Sterile Endocarditis and Splenic Infarct: A Rare Masquerading Presentation of Granulomatosis With Polyangiitis in a Patient With Pulmonary Aspergillosis.

Granulomatosis with polyangiitis (GPA) is a rare multisystem disease characterized by vasculitis affecting small vessels, resulting in the formation of necrotising granulomata, primarily affecting the lungs, the upper respiratory tract, and kidneys. Almost all patients have upper and lower respiratory involvement; up to 85% of patients with GPA develop kidney disease within two years of diagnosis. Cutaneous, neurological, and ocular manifestations are also seen with varying frequencies. However, cardiac manifestations of the disease are rare and scarcely reported in the literature. Here, we report a case of a 65-year-old female with an initial diagnosis of pulmonary aspergillosis based on the presence of septate hyphae branching at acute angles on lung biopsy and elevated serum galactomannan, who, over the following months, developed a multitude of issues such as myocardial infarction, sterile endocarditis, splenic infarction, and heart block, as well as the challenges faced in establishing a diagnosis and managing its complications.

Progression to ANCA-associated vasculitis in patients with idiopathic interstitial pneumonia and positive ANCA.

OBJECTIVE: This study explored the development of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and its risk factors in patients with idiopathic interstitial pneumonia (IIP) and positive ANCA results. METHODS: Data of patients diagnosed with IIP with positive ANCA results at a single tertiary center in South Korea were retrospectively reviewed from January 2013 to August 2023. Cox regression analysis was performed to identify variables associated with AAV occurrence following IIP diagnosis. Kaplan-Meier curves were employed to investigate the relationship between autoantibodies and the occurrence of AAV. RESULTS: In a cohort of 154 IIP-diagnosed patients with positive ANCA results but without AAV, 10.4 % of them eventually developed AAV. The AAV and non-AAV groups did not significantly differ by sex, age, smoking status, urinalysis, or chest computed tomography findings. All the patients who subsequently developed AAV were anti-myeloperoxidase (MPO) positive, while 48.8 % of the non-AAV patients were anti-MPO positive (P < 0.001). Rheumatoid factor (RF) positivity differed significantly (62.5 % vs. 29.2 %, P = 0.007) between the AAV and non-AAV groups. Multivariate Cox regression and Kaplan-Meier analyses revealed RF (HR 4.02; P = 0.004) and anti-MPO (HR 38.10; P < 0.001) positivity as risk factors associated with AAV occurrence. CONCLUSION: Approximately 10 % of ANCA-positive IIP patients developed AAV after an IIP diagnosis. Anti-MPO or co-occurring positive RF poses a significant risk for subsequent AAV occurrence. This emphasizes the importance of careful monitoring in patients with high-risk antibody profiles, even if the complete features of AAV are not present at IIP diagnosis.

Propylthiouracil-Induced Anti-Neutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis Presenting with Multiple Sterile Abscesses, Mononeuritis Multiplex, and Splenic Vein Thrombosis: A Case Report and Literature Review.

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) represents a rare group of disorders, that traditionally includes diseases like granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA), and microscopic polyangiitis (MPA). However, AAV can also be triggered by medications such as propylthiouracil (PTU). This article focuses on the subset of drug-induced AAV. We examine how certain medications, notably PTU, can provoke an AAV response, detailing the pathophysiological mechanisms and clinical implications. A 72-year-old female being treated with PTU presented with bilateral hand abscesses, generalized weakness, and frequent falls. Despite initial treatments, her condition worsened, prompting consideration of AAV secondary to PTU. Following appropriate diagnostic procedures and initiation of treatment, including steroids, heparin, and rituximab, the patient showed significant improvement. PTU-induced AAV is a serious, albeit rare, side effect characterized by anti-neutrophil cytoplasmic autoantibodies, with the potential for varied organ involvement and generally a better prognosis than primary AAV. The atypical presentation in this case underscores the importance of clinician vigilance and awareness, ensuring timely diagnosis and appropriate management of this complex condition.

