Risk factors for serious infections and infection-related mortality in patients with microscopic polyangiitis: Multicentre REVEAL cohort study.

OBJECTIVE: Infections are a critical concern for patients with microscopic polyangiitis (MPA). This study aimed to identify the risk factors associated with serious infections (SIs) and infection-related mortality in patients with MPA, as well as the effect of glucocorticoid (GC) dose tapering on these outcomes. METHODS: This multicentre, retrospective, and observational study utilised data from a cohort of patients with MPA in Japan [Registry of Vasculitis Patients to Establish REAL World Evidence (REVEAL) cohort]. Patients were categorised based on the occurrence of SIs or infection-related deaths, and various characteristics were compared among the groups. RESULTS: Among 182 patients, 66 (36.2%) experienced 129 SIs and 27 (14.8%) developed infection-related deaths. Advanced age, elevated C-reactive protein (CRP) levels, and higher ratio of the GC dose at 3 months to the initial dose were identified as independent risk factors for SIs. Older age was also associated with infection-related deaths. Furthermore, the cumulative incidence of infection-related deaths was significantly higher in patients with a higher ratio of the GC dose at 24 months to the initial dose. CONCLUSION: Older age, elevated CRP levels, and slower GC dose tapering predispose patients to SIs and infection-related deaths. Strategies, such as rapid GC dose tapering, are anticipated to mitigate the risk of infections.

Epidemiology, clinical features, risk factors, and outcomes in anti-glomerular basement membrane disease: A systematic review and meta-analysis.

Anti-glomerular basement membrane (GBM) disease is a small-vessel vasculitis that represents the most aggressive form of autoimmune glomerulonephritis. The study aimed to investigate the prevalence, clinical characteristics, risk factors, and outcomes of anti-GBM disease through a systematic review and meta-analysis involving 47 studies with 2830 patients. The overall incidence of anti-GBM disease ranged from 0.60 to 1.79 per million population per annum. In rapidly progressive glomerulonephritis and crescentic glomerulonephritis, the pooled incidence rates were 8.0% and 12.8%, respectively. The pooled prevalence rates of anti-GBM antibodies, antineutrophil cytoplasmic antibodies (ANCA), and lung hemorrhage were 88.8%, 27.4%, and 32.6%, respectively. Patients with combined ANCA positivity demonstrated a prognosis comparable to those patients with only anti-GBM antibodies, though with differing clinical features. The pooled one-year patient and kidney survival rates were 76.2% and 30.2%, respectively. Kidney function on diagnosis and normal glomeruli percentage were identified as strong prognostic factors. This study represents the first comprehensive meta-analysis on anti-GBM disease, providing insights into its management. However, caution is warranted in interpreting some results due to the observational nature of the included studies and high heterogeneity.

Verification, implementation and harmonization of automated chemiluminescent immunoassays for MPO- and PR3-ANCA detection.

OBJECTIVES: Antineutrophil cytoplasmic antibody (ANCA) testing assists clinicians diagnose ANCA-associated vasculitis (AAV). We aimed to verify and harmonize chemiluminescent immunoassays for the detection of myeloperoxidase (MPO)- and proteinase 3 (PR3)-ANCA. METHODS: An in-house ELISA, a capture ELISA, and a chemiluminescent assay QUANTA Flash on a BIO-FLASH analyzer were used to detect MPO- and PR3-ANCA in sera from 39 patients with AAV, 55 patients with various non-AAV, and 66 patients with connective tissue diseases. The results of the assays were evaluated, and their clinical performance was assessed. The precision and linearity of the QUANTA Flash assays were determined, and likelihood ratios (LRs) for AAV at diagnosis were calculated. RESULTS: The precision and linearity of the QUANTA Flash assays were confirmed. Overall agreement between 97.5 and 98.8 % and Cohen's kappa coefficients between 0.861 and 0.947 were observed for the results of the QUANTA Flash assays and ELISAs. The diagnostic sensitivity, specificity, and ROC analysis of the assays for AAV were statistically similar (in-house ELISA 89.7 %, 95.0 %, and 0.937; capture ELISA 92.3 %, 98.3 %, and 0.939; and QUANTA Flash 89.7 %, 95.9 %, and 0.972). For the QUANTA Flash assay results, the interval-specific LRs for AAV at diagnosis were: 0-8 CU had LR 0.08, 8-29 CU had LR 1.03, 29-121 CU had LR 7.76, 121-191 CU had LR 12.4, and >191 CU had LR ∞. CONCLUSIONS: The QUANTA Flash MPO and PR3 assays provide precise and consistent results and have comparable clinical utility for AAV. The calculated LRs were consistent with published LRs, confirming the utility of LRs for harmonization of ANCA results.

