration with abundance of eosinophils. Immunohistochemistry assay performed on the samples derived from the two CSS patients showed a relative and remarkable increase of both MMP-2 and MMP-9 compared to controls. Such an increase was consistent with the qPCR results which depicted a significant increase between 20 and 30% for both MMP-2 and MMP-9, respectively. Since the secretion of MMPs is an essential step in angiogenesis, could these enzymatic factors be used as parameters to diagnose or monitor the evolution of CSS? The small number of samples analyzed in this study does not allow us to suggest a general statement correlating the increase in expression of MMP-2 and MMP-9 to the appearance or evolution of vasculitis; it is only speculative.

Antineutrophil cytoplasmic autoantibodies and myeloperoxidase autoantibodies in clinical expression of Churg-Strauss syndrome.

BACKGROUND: The clinical significance of antineutrophil cytoplasmic antibodies (ANCAs) in the phenotypic expression of Churg-Strauss syndrome (CSS) is uncertain. OBJECTIVE: We sought to investigate the relationship between ANCA status and the clinical expression of CSS in a case series derived from the US Food and Drug Administration's adverse events database. METHODS: All cases of CSS reported to the US Food and Drug Administration from 1997 to April 2003 were reviewed. Information about basic demographics, suspect medication use, clinical manifestations, histologic findings, ANCA staining patterns, and the presence of antibodies to myeloperoxidase (anti-MPO) or proteinase 3 (anti-PR3) was recorded when available. RESULTS: There were 93 case reports of CSS with sufficient documentation, including ANCA status. There were 38 (40.9%) of 93 cases with positive ANCA results, of which 15 cases reported a positive ELISA, all of which were positive for anti-MPO. ANCA negativity was associated with an increased proportion of cardiac involvement (risk difference [RD], 38.2%; 95% CI, 25.3% to 51.0%), gastrointestinal involvement (RD, 25.5%; 95% CI, 13.9% to 37.0%), pulmonary infiltrates (odds ratio, 4.9; 95% CI, 1.5-16.2), and the outcome of a life-threatening event or death (RD, 30.9%; 95% CI, 18.7% to 43.1%) when compared with anti-MPO-positive cases. ANCA negativity was associated with a decreased proportion of peripheral neuropathy (odds ratio, 0.3; 95% CI, 0.07-0.9). CONCLUSION: These findings support the hypothesis that the presence or absence of autoantibodies influences the clinical expression and severity of CSS.

Distinct proteinase 3-induced cytokine patterns in Wegener´s granulomatosis, Churg-Strauss syndrome, and healthy controls.

OBJECTIVES: To analyse whether a specific cytokine pattern is elicited in response to the autoantigen proteinase 3 (PR3) in active Wegener's granulomatosis (WG). METHODS: Six-colour flow cytometry was used to analyse cytokine production and surface markers of the total CD4+ T-cell population ex vivo and in PR3-stimulated T-cell lines of patients with active PR3-ANCA-positive WG, PR3-ANCA-negative Churg-Strauss syndrome (CSS), and healthy controls (HC). RESULTS: The cytokine response of the total PB CD4+ T cell population was skewed towards distinct pro-inflammatory cytokine patterns in WG (Th1-type) and CSS (Th17, Th1-/Th2-type). Th2-type as well as Th17 cell populations including Th17/Th1, Th17/Th2 and Th22 cells were elicited in response to PR3 stimulation in WG. In contrast, CSS patients displayed a Th2-type dominated response following PR3 stimulation. CONCLUSIONS: These data suggest that the cytokine response of the total CD4+ T-cell population and PR3-specific cells is influenced by the underlying disorder.

Acute coronary syndrome associated with Churg-Strauss syndrome.

A 41 -year old female patient was admitted with acute onset of dyspnea and chest pain. Previous history revealed asthma, chronic sinusitis and eosinophilic proctitis. Electrocardiogram showed anterior ST-segment elevations and inferior ST-segment depression. Immediate heart catheterization revealed a distally occluded left anterior descending coronary artery, the occlusion being reversible after nitroglycerine. Cardiac magnetic resonance imaging was consistent with perimyocarditis. Hypereosinophilia and IgE elevation were present and Churg-strauss syndrome was diagnosed.

ANCA-associated vasculitis: diagnostic and therapeutic strategy.

Among small-vessel vasculitides, microscopic polyangiitis (MPA), Wegener's granulomatosis (WG), and allergic granulomatous angiitis (AGA) are known collectively as ANCA-associated vasculitis (AAV) because of the involvement of anti-neutrophil cytoplasmic antibodies (ANCA) as the common pathogenesis. Major target antigens of ANCA associated with vasculitis are myeloperoxidase (MPO) and proteinase 3 (PR3). MPO-ANCA is related to MPA and AGA, and PR3-ANCA is the marker antibody in WG. MPO-ANCA-associated vasculitis is more frequent in Japan, whereas PR3-ANCA-associated vasculitis is more common in Europe and USA. ANCA appears to induce vasculitis by directly activating neutrophils. Therefore, no immunoglobulins or complement components are detected in the vasculitis lesions; hence, AAV is called pauci-immune vasculitis (pauci = few/little). Untreated patients with severe AAV with multi-organ involvement have a poor prognosis, which is improved by combination therapy with cyclophosphamide and high-dose corticosteroid. Randomized controlled trials (RCT) regarding induction and maintenance of remission of AAV indicated that the rate of remission induction by the standard regimen is approximately 90% in 6 months, that maintenance of remission can be achieved with oral azathioprine as well as cyclophosphamide, and that methotrexate can be used only for non-renal mild AAV. As these data were obtained mostly in patients positive for PR3-ANCA, caution must be taken in applying these findings to Japanese patients, most of whom are positive for MPO-ANCA. A prospective study is now underway to clarify the effectiveness of the standard regimen in Japanese patients with MPO-ANCA-associated vasculitis. This article describes the diagnostic criteria and the recent evidence-based therapeutic strategy of AAV.

