Cardiac Tamponade as a Complication of Microscopic Polyangiitis: A Case Associated With a COVID-19 mRNA Vaccine.

Widespread uptake of the coronavirus disease 2019 (COVID-19) vaccinations has become the world's championed defense against the global pandemic. Four vaccines have been either approved or authorized for emergency use by the FDA, and at this time, over 13 billion doses of these vaccines have been administered around the world. Unfortunately, uncommon and sometimes unforeseen side effects such as small-vessel vasculitis have been reported. In this case report, we present a 74-year-old woman with a history of hypertension, type 2 diabetes mellitus, and hypothyroidism who developed microscopic polyangiitis (MPA) following the second dose of the Pfizer-BioNTech mRNA vaccine for COVID-19. The diagnosis of MPA was confirmed by a kidney biopsy. The autoimmune condition progressed to pericardial effusion and eventual cardiac tamponade, which is occasionally seen in the disease. In this patient's case, we suspect there to be a temporal association between mRNA COVID-19 vaccination and the development of MPA. Direct causation has not been determined.

Anti-neutrophil Cytoplasmic Antibody-Associated Vasculitis With Periaortitis That Developed After mRNA COVID-19 Vaccination.

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has caused a global pandemic resulting in many deaths. As a result, vaccines to prevent the onset of coronavirus disease 2019 (COVID-19) have been developed and have demonstrated high efficacy in large-scale clinical trials. Adverse events that develop within a few days after vaccination are common, such as fever, malaise, body aches, and headaches, and have become widely known as transient reactions. However, as COVID-19 vaccines are administered worldwide, several studies have highlighted that long-term side effects associated with vaccines against SARS-CoV-2 may include serious adverse events. There has been an increase in reports of COVID-19 vaccinations being associated with the onset of autoimmune diseases, such as anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis. This is a report of ANCA-associated vasculitis with periaortitis following the second dose of COVID-19 mRNA vaccination, in which a 56-year-old man developed numbness and pain in his lower extremities three weeks after COVID-19 vaccination. Following the onset of sudden abdominal pain, a fluorodeoxyglucose-positron emission tomography scan revealed periaortic inflammation. Serum myeloperoxidase (MPO)-ANCA levels were significantly elevated, and renal biopsy revealed pauci-immune crescentic glomerulonephritis. Treatment with steroids and cyclophosphamide alleviated abdominal pain and numbness in the lower limbs, resulting in a decrease in MPO-ANCA titers. The side effects of COVID-19 vaccination are still unclear. This report has indicated that side effects associated with vaccines against COVID-19 may include ANCA-associated vasculitis. However, a causal relationship between COVID-19 vaccination and the development of ANCA-associated vasculitis has not yet been clearly demonstrated. COVID-19 vaccination will continue internationally, so it is necessary to accumulate similar case reports in the future.

An unusual form of kidney injury without glomerulonephritis in microscopic polyangiitis: a case report.

BACKGROUND: Microscopic polyangiitis (MPA), a kind of antineutrophil cytoplasmic autoantibody associated vasculitis (AAV), predominantly affects small-sized vessels. MPA is a significant cause of the pulmonary-renal syndrome. Pauci-immune necrotizing and crescentic glomerulonephritis is the typical renal histological feature of AAV. Tubulointerstitial lesions may occur and mostly form with inflammatory cell infiltration in the interstitium. However, a few cases reported only tubulointerstitial involvement without glomerular lesions in patients with MPA. CASE PRESENTATION: We present an MPA case, a 70-year-old male patient diagnosed with acute kidney injury accompanying the dialysis requirement. Only acute tubulointerstitial nephritis was revealed in kidney biopsy without evidence of glomerular injury. Also, interstitial pulmonary fibrosis was determined on computerized tomography, and myeloperoxidase antineutrophil cytoplasmic autoantibody was positive. Consequently, we have considered the main diagnosis as MPA. We did not prefer a standard tubulointerstitial nephritis treatment regimen due to the presence of life-threatening systemic vasculitis. Treatment was established like crescentic glomerulonephritis. Induction therapy consisted of pulse steroid, cyclophosphamide, and plasmapheresis. Unfortunately, severe SARS-CoV-2 infection caused death during induction therapy in this case. CONCLUSIONS: The lack of glomerular injury and solely interstitial inflammation is atypical regarding AAV involvement in the kidney. This diversity might be initially considered as only a simple histological elaboration. However, it is a significant entity for guiding the treatment of AAV.