Analysis of treatment outcomes in patients with antineutrophil cytoplasmic antibody-associated vasculitis on rituximab therapy.

Objectives: This study aimed to analyze a group of patients with severe and refractory antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) managed with rituximab and to report on treatment outcomes. Patients and methods: A total of 78 patients (41 females, 37 males; mean age: 50.1±13.4 years; range, 18 to 76 years) with AAV on rituximab treatment were included in the single-center, retrospective study conducted between 2009 and 2018. The diagnosis was established based on the 1990 classification criteria of the American College of Rheumatology and the definitions of vasculitis of Chapel Hill Consensus Conference. Laboratory and immunological tests were conducted. Disease activity was determined through the Birmingham Vasculitis Activity Score. Results: Rituximab was preferred over cyclophosphamide in 37 patients and used as a second-line therapy after cyclophosphamide in 41 cases. Rituximab treatment showed favorable outcomes with regard to serum creatinine levels, proteinuria, and hematuria, as well as in cases of isolated lung involvement. Nearly half of patients with pulmonary renal syndrome also improved, with 22.2% achieving remission. ANCAs were positive in 85.9% of patients at the onset of rituximab treatment and became negative in 82% of the positive cases. Adverse events were rare and included infusion reactions (one case of reactivation of a herpes zoster infection and one case of allergic reaction). Conclusion: Rituximab is an efficient and safe therapeutic option in patients with AAV who are difficult to treat, have insufficient response, or have not tolerated other treatments.

The Role of Neutrophils in ANCA-Associated Vasculitis: The Pathogenic Role and Diagnostic Utility of Autoantibodies.

Recent years have brought progress in understanding the role of the neutrophil, dispelling the dogma of homogeneous cells mainly involved in the prime defence against pathogens, shedding light on their pathogenic role in inflammatory diseases and on the importance of antineutrophil-cytoplasmic antibodies' pathogenic role in ANCA-associated vasculitides vasculitis (AAV). Myeloperoxidase (MPO) and proteinase 3 (PR3) expressed in neutrophil granulocytes are the most common targets for ANCAs and contribute to the formation of MPO-ANCAs and PR3-ANCAs which, released to the bloodstream, become an excellent diagnostic tool for AAV. In this study, we focus on increasing the clinical and experimental evidence that supports the pathogenic role of ANCAs in AAV. Additionally, we discuss the diagnostic utility of ANCAs for disease activity and prognosis in AAV. Understanding the central role of ANCAs in AAV is crucial for advancing our knowledge of these complex disorders and developing targeted therapeutic strategies in the era of personalized medicine.

Bowman capsule rupture in children with myeloperoxidase-antineutrophil cytoplasmic antibody-associated glomerulonephritis predicts poor renal survival.