Use of mesna prophylaxis in patients with cyclophosphamide-treated ANCA-associated vasculitis: cross-sectional survey of practitioners.

BACKGROUND: There may be some diversity in the practice of co-prescribing 2-mercaptoethane sodium sulfonate (mesna) with cyclophosphamide (CYC) for ANCA-associated vasculitis (AAV). OBJECTIVES: To assess the practice of prescribing mesna prophylaxis for CYC-treated patients with AAV. METHODS: We invited authors of publications on AAV referenced in MEDLINE over the previous 10 years to participate in an anonymous online survey. Respondents were eligible if they were involved in CYC treatments for AAV. The survey asked about the characteristics of the respondents and their practice in using CYC and mesna to treat AAV and the underlying rationale. We compared 18 variables between mesna prescribers and their counterparts to identify factors associated with mesna use. RESULTS: In total, 139 eligible individuals completed the survey. The participants were from 34 countries and were essentially physicians (98%). Overall, 68%, 19% and 13% of respondents prescribed mesna systematically, never, or on a selective basis. As compared with never/selective-prescribers, systematic-prescribers were more often ≤ 39 years old (P = 0.008), more often used intermittent pulse therapy as the exclusive/predominant CYC administration scheme (P < 0.001), were more frequently based in France/Germany/Italy than in England/United States (P < 0.001), and more often indicated adherence to local standards (P = 0.003) or (inter)national guidelines for AAV (P < 0.001) as a rationale for their mesna practice. Never/selective-prescribers more commonly reported that their mesna prescription pattern had changed as compared with their former practice (P < 0.001). CONCLUSIONS: Systematic co-prescription of mesna is the prevailing practice for CYC treatments for AAV. The practice seems to involve practicability considerations and differs between generations.

Accelerated atherosclerosis in Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis: case report.

Accelerated atherosclerosis has been identified as a complication of multiple autoimmune diseases, among which Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis stands out. We describe the case of a 60-year-old patient with a history of hypertension, diabetes mellitus, and chronic kidney disease of unknown etiology, who presented two acute coronary syndromes with only a six-month difference. Rapid progression of coronary involvement was evidenced, along with increased markers of inflammatory response, usual interstitial pneumonia on tomography, and positive anti-myeloperoxidase antibodies (anti-MPO), leading to the diagnosis of microscopic polyangiitis (MPA). In these cases, timely diagnostic suspicion is crucial, as early treatment significantly impacts the course and prognosis of the disease.

A case of rapid avacopan-induced liver injury in pediatric granulomatosis with polyangiitis.

Children with anti-neutrophil cytoplasmic antibody-associated vasculitis benefit immensely from avacopan as it reduces the requirement for steroids. However, descriptions of adverse drug reactions in children are lacking, and the dosage and follow-up intervals are unclear. A 10-year-old boy with initial granulomatosis and polyangiitis presented with diffuse pulmonary hemorrhage. Rituximab and 30 mg avacopan were administered twice daily as induction therapy following methylprednisolone pulse therapy. However, sudden liver function test abnormalities were observed on day 31 of avacopan treatment, despite liver enzyme levels being within the normal range 5 days earlier. A drug-induced lymphocyte stimulation and various infectious disease tests yielded negative results. Discontinuation of rituximab and avacopan resulted in improved liver function; no change in the Birmingham Vasculitis Activity Score during liver function test abnormalities was observed. Avacopan-associated abnormalities in liver function tests suggest that drug-induced liver injury may occur rapidly in children, and appropriate dosing strategies should be reconsidered.

Diagnostic delays in systemic vasculitides.

