Myeloperoxidase-Antineutrophil Cytoplasmic Antibody-Associated Vasculitis Research Articles

Rapid progression of large intracranial cerebral artery involvement in a patient with myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic necrotizing vasculitis that predominantly affects small vessels of the body. The two most common ANCAs are myeloperoxidase ANCA and proteinase 3 ANCA. Neurological manifestations are frequent in patients with AAV, including peripheral neuropathy, meningitis, and stroke. AAV-associated ischemic stroke usually affects small vessels supplying the white matter or brainstem. This case report details the presentation and treatment course of a 70-year-old man with rapidly progressive multiple intracranial large artery involvement attributed to myeloperoxidase ANCA-associated vasculitis. Despite treatment with high-dose steroids and a rituximab infusion, the patient developed new speech difficulties and respiratory distress, and brain imaging confirmed new stroke lesions with progressive multiple intracranial large cerebral artery involvement. The patient died from SARS-CoV-2 infection 4 months after the diagnosis. This case emphasized the rare presentation of rapidly progressive large vessel involvement in a patient with myeloperoxidase ANCA-associated vasculitis despite active immunotherapy.

Urinary isomorphic red blood cells for the prediction of disease severity and renal outcomes in MPO-ANCA-associated vasculitis: a retrospective cohort study.

Hematuria is common in myeloperoxidaseanti-neutrophil cytoplasmic antibodyassociated vasculitis(ANCA-MPO). Previous studies have mainly focused on urinary dysmorphic red blood cells and few have reported the clinical significance of isomorphic urinaryred blood cells. Therefore, the main aim of this study was to assess the predictive yield of urinary isomorphic red blood cells for disease severity and renal outcomes in patients with ANCA-MPO associated vasculitis. A total of 191 patients with ANCA-MPOassociated vasculitiswith hematuria were retrospectively selectedand were divided into two groups (withisomorphic red blood cells versus dysmorphic red blood cells) according to the percentage of isomorphic red blood cells on urinary sediment analysis. Clinical, biological and pathological data at diagnosis were compared. Patients were followed up for a median of 25months and progression to end-stage kidneydisease and death were regarded as main outcome events. Additionally, univariate and multivariate Cox regression models were used to estimate the risk factors for end-stage kidneydisease. Out of 191 patients, 115 (60%) had ≥ 70% and 76 (40%) had < 30% urine isomorphic red blood cells. Compared with patients in the dysmorphic red blood cell group, patients in the isomorphic red blood cell group had a significantly lower estimated glomerular filtration rate(eGFR) [10.41mL/min (IQR 5.84-17.06) versus 12.53 (6.81-29.26); P = 0.026], higher Birmingham Vasculitis Activity Score [16 (IQR 12-18) versus 14 (10-18); P = 0.005] and more oftenreceived plasma exchange [40.0% versus 23.7% (P = 0.019)] at diagnosis. Kidney biopsies revealed a higher proportion of patients with glomerular basement membrane fracture in the isomorphic red blood cell group [46.3% versus 22.9% (P = 0.033)]. Furthermore, patients with predominant urinary isomorphic red blood cells were more likely to progress to end-stage kidney disease [63.5% versus 47.4% (P = 0.028)] and had a higher risk ofdeath [31.3% versus 19.7% (P = 0.077)]. The end-stage kidney disease-free survival was lower in patients in the isomorphic red blood cell group (P = 0.024). However, urine isomorphic red blood cells ≥ 70% could not predict the presence of end-stage kidney disease in multivariate Cox analysis. Myeloperoxidase-anti-neutrophil cytoplasmic antibodyassociated vasculitis patients with predominant urinary isomorphic red blood cells at diagnosis had more severe clinical manifestations and a higher risk of poor renal outcomes. In this respect, urinary isomorphic red blood cells could be viewed as a promising biomarker of ANCA_MPO vasculitisseverity and progression.