Background: Recent developments indicated that Bowman capsule rupture (BCR) is observed in antineutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis (AAGN). We aimed to explore the relationship between BCR and clinical manifestations, pathological changes, and prognosis in children with myeloperoxidase (MPO)-AAGN. Methods: A total of 56 children with MPO-AAGN were divided into BCR (+) and BCR (-) groups according to the status of Bowman's capsule. Clinical and histological features and renal outcomes were compared, and the predictive value of BCR for end-stage kidney disease (ESKD) of MPO-AAGN was evaluated. Results: After retrospective analysis of the data, 24 children (42.9%) were found to have BCR. The results showed that BCR positively correlated with intrarenal immune cell infiltrates, obsolescence and crescents in glomeruli, tubulointerstitial inflammation, tubulitis, and tubular atrophy negatively correlated with normal glomeruli and immunoglobulin G deposition in the kidney. The clinical features and kidney pathological changes were more severe in the BCR (+) group than BCR (-) group, and the renal survival rate was significantly poorer in the BCR (+) group than BCR (-) group (χ2 = 5.45, p = 0.02). Moreover, estimated glomerular filtration rate (≤15 mL/min/1.73 m2), BCR and ANCA renal risk score (ARRS) were independent risk factors for the development of ESKD in children with MPO-AAGN. After combining BCR with the Berden classification and ARRS, our data suggested that the Berden classification + BCR and ARRS + BCR showed better predictive values for ESKD than those of the Berden classification and ARRS, respectively. Conclusion: BCR is an important pathological lesion that correlates with severe clinical manifestations, pathological changes, and poor prognosis in children with MPO-AAGN.

A Rare Case of Allergic Bronchopulmonary Aspergillosis Progressing to Cardiac Tamponade in the Al Qassim Region of Saudi Arabia.

Allergic bronchopulmonary aspergillosis (ABPA) is a condition characterized by an exaggerated response of the immune system (a hypersensitivity response) to the fungus Aspergillus. Aspergillus-associated pericarditis leading to pericardial tamponade is rare. In our case, we presented a case of a 22-year-old female asthmatic patient with no other medical conditions who presented to the emergency department (ED) complaining of severe chest tightness and shortness of breath. Echocardiography revealed significant pleural and pericardial effusion consistent with cardiac tamponade. Both pleural and pericardial fluids were hemorrhagic. Four months later, she presented to the ED with chief complaints of shortness of breath and a cough lasting two days. She was admitted as a case of asthma exacerbation. In the following months, when the patient visited the pulmonology outpatient clinic, the doctors recommended for specific IgE test. Allergen-specific IgE testing was positive for A. fumigatus to confirm the presence of ABPA. As we rolled out other causes of cardiac tamponade, we link the development of cardiac tamponade secondary to an underlying Aspergillus infection. We report this case with the aim of improving clinical knowledge regarding probable causes of cardiac tamponade in patients with asthma, which may facilitate the establishment of early diagnosis and treatment protocols.

An atypical presentation of granulomatosis with polyangiitis: A case report.

Granulomatosis with polyangiitis (GPA) is a systemic vasculitis that is associated with antineutrophil cytoplasmic antibodies (c-ANCA). It classically presents with sinonasal, pulmonary and renal involvement. We are presenting a case of a 32-year-old male who presented with septal perforation, crusting and nasal obstruction. He had been operated on twice for sinonasal polyposis. Relevant investigations revealed that he was actually suffering from GPA. The patient was started on remission induction therapy. A combination of methotrexate and prednisolone was started with a 2-weekly follow-up. The patient had experienced his symptoms for 2 years before presentation. This case highlights the importance of correlating ENT and pulmonary symptoms to reach the correct diagnosis.

Central and Peripheral Nervous System Complications of Vasculitis Syndromes from Pathology to Bedside: Part 2-Peripheral Nervous System.