Systemic vasculitides are among the less common disorders encountered in routine rheumatology practice. The low incidence and heterogeneous presentation at onset can potentially lead to delayed diagnosis. Not recognizing these in the early phase may prove detrimental, as some vasculitis may progress to a catastrophic course with major morbidity or mortality. The causes of diagnostic delay may vary among different types of vasculitis and may also be disease-, patient-, or physician-related. Disease-related factors include the myriad presentations with diverse and non-specific symptoms, mimicking other conditions like infections. In addition, some forms have prolonged prodromal phases before evident organ damage. Limited awareness among healthcare professionals, particularly outside rheumatology, and a lack of readily available diagnostic tools contribute to missed diagnoses. Delays in seeking care due to non-specific symptoms or lack of access to specialist care can worsen outcomes. The economic burden also increases with delayed diagnosis and damage accrual when the disease remains unrecognized or untreated for prolonged periods. Although the causes of vasculitis are numerous, including secondary causes, in this review, we focus on diagnostic delays in primary vasculitides and suggest potential steps to identify and treat these diseases early. These include educating both healthcare professionals and the public about the signs and symptoms of vasculitis; expanding the rheumatology workforce and facilitating timely referrals; implementing readily available and reliable tests for early detection; and streamlining care and diagnostic pathways. Such measures have the potential to improve the overall outcomes of the disease, with prolonged remission, minimal damage accrual, and improved quality of life.

Protective effect of astaxanthin on ANCA-associated vasculitis.

OBJECTIVE: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a systemic autoimmune disease characterized by inflammation and fibrinoid necrosis of medium and small vessels, and its pathogenesis is closely related to inflammation and oxidative stress. Astaxanthin (ATX) is a carotenoid with anti-inflammatory, antioxidant, and immunomodulatory effects. We hypothesized that ATX could play a role in AAV treatment. This study aimed to investigate whether ATX has a protective effect against AAV and to elucidate its regulatory mechanism. METHODS: In vitro experiments, neutrophils isolated from healthy people were treated with ATX or not and cultured with serum from myeloperoxidase (MPO) -ANCA-positive patients and healthy persons. The levels of IL-6 and TNF-α in neutrophil culture supernatant before and after stimulation were measured. Neutrophil extracellular traps (NETs) and intracellular reactive oxygen species (ROS) in neutrophils were detected after stimulation. In vivo study, experimental autoimmune vasculitis (EAV) rat models were established and then treated with ATX via intragastric administration for 6 consecutive weeks. Urinary erythrocytes, urinary proteins, and serum creatinine were detected and HE staining was performed to assess renal injury in rats. Lung hemorrhage was observed by gross dissection and microscopic Prussian blue staining. The level of serum MPO-ANCA was detected. Serum IL-6, TNF-α, superoxide dismutase (SOD), and glutathione peroxidase (GSH-px) in rats were measured to explore the effects of ATX on oxidative stress and inflammation in EAV rats. The deposition of MPO in kidney and lung of rats was detected by immunohistochemistry. RESULTS: ATX significantly inhibited neutrophil secretion of inflammatory factors IL-6 and TNF-α. ATX reduced the elevated levels of ROS in neutrophils stimulated by serum from AAV patients and alleviated the release of NETs. ATX administration was observed to reduce the degree of hematuria, proteinuria, and glomerular crescent formation in EAV rats. The degree of pulmonary hemorrhage was significantly reduced. Besides, the serum levels of IL-6 and TNF-α were attenuated, and antioxidant SOD and GSH-px increased in serum. Pathological results showed that MPO deposition was decreased in lung and kidney tissues after ATX treatment. CONCLUSION: ATX could ameliorate the organ damages in EAV rats. It could serve as a hopeful therapy for AAV by its anti-inflammatory and anti-oxidative feature as a unique nature carotenoid.

Mortality and cardiovascular risk in vasculitis ANCA. Importance of hypertension and renal function. Experience from southern Spain / Mortalidad y riesgo cardiovascular en vasculitis ANCA. Importancia de la hipertension y funcion renal. Experiencia del sur de España