Urinary Matrix Metalloproteinase 7 Activated by Oxidative Stress Predicts Kidney Prognosis in Myeloperoxidase-Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

Aims: Effective and applicable predictors of end-stage kidney disease (ESKD) are needed for patients with myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis (MPO-AAV) and kidney involvement. We investigated whether urinary matrix metalloproteinase-7 (uMMP7) was associated with kidney injury severity and incident ESKD in MPO-AAV. Results: A prospective two-stage study was conducted in 150 patients with newly diagnosed MPO-AAV in two independent cohorts. uMMP7 was measured on the days of initial and repeat kidney biopsies. In stage I, a higher initial uMMP7 level was associated with a lower estimated glomerular filtration rate (eGFR), higher level of proteinuria, and greater extent of kidney pathologic lesions. This elevated uMMP7 protein level is activated and potentially derived from the enhanced kidney production induced by oxidative stress. In stage II, uMMP7 at initial biopsy was independently associated with the incidence of ESKD over 6 years. The higher uMMP7 group (vs. lower) had an adjusted hazard ratio of 3.79 (95% confidence interval [CI], 1.49-6.09) for ESKD in the test cohort. Findings were similar in the validation cohort. A combination of data from the two cohorts revealed that adding uMMP7 into clinical or clinicopathologic models significantly improved risk discrimination for future ESKD. Innovation: An elevated uMMP7 level in MPO-AAV was independently associated with severe kidney injury and incident ESKD. Conclusions: uMMP7 in MPO-AAV improves identification of patients at risk of ESKD and may enable early and optimized therapy to improve outcomes. Antioxid. Redox Signal. 37, 246-256.

Patterns of lung diseases predict survival in patients with MPO-ANCA-associated vasculitis: a single-center retrospective study.

This study aimed to explore differences in clinical features and prognosis among patients with varied myeloperoxidase (MPO) antineutrophil cytoplasmic antibody-associated vasculitis (MPO-AAV) associated lung diseases. Patients with MPO-AAV-associated lung diseases were enrolled in this retrospective cohort study at a single center. Clinical features and laboratory data at the time of diagnosis were compared among patients with various lung disease patterns. Kaplan-Meier and Cox regression analyses were performed to analyze overall survival. A total of 155 patients were finally included and categorized into five groups, as follows: 72 had a usual interstitial pneumonia (UIP) pattern, 40 had non-UIP interstitial pneumonia, 18 had bronchiectasis (BR), 13 had necrotizing granuloma (NG), and 12 had diffuse alveolar hemorrhage (DAH). Among the five groups, patients with DAH had higher dyspnea and hemoptysis frequencies, lower PaO2/FiO2 levels, elevated C-reactive protein levels, and the poorest prognosis. The overall survival (OS) in the DAH group (median OS: 3.2months) was significantly poorer than that in the NG group (median OS: not reached, log rank P < 0.001), the BR group (median OS: not reached, log rank P < 0.001), and the non-UIP IP group (median OS: 61.1months, log rank P = 0.001). The UIP group had significantly more ex-smokers than the other groups (P < 0.001) and the second poorest survival (median OS: 39.1months). The NG group tended to have female predominance, a higher incidence of ENT involvement, less severe renal involvement, and the best survival. After adjusting for multi-model Cox regression analysis, DAH and UIP (hazard ratio: 19.301 and 9.940, respectively, compared with NG) were independent predictors of all-cause mortality. Various patterns of lung disease-associated MPO-AAV may potentially predict patient survival. Key Point • The present study described the clinical and prognostic features of various lung diseases-associated MPO-AAV, indicating the potential prediction for the survival of MPO-AAV patients.

Interstitial lung disease with myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis in elderly patients.

Anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) occurs in elderly people, and patients with anti-myeloperoxidase autoantibodies (MPO-ANCA)-positive AAV are often complicated with interstitial lung disease (ILD). This study aimed to evaluate the age-related clinical features of elderly patients with MPO-ANCA-positive AAV-ILD. This study retrospectively investigated 63 patients with MPO-ANCA-positive AAV-ILD, all of whom were 65years or older at diagnosis. Clinical characteristics, causes of death and survival rates among three groups stratified by age (65-74years, n = 29; 75-79years, n = 18; over 80years, n = 16) were compared. This study also examined the association with severe infections in these patients. Among the three age groups, there were significant differences in sex (P = 0.032), serum Krebs von den Lungen-6 (P < 0.01), and total ground-glass opacity score (P = 0.011). The causes of death were mainly severe infections and complications of ILD. Kaplan-Meier curve analysis showed a significantly lower 5-year survival rate in the oldest group (P < 0.01). Regarding severe infections in these patients, the 5-year cumulative incidence of severe infections was higher in the patients receiving steroid pulse therapy (P = 0.034). The clinical characteristics of MPO-ANCA-positive AAV-ILD differ with age in elderly patients, with age being an important poor prognostic factor in these patients. The administration of steroid pulse therapy is a significant risk factor of severe infection in MPO-ANCA-positive elderly patients with AAV-ILD.

Development of aortic valve stenosis in myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis with renal involvement.

IntroductionDegenerative aortic valve stenosis (AS) is a chronic progressive disease that resembles atherosclerosis development. Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is reportedly associated with accelerated atherosclerosis. This study aimed to examine the development of AS in patients with myeloperoxidase-AAV (MPO-AAV) with renal involvement at more than 1 year after the onset of vasculitis.MethodsWe performed a retrospective review of clinical records of MPO-AAV patients with renal involvement without AS at the onset of vasculitis who were treated in three hospitals and three dialysis clinics.ResultsThe study included 97 MPO-AAV patients with renal involvement and 230 control patients with chronic kidney disease (CKD). Among them, 64 patients had AS. The prevalence rates of AS were 28.9% and 15.7% in MPO-AAV and control patients, respectively (p = 0.006). The multivariable logistic regression analysis showed that MPO-AAV, dialysis dependence, and hypertension were independently associated factors for AS. In MPO-AAV patients, systolic blood pressure was positively significantly associated with AS, whereas glucocorticoid dose of induction therapy was negatively significantly associated. The use of cyclophosphamide tended to be negatively associated with AS. The survival rate was significantly lower for patients with AS than for those without AS.ConclusionsThe AS prevalence rate was significantly higher in MPO-AAV patients at more than 1 year after the onset of vasculitis than in control CKD patients. Therefore, regular monitoring of echocardiography during MPO-AAV treatment is suggested.

Acute Coronary Syndrome Due to Myeloperoxidase-Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

Acute Coronary Syndrome Due to Myeloperoxidase-Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

Supervised Machine Learning for Semi-Quantification of Extracellular DNA in Glomerulonephritis.

Glomerular cell death is a pathological feature of myeloperoxidase anti neutrophil cytoplasmic antibody associated vasculitis (MPO-AAV). Extracellular deoxyribonucleic acid (ecDNA) is released during different forms of cell death including apoptosis, necrosis, necroptosis, neutrophil extracellular traps (NETs) and pyroptosis. Measurement of this cell death is time consuming with several different biomarkers required to identify the different biochemical forms of cell death. Measurement of ecDNA is generally conducted in serum and urine as a surrogate for renal damage, not in the actual target organ where the pathological injury occurs. The current difficulty in investigating ecDNA in the kidney is the lack of methods for formalin fixed paraffin embedded tissue (FFPE) both experimentally and in archived human kidney biopsies. This protocol provides a summary of the steps required to stain for ecDNA in FFPE tissue (both human and murine), quench autofluorescence and measure the ecDNA in the resulting images using a machine learning tool from the publicly available open source ImageJ plugin trainable Weka segmentation. Trainable Weka segmentation is applied to ecDNA within the glomeruli where the program learns to classify ecDNA. This classifier is applied to subsequent acquired kidney images, reducing the need for manual annotations of each individual image. The adaptability of the trainable Weka segmentation is demonstrated further in kidney tissue from experimental murine anti-MPO glomerulonephritis (GN), to identify NETs and ecMPO, common pathological contributors to anti-MPO GN. This method provides objective analysis of ecDNA in kidney tissue that demonstrates clearly the efficacy in which the trainable Weka segmentation program can distinguish ecDNA between healthy normal kidney tissue and diseased kidney tissue. This protocol can easily be adapted to identify ecDNA, NETs and ecMPO in other organs.