PURPOSE OF REVIEW: Peripheral nervous system vasculitides (PNSV) are a heterogeneous group of disorders with a clinical subset that may differ in prognosis and therapy. We provide a comprehensive update on the clinical assessment, diagnosis, complications, treatment, and follow-up of PNSV. RECENT FINDINGS: Progress in neuroimaging, molecular testing, and peripheral nerve biopsy has improved clinical assessment and decision-making of PNSV, also providing novel insights on how to prevent misdiagnosis and increase diagnostic certainty. Advances in imaging techniques, allowing to clearly display the vessel walls, have also enhanced the possibility to differentiate inflammatory from non-inflammatory vascular lesions, while recent histopathology data have identified the main morphological criteria for more accurate diagnosis and differential diagnoses. Overall, the identification of peculiar morphological findings tends to improve diagnostic accuracy by defining a clearer boundary between systemic and non-systemic neuropathies. Therefore, the definition of epineurium vessel wall damage, type of vascular lesion, characterization of lymphocyte populations, antibodies, and inflammatory factors, as well as the identification of direct nerve damage or degeneration, are the common goals for pathologists and clinicians, who will both benefit for data integration and findings translation. Nevertheless, to date, treatment is still largely empiric and, in some cases, unsatisfactory, thus often precluding precise prognostic prediction. In this context, new diagnostic techniques and multidisciplinary management will be essential in the proper diagnosis and prompt management of PNSV, as highlighted in the present review. Thirty to fifty percent of all patients with vasculitis have signs of polyneuropathy. Neuropathies associated with systemic vasculitis are best managed according to the guidelines of the underlying disease because appropriate workup and initiation of treatment can reduce morbidity. Steroids, or in severe or progressive cases, cyclophosphamide pulse therapy is the standard therapy in non-systemic vasculitic neuropathies. Some patients need long-term immunosuppression. The use of novel technologies for high-throughput genotyping will permit to determine the genetic influence of related phenotypes in patients with PNSV.

Adverse reaction to metal debris with accompanying gout and amyloid deposits in hip arthroplasty.

Adverse reaction to metal debris (ARMD) is a known complication of metal-on-metal hip arthroplasty. There has been one previously reported case of ARMD with concomitant gout in the setting of a hip arthroplasty. We report a case of ARMD with accompanying monosodium urate crystals as well as amyloid deposition in the hip of a patient who had undergone a metal-on-metal hip arthroplasty. This is the only published case to date of these 3 conditions co-existing, although it is possible that the incidence is higher since these require special diagnostic tests that are not routinely performed. It is postulated that these entities are biochemically associated with each other rather than being purely coincidental.

Multiple brain infarctions and endomyocarditis in ANCA-negative eosinophilic granulomatosis with polyangiitis.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a small vessel necrotizing vasculitis characterized by asthma and eosinophilia. Ischemic stroke is a rare complication of the disease. We herein report a case involving a 77-year-old woman with sinusitis who developed embolic stroke and splenic infarctions. Laboratory tests revealed hypereosinophilia and elevated troponin-T and N-terminal pro-brain natriuretic peptide. Antineutrophil cytoplasmic antibodies (ANCA) studies were negative. Skin biopsy showed infiltration of eosinophils into the arterial walls. These clinicopathological findings led to the diagnosis of EGPA. We also found the evidence of endomyocarditis as revealed by multimodality cardiac imaging. The patient underwent continuous immunosuppressive and anticoagulation therapy, and the infarctions did not recur. This report highlights the importance of histologically proven vasculitis with eosinophil infiltration and careful examination for cardiac involvement, especially in ANCA-negative patients.

Improvement of indirect immunofluorescence technique to detect antineutrophil cytoplasmic antibodies and its impact on test positivity rate

The indirect immunofluorescence (IIF) technique for antineutrophil cytoplasmic antibodies (ANCA) detection is subject to substantial differences across laboratories. This study aimed to assess the impact of improvements in the IIF-ANCA technique on the positivity rate of ANCA tests. A cross-sectional study was performed with serum samples from patients with ANCA-associated vasculitis (AAV), autoimmune hepatitis (AIH), and ulcerative colitis (UC). A paired analysis was performed for IIF-ANCA results using the traditional method and a modified protocol after a series of specific adjustments in the technique based on the protocol of IIF-ANCA test performed at a nation-wide private laboratory in Brazil. ANCA specificity was assessed by ELISA for anti-proteinase 3 (PR3) and anti-myeloperoxidase (MPO) antibodies. Sixty-one patients were evaluated. The positivity rate of IIF-ANCA tests at disease presentation performed at the University reference laboratory was 32.3% in AAV, AIH, and UC patients, whereas the positivity rates of IIF-ANCA and ELISA tests in other laboratories were 75.0 and 72.7%, respectively. After modifications in the IIF-ANCA technique, there was a significant increase in the positivity rate (14.8 vs 34.3%; P=0.0002) and in median titers [1/40 (1/30-1/160) vs 1/80 (1/40-1/80); P=0.0003] in AAV, AIH, and UC patients. UC had the highest increment in positive results from 5.3 to 36.8%. There was poor agreement between MPO- or PR3-ANCA and both IIF-ANCA techniques. In conclusion, modifications in the IIF-ANCA protocol led to a significant improvement in its positivity rate and titers.