Background: Cardiovascular disease (CVD) is one of the principal causes of death in antineutrophil cytoplasmic antibody-(ANCA)-associated vasculitis (AAV). Objectives: To evaluate the mortality and it's causes and CVD and its vascular risk factors (VRFs) in AAV patients in Andalusia. Methods: A multicenter cohort of 220 AAV patients followed-up from 1979 until June 2020 was studied in Andalussia, south of Spain. The information, including socio-demographic and clinical data was recorded retrospectively through chart review. Data was analysed using Chi2, ANOVA and Cox proportional hazards regresion as uni and multivariate test with a 95% confidence interval (CI). Results: During a mean ± standard deviation follow-up of 96.79 ± 75.83 months, 51 patients died and 30 presented at least one CVE. Independent prognostic factors of mortality were age (HR 1.083, p=0.001) and baseline creatinine (HR 4.41, p=0.01). Independent prognostic factors of CVE were age [hazard ratio (HR) 1.042, p=0.005] and the presence of hypertension (HTN) six months after diagnosis (HR 4.641, p=0.01). HTN, diabetes and renal failure, all of these important VRFs, are more prevalent in AAV patients than it is described in matched general population. Conclusions: Age and baseline renal function, but not CVEs, are predictors of mortality and age and early HTN are independent predictors for having a CVE. CVD screening in AAV patients is demanded.(AU)

Introducción: La enfermedad cardiovascular (ECV) es una de las principales causas de muerte en las vasculitis asociadas a anticuerpos anticitoplasma de neutrófilos (ANCA) (VAA). Objetivos: Evaluar la mortalidad y sus causas, entre ellas la ECV y sus factores de riesgo vascular (FRV) en pacientes con VAA en Andalucía. Métodos: Se estudió una cohorte multicéntrica de 220 pacientes con VAA seguidos desde 1979 hasta junio de 2020 en Andalucía. La información, incluidos los datos sociodemográficos y clínicos, se registró retrospectivamente a través de la revisión de historias clínicas. Los datos se analizaron mediante Chi2, ANOVA y regresión de riesgos proporcionales de Cox de forma uni y multivariante con un intervalo de confianza (IC) del 95%. Resultados: Durante un seguimiento medio y desviación estándar de 96,79 ± 75,83 meses, 51 pacientes fallecieron y 30 presentaron al menos un ECV. Los factores pronósticos independientes de mortalidad fueron la edad (HR 1,083, p=0,001) y la creatinina basal (HR 4,41, p=0,01). Los factores pronósticos independientes de ECV fueron la edad [hazard ratio (HR) 1,042, p=0,005] y la presencia de hipertensión arterial (HTA) seis meses después del diagnóstico (HR 4,641, p=0,01). La prevalencia de HTA, diabetes e insuficiencia renal fue elevada o muy elevada en comparación con la población general emparentada, todos FRCV determinantes para el pronóstico de estos pacientes. Conclusiones: La edad y la función renal basal son predictores de mortalidad y la edad y la HTA de aparición precoz son predictores independientes de tener ECV. Se recomienda el cribado de FRCV en pacientes con vasculitis ANCA.(AU)

Variation in approaches to acute ANCA-associated vasculitis in Australia and New Zealand: rituximab, plasma exchange and glucocorticoids.

BACKGROUND: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare autoimmune disease which is managed by a range of specialities. There are limited data on treatment practices in Australia and New Zealand. AIMS: To understand current patterns of acute AAV treatment in Australia and New Zealand. METHODS: An online survey was conducted between July and October 2022 investigating physicians' views on the management of AAV, focusing on induction therapy. The survey contained questions pertaining to access to treatment and responses to clinical management scenarios. Eosinophilic granulomatosis with polyangiitis was not included. A chi-squared test of independence was performed for statistical analysis. RESULTS: From a total of 55 responses, plasma exchange was difficult to access for 44% of respondents, more so in rural centres, and they also had difficulty accessing infusion centres. New Zealand clinicians had more difficulty accessing rituximab, with only 44% reporting easy access compared with Australian clinicians (93%). With clinical management scenarios, there was variation in the dosing regimen of glucocorticoids and initiation of plasma exchange, with 42% of respondents prescribing a glucocorticoid regimen different from the standard of care, the 'reduced-dose' arm of the Plasma Exchange and Glucocorticoids for the Treatment of ANCA-Associated Vasculitis trial. The choice of cyclophosphamide or rituximab for induction therapy was based on patient characteristics and medical history. CONCLUSIONS: There is substantial variation in approaches to the acute management of AAV in Australia and New Zealand, including differences in resource availability. This variation in care demonstrates the need to implement current practice guidelines and institute contemporary monitoring of AAV management, to achieve best patient outcomes.