Two Cases of Localized Myeloperoxidase-Antineutrophil Cytoplasmic Antibody-Associated Vasculitis Manifested with Intractable Otitis Media

Localized form of myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis (MPO-AAV) in the ear is a rare disease. It manifests as a sudden otalgia with hearing loss accompanied by dizziness and facial nerve palsy. Early diagnosis and treatment with immunosuppressive agents are important to prevent the irreversible progression of sensorineural hearing loss. However, it is hard to diagnose AAV because it can be confused with other common otologic disease, such as acute otitis media or middle ear effusion with labyrinthitis.Here, we report two cases of localized form of MPO-AAV manifesting otologic symptoms that have been properly diagnosed and treated with steroid and immunosuppressant. Key words: Antibodies ㆍ Antineutrophil cytoplasmic ㆍ Otitis media ㆍ Myeloperoxidases

Graves' Disease with Myeloperoxidase Antineutrophil Cytoplasmic Antibody-associated Vasculitis Caused by Antithyroid Drugs —Two Case Reports—

Graves' Disease with Myeloperoxidase Antineutrophil Cytoplasmic Antibody-associated Vasculitis Caused by Antithyroid Drugs —Two Case Reports—

Aortic Aneurysm as a Complication of Myeloperoxidase-antineutrophil Cytoplasmic Antibody-associated Vasculitis.

Myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis (MPO-AAV) does not usually involve large vessels, such as the aorta. However, we experienced three cases having an aortic aneurysm as a complication of MPO-AAV with renal insufficiency. In one patient it involved the onset of descending aortic dissection during treatment for MPO-AAV; another two patients had an abdominal aortic aneurysm at the time of our diagnosis of MPO-AAV. Although we found no pathological evidence in our patients, MPO-AAV might result in large vessel inflammation. Therefore, we suggest that patients with MPO-AAV should be examined by computed tomography scan to check for the presence of an aortic aneurysm.

Clinical analysis of patients with myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis.

This prospective study analyzed the clinical characteristics of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis and explored the relationship between MPO-ANCA and clinical manifestations of the associated vasculitis in 132 p-ANCA and MPO-ANCA-positive patients (average age, 62.3 ± 14.8 years) who were initially diagnosed with ANCA-associated vasculitis. The p-ANCA and MPO-ANCA levels in peripheral blood were detected in all patients. Among these, 128 (97%) had microscopic polyangiitis (MPA), 3 (2.3%) had granulomatous polyangiitis, and 1 (0.7%) had eosinophilic granulomatous vasculitis. The average time of diagnosis was 10.2 ± 18 months; only 14 (10.6%) patients were diagnosed within 1 month. The main organs involved and the corresponding number of patients were: renal, 95 (72%); lung, 89 (67.4%); joints, 35 (26.5%); heart, 26 (19.7%); peripheral nerve, 23 (17.4%); skin rash, 14 (10.6%); and CNS, 13 (9.8%). Older patients were more likely to show lung involvement in the early disease stage, whereas the joints were involved mostly in the younger patients. The p-ANCA levels (mean titers, 1:60) were not correlated with disease activity and extent of organ involvement, and the MPO-ANCA levels were positively correlated with disease activity, but had no correlation with the extent of organ involvement. MPO-ANCA vasculitis is a common occurrence in China; it mainly involves the elderly and presents as clinical manifestations of MPA. However, the multiple organ damage is not specific leading to delay in diagnosis. MPO-ANCA may play a pathogenic role in the associated vasculitis, and the diverse clinical manifestations might be related with the different characteristics of MPO-ANCA.