Histologic and immunohistologic study and clinical presentation of ANCA-associated glomerulonephritis with correlation to ANCA antigen specificity.

BACKGROUND: The major antigen specificities of antineutrophil cytoplasmic antibodies (ANCA) are for proteinase 3 (PR3) and myeloperoxidase (MPO). Only a limited number of studies have systematically assessed renal pathology with respect to ANCA antigen specificity. METHODS: The authors evaluated renal biopsy light microscopy and immunofluorescence findings, clinical presentation, and outcome in 135 patients with ANCA-associated vasculitides. RESULTS: Patients were divided into 3 groups: PR3-ANCA (n = 55), MPO-ANCA (n = 74), and ANCA of other specificities (n = 6). The mean duration of renal disease at biopsy was significantly longer in patients with MPO-ANCA than in those with PR3-ANCA (6.9 v 3.0 months). Immunofluorescence results showed mostly pauci-immune glomerulonephritis (n = 129) and rarely diffuse granular glomerular immune deposits suggesting immune complex deposition (n = 6). A focal form of crescentic glomerulonephritis was more frequent (P < 0.001), and glomerular necrosis was more prominent (P = 0.013) in the PR3-ANCA group, whereas diffuse crescentic glomerulonephritis, glomerulosclerosis, and interstitial fibrosis predominated in the MPO-ANCA group (P < 0.001). Extraglomerular vasculitis, present in 22.2%, and chronic vascular lesions indicative of previous vasculitis, present in 11.9% of patients, correlated with systemic involvement. CONCLUSION: The evolution of the pathologic lesions of PR3-ANCA and MPO-ANCA-associated glomerulonephritis seems to be similar. Differences in histopathology could be explained by the observation that in patients with PR3-ANCA, kidney biopsy was performed soon after renal involvement appeared, and focal active lesions were prevalent, whereas in patients with MPO-ANCA, kidney biopsy was done late in the course of the disease, and diffuse chronic sclerotic lesions predominated. Renal extraglomerular small vessel vasculitis appeared to be predictive of systemic involvement.

-463 G/A myeloperoxidase promoter polymorphism is associated with clinical manifestations and the course of disease in MPO-ANCA-associated vasculitis.

Wegener's granulomatosis, microscopic polyangiitis, and Churg Strauss syndrome are forms of systemic vasculitides in which neutrophils and monocyte macrophages infiltrate the walls of small blood vessels, leading to destruction and occlusion. These diseases are associated with autoantibodies directed against granular components of neutrophils and monocytes, i.e., antineutrophil cytoplasmic antibodies (ANCA). The most common target antigens of ANCA in these vasculitides are myeloperoxidase (MPO) and proteinase 3 (PR3). ANCA-stimulated neutrophils injure endothelial cells, a process that is dependent upon the production of reactive oxygen radicals and the release of granular components such as MPO and PR3. Here we investigate whether a common functional MPO promoter polymorphism (-463 G/A) is associated with increased incidence and clinical aspects of ANCA-associated small vessel vasculitis. Genotyping was carried out for 142 patients with ANCA-associated small vessel vasculitis and 129 ethnically matched controls. The GG genotype was found to be associated with an increased risk for MPO-ANCA-associated vasculitis in females (86% GG, P = 0.045), but not males (64% GG, P = 1.0). Interestingly, the MPO A allele is associated with an increased incidence of relapses (P = 0.012) and an earlier age at diagnosis (P = 0.03) of MPO-ANCA-associated vasculitis. Both these associations are specific for MPO-ANCA and are not observed in patients with PR3-ANCA-associated vasculitis. These findings suggest that MPO expression levels influence the disease course of MPO-ANCA-associated vasculitis and further support the view that genetic factors are involved in the pathophysiology of this autoimmune disease.

Relationship between the development of blindness in Churg-Strauss syndrome and anti-myeloperoxidase antibodies.

Occular involvement is infrequent and blindness rare in Churg-Strauss syndrome. We describe a patient with Churg-Strauss syndrome who presented with blindness. This was associated with the appearance of circulating autoantibodies to myeloperoxidase.

Cholinesterase deficiency and the Churg-Strauss syndrome.

We report two patients with the Churg-Strauss syndrome who were found to have decreased cholinesterase activity despite normal phenotypes. Suspicion of abnormal sensitivity to suxamethonium in the first case was raised after prolonged paralysis under anaesthesia. The findings in the second were incidental during the course of intensive care treatment. Both patients received immunosuppressive therapy. Differentiation between the effects of this and the disease process itself cannot be established.