CD206+CD68+ mono-macrophages and serum soluble CD206 level are increased in antineutrophil cytoplasmic antibodies associated glomerulonephritis.

BACKGROUND: Antineutrophil Cytoplasmic Antibodies (ANCA) associated glomerulonephritis (AGN) is a group of autoimmune diseases and mono-macrophages are involved in its glomerular injuries. In this study, we aim to investigate the role of CD206+ mono-macrophages in AGN. METHODS: 27 AGN patients (14 active AGN, 13 remissive AGN) together with healthy controls (n = 9), disease controls (n = 6) and kidney function adjusted controls (n = 9) from Department of Nephrology, Ruijin hospital were recruited. Flow cytometry was used to study proportion of CD206+ cells in peripheral blood. Immunohistochemistry for CD206 staining was performed and CD206 expression was scored in different kidney regions. Serum soluble CD206 (sCD206) was measured by enzyme-linked immunosorbent assay (ELISA). We also generated murine myeloperoxidase (MPO) (muMPO) ANCA by immunizing Mpo-/- mice. Mouse bone marrow-derived macrophages (BMDMs) from wild C57BL/6 mice and peripheral blood mononuclear cell (PBMC) derived macrophages from healthy donors were treated with MPO ANCA with or without its inhibitor AZD5904 to investigate the effects of MPO-ANCA on CD206 expression. RESULTS: The proportion of peripheral CD206+CD68+ cells in active AGN patients were significantly higher than that in remissive patients (p < 0.001), healthy controls (p < 0.001) and kidney function adjusted controls (p < 0.001). Serum sCD206 level in active AGN patients was higher than that in healthy controls (p < 0.05) and remissive patients (p < 0.01). Immunohistochemistry showed CD206 was highly expressed in different kidney regions including fibrinoid necrosis or crescent formation, glomeruli, periglomerular and tubulointerstitial compartment in active AGN patients in comparison with disease controls. Further studies showed MPO ANCA could induce CD206 expression in BMDMs and PBMC derived macrophages and such effects could be reversed by its inhibitor AZD5904. CONCLUSION: ANCA could induce CD206 expression on mono-macrophages and CD206+ mono-macrophages are activated in AGN. CD206 might be involved in the pathogenesis of AAV and may be a potential target for the disease.

A case of infective endocarditis mimicking antineutrophil cytoplasmic antibody-associated vasculitis.

Infective endocarditis (IE) is not a common disease, but it remains a serious condition. Antineutrophil cytoplasmic antibodies (ANCA) are often positive in IE, and discrimination between IE and ANCA-associated vasculitis is important because misdirected selection of therapy can lead to catastrophic consequences. We report a case of IE mimicking ANCA-associated vasculitis in which we were able to make a correct diagnosis and perform treatment. This case suggests that it is important to consider IE as a differential diagnosis in ANCA-positive patients. Learning objective: Antineutrophil cytoplasmic antibodies (ANCA) are associated with primary systemic vasculitis. However, ANCA have also been described in other conditions and infective endocarditis (IE) was considered an important cause of ANCA.Discrimination between IE and ANCA-associated vasculitis is important, although it is sometimes difficult. We report a case of IE mimicking ANCA-associated vasculitis. ANCA-positive patients with nonspecific symptoms should be suspected of having IE, checked for heart murmurs, and tested by echocardiography and blood cultures.