Clinical trial for Japanese patients with myeloperoxidase anti-neutrophil cytoplasmic antibody-associated vasculitis: the JMAAV study

In view of the marked difference in epidemiology of myeloperoxidase/proteinase 3 anti-neutrophil cytoplasmic antibody (MPO/PR3-ANCA)-associated vasculitis between Japan and Western countries, a prospective, open-label, multi-center trial (Japanese Patients with MPO-ANCA-Associated Vasculitis; JMAAV) was performed to evaluate the usefulness of severity-based treatment in Japanese patients with newly diagnosed MPO-ANCA-associated vasculitis. Among the 47 patients enrolled and prescribed predefined therapies, 42 achieved remission within 6 months (89%), 5 died (11%), and 1 developed end-stage renal disease (2%). Disease relapsed in 8 of the 42 patients with remission during the 18-month follow-up period (19%). The remission and death rates were comparable to several previous clinical trials performed in Western counties. Relapse and severe infection, however, appeared to be more frequent than in previous trials, and therefore should be investigated further in future trials. Subsidiary analysis was also performed using samples from these patients, and a new serum biomarker for microscopic polyangiitis and a novel gene expression profile of peripheral blood to predict response to treatment were found by proteomic and transcriptomic analysis, respectively.

AP-VAS 2012 case report: a case of myeloperoxidase antineutrophil cytoplasmic antibody-positive microscopic polyangiitis with rapidly progressive glomerulonephritis and hearing loss.

A 74-year-old Japanese woman was admitted to our hospital because of fever, fatigue, and hearing loss associated with vertigo. She had a 1-year history of hearing impairment that got worse gradually and had been treated as otitis media with effusion, but without remarkable improvement. After admission, she developed renal dysfunction associated with hematuria and proteinuria. Laboratory tests showed leukocytosis and elevated C-reactive protein. Myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) was elevated, but proteinase-3 antineutrophil cytoplasmic antibody (PR3-ANCA) was negative. Renal biopsy revealed pauci-immune focal necrotizing glomerulonephritis with crescents. She was diagnosed as having MPO-ANCA-associated polyangiitis. After treatment with 500mg methylprednisolone applied intravenously for 3days, followed by 40mg prednisolone administered orally, renal function recovered completely. Her hearing also improved. Although otolaryngological symptoms are common in PR3-ANCA associated vasculitis, hearing loss is a rare manifestation of MPO-ANCA associated vasculitis (MPO-AAV). Our case suggests that AAV should be considered in the differential diagnosis of hearing loss.

A case of ANCA-associated vasculitis with glomerular eosinophilic infiltration: a possible pathogenic implication

We present a 58-year-old male patient with myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis with rapidly progressive glomerulonephritis. He failed to fulfill the common American College of Rheumatology criteria for eosinophilic granulomatosis with polyangiitis and was tentatively diagnosed with microscopic polyangiitis. Kidney biopsy showed pauci-immune crescentic necrotizing glomerulonephritis with neutrophilic and eosinophilic infiltration. Previous reports implicate eosinophils in the pathogenesis of this disease. Therefore, this case suggests that infiltrated eosinophils as well as neutrophils might play roles in the development of tissue injury in systemic vasculitis.

A New Vasculitis Activity Score for Predicting Death in Myeloperoxidase-Antineutrophil Cytoplasmic Antibody-Associated Vasculitis Patients

Background/Aims: Myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-positive microscopic polyangiitis patients with renal involvement have been shown to have a progressive clinical course. In this study, we compared the clinical utility of the Japanese Vasculitis Activity Score (JVAS) with the Birmingham Vasculitis Activity Score (BVAS) for predicting death in patients with MPO-ANCA-associated renal involvement. Methods: Sixty-nine patients with MPO-ANCA-associated vasculitis with renal involvement (22 males and 47 females, age 69.8 ± 8.7 years) were enrolled in this study. We retrospectively investigated which score was better for predicting the poor prognosis of patients. Results: The mortality rate of the patients within 2 years after disease onset was 33% (23/69). JVAS was not correlated with BVAS. Univariate logistic regression analysis for death showed that the odds ratio (OR) of JVAS was statistically significant (OR 1.76, 95% confidence interval, CI, 1.29–2.41, p < 0.001), while that of BVAS was not (OR 1.07, 95% CI 0.98–1.16, p = 0.14). Moreover, a multivariate model showed that JVAS was an independent determinant of death (OR 1.59, 95% CI 1.12–2.25, p = 0.009). The area under the receiver operating characteristic curve for JVAS was 0.778, which was significantly larger (p = 0.02) than that for BVAS (0.586). The estimated optimal cut-off point of JVAS for the prediction of death was 5. At this point, the sensitivity was 82.6% and the specificity was 60.9%. Conclusion: We demonstrated that compared with BVAS, JVAS was a simpler and more reliable measure for predicting death in patients with MPO-ANCA-associated vasculitis with renal involvement.