Detailed tracking of antigen and antibody levels during coronavirus disease 2019 treatment in an immunosuppressed patient with anti-neutrophil cytoplasmic autoantibody-associated vasculitis.

A 67-year-old woman with anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis was not vaccinated against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was on multiple immunosuppressive drugs. She was hospitalized because of interstitial shadowing in the lungs and diagnosed with persistent coronavirus disease 2019 (COVID-19). Despite treatment with a recombinant monoclonal antibody and antivirals, her symptoms persisted and she lacked a specific antibody response. She tested negative for SARS-CoV-2 antigen after the second antiviral treatment, and a subsequent chest radiograph showed improvement. However, the antibody levels did not change. This case highlights the importance of careful monitoring of the SARS-CoV-2 antigen and antibody levels during COVID-19 treatment in patients with immunosuppression.

CD36 regulates macrophage and endothelial cell activation and multinucleate giant cell formation in anti neutrophil cytoplasm antibody vasculitis.

OBJECTIVE: To investigate CD36 in ANCA-associated vasculitis (AAV), a condition characterized by monocyte/macrophage activation and vascular damage. METHODS: CD36 expression was assessed in AAV patients and healthy controls (HC). The impact of palmitic acid (PA) stimulation on multinucleate giant cell (MNGC) formation, macrophage, and endothelial cell activation, with or without CD36 knockdown, was examined. RESULTS: CD36 was overexpressed on AAV patients' monocytes compared to HC, regardless of disease activity. AAV patients exhibited elevated soluble CD36 levels in serum and plasma and PR3-ANCA patients' monocytes demonstrated increased MNGC formation following PA stimulation compared to HC. PA stimulation of macrophages or endothelial cells resulted in heightened CD36 expression, cell activation, increased macrophage migration inhibitory factor (MIF) production, and c-Myc expression, with attenuation upon CD36 knockdown. CONCLUSION: CD36 participates in macrophage and endothelial cell activation and MNGC formation, features of AAV pathogenesis. AAV treatment may involve targeting CD36 or MIF.

Investigation of Clinical Features and Association between Vascular Endothelial Injury Markers and Cytomegalovirus Infection Associated with Thrombotic Microangiopathy in Patients with Anti-Neutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis: Case-Based Research.

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) can occasionally trigger thrombotic microangiopathy (TMA). Cytomegalovirus (CMV) may be reactivated during intensive immunosuppressive therapy for AAV and cause TMA. Therefore, we aimed to evaluate the clinical features of and the association between vascular endothelial injury markers and TMA due to CMV in patients with AAV. A 61-year-old female was diagnosed with AAV and severe kidney injury. Immunosuppressive therapy gradually improved her symptoms and laboratory findings. However, 2 weeks after induction therapy initiation, she exhibited altered consciousness, a significant decrease in platelet count, and hemolytic anemia, resulting in a TMA diagnosis. Plasma exchange did not improve TMA findings and routine screening test revealed CMV infection. Ganciclovir injection improved the infection and TMA findings. Consequently, we diagnosed her with CMV-induced TMA. Both AAV and CMV may induce severe vascular endothelial injury, potentially leading to TMA development. CMV-induced TMA should be considered when TMA develops during induction therapy against AAV. Moreover, of the three serum markers of vascular injury-serum sulfatides, soluble thrombomodulin, and pentraxin 3-serum sulfatides may be associated with the development of TMA, and a high level of soluble thrombomodulin may be associated with the development of CMV viremia during the clinical course of AAV.

Mortality and cardiovascular risk in vasculitis ANCA. Importance of hypertension and renal function. Experience from southern Spain.