Autoimmune Diseases in Patients With Myotonic Dystrophy Type 2.

Introduction: Myotonic dystrophy type 2 (DM2) is a rare autosomal dominant multisystemic disease with highly variable clinical presentation. Several case reports and one cohort study suggested a significant association between DM2 and autoimmune diseases (AIDs). Aim: The aim of this study is to analyze the frequency and type of AIDs in patients with DM2 from the Serbian DM registry. Patients and Methods: A total of 131 patients with DM2 from 108 families were included, [62.6% women, mean age at DM2 onset 40.4 (with standard deviation 13) years, age at entering the registry 52 (12.8) years, and age at analysis 58.4 (12.8) years]. Data were obtained from Akhenaten, the Serbian registry for DM, and through the hospital electronic data system. Results: Upon entering the registry, 35 (26.7%) of the 131 patients with DM2 had AIDs including Hashimoto thyroiditis (18.1%), rheumatoid arthritis, diabetes mellitus type 1, systemic lupus, Sjogren's disease, localized scleroderma, psoriasis, celiac disease, Graves's disease, neuromyelitis optica, myasthenia gravis, and Guillain-Barre syndrome. At the time of data analysis, one additional patient developed new AIDs, so eventually, 36 (28.8%) of 125 DM2 survivors had AIDs. Antinuclear antibodies (ANAs) were found in 14 (10.7%) of 63 tested patients, including 12 without defined corresponding AID (all in low titers, 1:40 to 1:160). Antineutrophil cytoplasmic antibodies (ANCAs) were negative in all 50 tested cases. The percentage of women was significantly higher among patients with AIDs (82.9% vs. 55.2%, p <0.01). Conclusion: AIDs were present in as high as 30% of the patients with DM2. Thus, screening for AIDs in DM2 seems reasonable. Presence of AIDs and/or ANAs may lead to under-diagnosis of DM2.

Propylthiouracil-Induced Antineutrophil Cytoplasmic Antibodies-Associated Vasculitis with Renal and Lung Involvement.

Propylthiouracil (PTU)-induced antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a rare and heterogeneous disease. Moreover, optimal treatment is still lacking. We described the case of a 44-year-old lady with underlying Graves' disease who had cough, blood-streaked sputum, and impaired renal function. A strongly positive anti-myeloperoxidase antibody (>200 U/mL) along with pauci-immune glomerulonephritis and pulmonary hemorrhage resulted in the diagnosis of PTU-induced AAV, given that the patient had been on PTU for 3 years. PTU withdrawal, therapeutic plasma exchanges, and oral cyclophosphamide provided favorable clinical and biochemical outcomes. She remained well on azathioprine 50 mg daily as maintenance therapy and clinically euthyroid with carbimazole 2.5 mg daily. The effective treatment for drug-induced ANCA vasculitis remains controversial, but rapid withdrawal of the offending medication should be the mainstay of treatment. In severe drug-induced ANCA vasculitis with pulmonary hemorrhage and/or life-threatening organ involvement such as kidney failure requiring dialysis, therapeutic plasma exchange with immunosuppressants is often required. In this case, we have shown that patient achieved remission after therapeutic plasma exchange with cyclophosphamide in the acute stage of treatment and remained symptom-free with azathioprine in the maintenance phase of treatment for 24 months.

Glomerular IgA Deposition and Serum Antineutrophil Cytoplasmic Antibody Positivity in a Child With Dystrophic Epidermolysis Bullosa: Case Report and Literature Review.