Regulation of myeloperoxidase‐specific T cell responses during disease remission in antineutrophil cytoplasmic antibody–associated vasculitis: The role of Treg cells and tryptophan degradation

T lymphocytes have been implicated in the pathogenesis of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Patients with myeloperoxidase (MPO) antineutrophil cytoplasmic antibody (ANCA) experience relapses less frequently than those with proteinase 3 ANCA, suggesting greater immune regulation. This study was undertaken to investigate MPO-specific T cell reactivity during disease remission and the factors regulating their responsiveness. MPO-specific T cells were quantified by enzyme-linked immunospot assay with additional Treg cell depletion or exogenous interleukin-2. Serum tryptophan and its metabolites were measured. In vivo blockade of indoleamine 2,3-dioxygenase (IDO) was performed, and its effect on MPO reactivity was assessed. During disease remission, MPO-specific interferon-gamma-producing T cell frequencies were comparable with those found in healthy controls and significantly lower than those found in patients with acute disease. CD4+CD25+ regulatory cells did not play a role in maintaining these low MPO-specific T cell frequencies, since depletion of Treg cells did not augment MPO-specific responses, and FoxP3 levels were diminished in patients compared with controls. Treg cell function, however, was comparable in patients and controls, suggesting numerical rather than functional deficiency. We found diminished serum tryptophan levels and elevated levels of its metabolite kynurenine in patients with MPO AAV as compared with controls. To confirm the effect of tryptophan degradation on MPO responses in vivo, we inhibited degradation in MPO-immunized WKY rats and found greater immune responsiveness to MPO and a tendency to more severe glomerulonephritis. Our findings indicate that MPO-specific T cell frequencies are regulated during disease remission in association with tryptophan degradation. The tryptophan regulatory pathway is induced during active disease and persists during disease remission.

Clinical Characteristics of Myeloperoxidase Antineutrophil Cytoplasmic Antibody-Associated Vasculitis Caused by Antithyroid Drugs

The clinical characteristics of myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitis caused by antithyroid drugs are still unclear because most reports describe only a small number of patients. The objective was to analyze a large number of patients with MPO-ANCA-associated vasculitis to determine the time of onset, the drug and dose taken, the clinical symptoms, the relationship between the clinical symptoms and the MPO-ANCA titer, and the incidence. We analyzed 92 patients in whom the adverse reaction of MPO-ANCA-associated vasculitis was reported to Chugai Pharmaceutical, a company that markets antithyroid drugs. Of the 92 patients, 41 (44.6%) had single-organ failure, 32 (34.8%) had two-organ failure, 13 (14.1%), had three-organ failure, and two (2.2%) had four-organ failure. The number of organs involved was unknown in the other four patients (4.3%). The median time of onset was 42 months (range, 1-372 months) after starting drug treatment. The median dose at onset of MPO-ANCA-associated vasculitis was 15 mg/d (range, 2.5-45 mg/d) for methimazole and 200 mg/d (50-450 mg/d) for propylthiouracil. The severity and number of organs involved were not correlated with the MPO-ANCA titer. The incidence was between 0.53 and 0.79 patients per 10,000, and the ratio of the estimated incidences for methimazole and propylthiouracil was 1:39.2. The time of onset of MPO-ANCA-associated vasculitis and the dose at onset varied. The severity and number of organs involved were not correlated with the MPO-ANCA titer, indicating a need for vigilance even when the MPO-ANCA titer is only weakly positive.