BACKGROUND: Cardiovascular disease (CVD) is one of the principal causes of death in antineutrophil cytoplasmic antibody-(ANCA)-associated vasculitis (AAV). OBJECTIVES: To evaluate the mortality and it's causes and CVD and its vascular risk factors (VRFs) in AAV patients in Andalusia. METHODS: A multicenter cohort of 220 AAV patients followed-up from 1979 until June 2020 was studied in Andalussia, south of Spain. The information, including socio-demographic and clinical data was recorded retrospectively through chart review. Data was analysed using Chi2, ANOVA and Cox proportional hazards regresion as uni and multivariate test with a 95% confidence interval (CI). RESULTS: During a mean ± standard deviation follow-up of 96.79 ± 75.83 months, 51 patients died and 30 presented at least one CVE. Independent prognostic factors of mortality were age (HR 1.083, p=0.001) and baseline creatinine (HR 4.41, p=0.01). Independent prognostic factors of CVE were age [hazard ratio (HR) 1.042, p=0.005] and the presence of hypertension (HTN) six months after diagnosis (HR 4.641, p=0.01). HTN, diabetes and renal failure, all of these important VRFs, are more prevalent in AAV patients than it is described in matched general population. CONCLUSIONS: Age and baseline renal function, but not CVEs, are predictors of mortality and age and early HTN are independent predictors for having a CVE. CVD screening in AAV patients is demanded.

Incidence of anti-neutrophil cytoplasmic antibody-associated renal vasculitis: a retrospective study in rural and regional Victoria, Australia.

BACKGROUND: The epidemiology of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) varies worldwide. Previous Australian studies described a higher incidence of AAV in rural areas; however, this has not yet been investigated in Victoria. AIMS: To calculate the incidence of AAV in rural and regional Victoria and characterise the demographics and clinical outcomes of this cohort. METHODS: We performed a retrospective review of patients with newly diagnosed AAV confirmed on renal biopsy at Bendigo Health between 2013 and 2021. Cases were classified according to the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology criteria. Local disease incidence was calculated using Estimated Resident Population data for our catchment, the Loddon Mallee region. RESULTS: Twenty-eight cases of new AAV were identified; 17 were classified as microscopic polyangiitis (MPA) and the remainder as granulomatosis with polyangiitis (GPA). The median age at diagnosis was 68 years (interquartile range (IQR): 59-77). The incidence per million person-years was 9.3 for AAV overall (95% CI: 6.2-13.5), 5.7 for MPA (95% CI: 3.3-9.1) and 3.7 for GPA (95% CI: 1.8-6.6). With a median follow-up time of 3.3 years (IQR: 1.9-5.6), one-quarter of patients relapsed (n = 7, 25%), and six required ongoing renal-replacement therapy (21%). CONCLUSIONS: The calculated incidence of AAV in rural and regional Victoria is not higher than the reported incidence in most urban Australian cohorts. This study may underestimate the true local disease incidence as only patients with renal vasculitis were included.

Eosinophilic granulomatosis with polyangiitis, asthma as the first symptom, and subsequent Loeffler endocarditis: A case report.

BACKGROUND: Eosinophilic granulomatosis with polyangiitis (EGPA), formerly known as Churg-Strauss syndrome, is a rare form of anti-neutrophil cytoplasmic antibody-associated vasculitis characterized by asthma, vasculitis, and eosinophilia. CASE SUMMARY: We report an atypical case of EGPA in a 20-year-old female patient. Unlike previously reported cases of EGPA, this patient's initial symptom was asthma associated with a respiratory infection. This was followed by Loeffler endocarditis and cardiac insufficiency. She received treatment with methylprednisolone sodium succinate, low molecular weight heparin, recombinant human brain natriuretic peptide, furosemide, cefoperazone sodium/sulbactam sodium, and acyclovir. Despite prophylactic anticoagulation, she developed a large right ventricular thrombus. EGPA diagnosis was confirmed based on ancillary test results and specialty consultations. Subsequent treatment included mycophenolate mofetil. Her overall condition improved significantly after treatment, as evidenced by decreased peripheral blood eosinophils and cardiac markers. She was discharged after 17 d. Her most recent follow-up showed normal peripheral blood eosinophil levels, restored cardiac function, and a reduced cardiac mural thrombus size. CONCLUSION: This case illustrates the swift progression of EGPA and underscores the significance of early detection and immediate intervention to ensure a favorable prognosis.