Patients with epidermolysis bullosa (EB) could develop significant urological complications, such as hydroureteronephrosis, renal amyloidosis and IgA nephropathy (IgAN). Here, we presented a 12-year-old boy carrying pathogenic COL7A1 mutation with diagnosis of dystrophic epidermolysis bullosa (DEB). The patient had concomitant gross hematuria and proteinuria. Pathological examinations and immunostaining of renal biopsy showed glomeruli with mesangial hypercellularity and deposition of IgA, which were indicative of IgAN. Interestingly, serological evaluation showed antineutrophil cytoplasmic antibody (ANCA) directed against myeloperoxidase and proteinase 3. Treatment with glucocorticoid, immunosuppressants, angiotensin-converting enzyme inhibitor and antibiotics efficiently improved hemato-proteinuria, and ANCAs became negative as well. This case of DEB presented a unique collection of clinical manifestations and pathological alterations. IgAN and serum positive ANCA were possibly associated with sustained infection secondary to DEB, and can be managed by empirical treatment for primary IgAN.

Antineutrophil Cytoplasm Antibody-Associated Vasculitides Valvular Impairment: Multicenter Retrospective Study and Systematic Review of the Literature.

OBJECTIVE: While myocardial impairment is a predictor of poor prognosis in antineutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV), little is known about valvular involvement. This study aims at describing the clinical presentation, management, and outcome of endocarditis associated with AAV. METHODS: We conducted a multicenter retrospective study in centers affiliated with the French Vasculitis Study Group. We included patients with granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), or eosinophilic GPA with endocardial impairment. A systematic review was then performed through PubMed, Embase, and Cochrane Library from inception up to September 2020. RESULTS: The retrospective cohort included 9 patients (82%) with GPA, 1 (9%) with MPA, and 1 (9%) with unclassified AAV. Clinical presentation included acute valvular insufficiency (n = 7, 64%), cardiac failure (n = 3, 27%), dyspnea (n = 3, 27%), and no symptoms (n = 2, 18%). The aortic valve was the most frequently affected (n = 8/10, 80%), and vegetations were noted in 4 of 10 patients (40%). Six patients (55%) underwent surgical valvular replacement. No death from endocarditis was reported. The systematic review retrieved 42 patients from 40 references: 30 (71%) had GPA, 21 (50%) presented with vegetations, the aortic valve (n = 26, 62%) was the most frequently involved. Valvular replacement was required in 20 cases (48%) and 5 patients (13%) died from the endocarditic impairment. CONCLUSION: Endocarditis is a rare and potentially life-threatening manifestation of AAV. Acute valvular insufficiency may lead to urgent surgery. Implementing transthoracic echocardiography in standard assessment at baseline and follow-up of AAV might reduce the delay to diagnosis and allow earlier immunosuppressive treatment before surgery is needed.

The Role of Sural Nerve Biopsy in the Diagnosis of Vasculitis.

OBJECTIVE: The diagnostic yield of sural nerve biopsy (SNB) in vasculitis is uncertain. Our aim was to document relevant characteristics of patients undergoing SNB in the investigation of vasculitis; determine the diagnostic yield; relate positive biopsy findings to patient demographic, laboratory, and clinical variables; and to calculate the rate of surgical complications. METHODS: Patients with suspected vasculitis that underwent SNB as part of diagnostic evaluation at academic medical centers in Sweden and the United Kingdom were identified by searching local pathology databases and clinic registers. A structured review of medical case records and pathology reports was conducted. Histological findings were categorized as definite, probable, or no vasculitis in accordance with the 2015 Brighton Collaboration reinterpretation and update of the Peripheral Nerve Society guidelines for vasculitic neuropathy. Definite and probable findings were considered positive for vasculitis. RESULTS: Ninety-one patients that underwent SNB were identified (45% female). Forty (44%) patients showed histological evidence of vasculitis: 14 definite and 26 probable. A concomitant muscle biopsy conducted in 10 patients did not contribute to the diagnostic yield. Positive antineutrophil cytoplasmic antibody test, organ involvement other than the nervous system, and a longer biopsy sample were associated with a positive biopsy. The reported surgical complication rate was 15%. CONCLUSION: SNB of sufficient length is a useful procedure to confirm a diagnosis of vasculitis.