Late Onset of Rivaroxaban-Associated Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis.

Although anti-thyroid drugs (ATDs) are the most common cause of drug-associated anti-neutrophil cytoplasmic antibody (ANCA) vasculitis (AAV), many other classes of drugs can lead to drug-associated AAV. We present a unique case of rivaroxaban-associated AAV. A 76-year-old female with a past medical history of atrial fibrillation on rivaroxaban presented with fatigue, bilateral lower extremity purpura, and hemoptysis to an outside hospital. Investigations revealed a positive cytoplasmic-ANCA (c-ANCA) titer of 1:320 and a positive anti-myeloperoxidase (anti-MPO), and negative perinuclear-ANCA (p-ANCA) and anti-proteinase 3 (anti-PR3). In addition, chest imaging demonstrated bilateral ground-glass opacities which raised suspicion for diffuse alveolar hemorrhage (DAH). A lung biopsy revealed acute and ongoing DAH with focally active capillaritis and characteristic pathological findings, which strongly suggested that was likely secondary to rivaroxaban. Rivaroxaban was discontinued, and the patient received pulses of intravenous glucocorticosteroids and rituximab. Her symptoms improved. She continued immunosuppressive therapy with rituximab for 2 years. She presented to our hospital for a second opinion regarding the discontinuation of rituximab, and we decided to discontinue rituximab. After discontinuation, the patient remained stable after 1.5 years of follow-up and did not have any relapses. This is a unique case of rivaroxaban-associated AAV. Clinicians should consider drug-associated AAV in all patients who present with an atypical clinical presentation and/or pathological findings of AAV. Given the broad and rapidly increasing use of novel anticoagulants, it is important to raise awareness of this potential complication. Prompt discontinuation of the drug and initiation of immunosuppressant treatment in severe cases may be lifesaving.

Immune-mediated Necrotizing Myopathy in a Patient with Microscopic Polyangiitis: A Case Report.

We herein report a case of immune-mediated necrotizing myopathy (IMNM) in a patient with microscopic polyangiitis (MPA). A 77-year-old Japanese woman presented with a 2-day history of proximal muscle weakness and myalgia, with elevated serum creatinine kinase (CK) levels. Findings of a muscle biopsy were compatible with IMNM; however, anti-SRP and anti-HMGCR antibodies were negative. She also had peripheral neuropathy with elevated serum MPO-ANCA titers, leading to a diagnosis of MPA. IMNM can be a pathological result of MPA muscle involvement.

Serum Complement C4 Levels Are a Useful Biomarker for Predicting End-Stage Renal Disease in Microscopic Polyangiitis.

This study aimed to evaluate the risk factors for end-stage renal disease (ESRD) in microscopic polyangiitis (MPA). In total, 74 patients with MPA were enrolled, and we compared the baseline clinical characteristics and disease activity between MPA patients who have progressed to ESRD and those without ESRD to select predictive factors for ESRD. Out of 74 patients, 12 patients (16.2%) had ESRD during follow-up. Serum C4 levels were significantly higher in MPA patients who have progressed to ESRD than in those without ESRD (p = 0.009). Multivariate analyses revealed that high serum creatinine levels (odds ratio (OR) 4.4, 95% confidence interval (CI) 1.25-15.5) and high serum C4 levels (OR 1.24, 95% CI 1.03-1.49) were risk factors for ESRD. Using receiver operating characteristic analysis, the cut-off value for initial serum C4 levels and serum creatinine levels were 29.6 mg/dL and 3.54 mg/dL, respectively. Patients with MPA with a greater number of risk factors (serum C4 levels > 29.6 mg/dL and serum creatinine levels > 3.54 mg/dL) had a higher ESRD progression rate. Serum C4 levels were significantly positively correlated with serum creatinine levels and kidney Birmingham vasculitis activity score (p = 0.02 and 0.04, respectively). These results suggest that serum C4 levels are useful tools for assessing renal disease activity and prognosis in MPA.