Clinical significance of antineutrophil cytoplasmic antibody positivity in patients infected with SARS-CoV-2

Background. The Coronavirus Disease 2019 (COVID-19) is well-known for its broad spectrum of immune-related phenotypes similar to those seen in autoimmune or inflammatory diseases. Furthermore, evidence has gradually accumulated that COVID-19 may induce systemic inflammatory manifestations such as multisystem inflammatory syndrome, haemophagocytic syndromes, and systemic vasculitis. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a small vessel vasculitis characterised by necrotising vasculitis. So far, there have been several case reports regarding AAV occurrence after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which have indicated a triggering potential of SARS-CoV-2 infection for AAV occurrence. This study investigated the rate of ANCA positivity and its clinical significance in COVID-19 patients. Methods. This study included 178 patients infected with SARS-CoV-2 who were enrolled in a cohort of a single center. Myeloperoxidase (MPO)-ANCA and proteinase 3 (PR3)-ANCA from the stored blood sera were measured using the immunoassay kits. Mortality, mechanical ventilator care, and severe infection were assessed as poor outcomes. Severe infection was defined as a medical condition that required a high-flow nasal cannula and/or mechanical ventilator care. The 2022 American College of Rheumatology and the European Alliance of Associations for Rheumatology classification criteria for the three subtypes of AAV were applied only to patients who had MPO-ANCA or PR3-ANCA among the study subjects Results. The detection rate of ANCA positivity was 18.5%: MPO-ANCA and PR3-ANCA were found in 22 (12.4%) and 14 (7.9%) patients. Patients with ANCA positivity exhibited a lower cumulative survival rate than those without, but the difference was not statistically significant (P = 0.057). However, neither MPO-ANCA nor PR3-ANCA affected the three poor outcomes. According to the new criteria, 12 (6.7%) and 21 (11.8%) patients were classified as having granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) Neither ANCA positivity nor ANCA subtype (MPO-ANCA and PR3-ANCA) positivity had a significant influence on poor outcomes of SARS-CoV-2. ANCA: antineutrophil cytoplasmic antibody;MPO: myeloperoxidase;PR3: proteinase 3;SARS-CoV-2: severe acute respiratory syndrome coronavirus 2. Conclusion. SARS-CoV-2 infection may increase the rate of ANCA positivity, which may not affect poor outcomes but contribute to the classification of GPA and MPA despite uncertain clinical significance.

Evaluating ground glass opacities (GGO) in the COVID-19 era. Do autoantibodies help?

INTRODUCTION: COVID-19 is an infectious disease, caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and there have been outbreaks worldwide. The presentation may include unspecific and mild symptoms, myalgia, headaches, high fever, dry cough, severe dyspnea and acute respiratory distress syndrome (ARDS). CASE STUDY: We present a rare case of microscopic polyangiitis (MPA) with interstitial lung disease and without renal involvement misdiagnosed as COVID-19. CONCLUSIONS: Differential diagnosis of COVID-19 is extremely important, and must be correctly identified in order to proceed with correct treatment.

A CASE OF MICROSCOPIC POLYANGIITIS (MPA) FOLLOWING SARS-COV-2 INFECTION

SESSION TITLE: Unique Inflammatory and Autoimmune Complications of COVID-19 Infections SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/19/2022 12:45 pm - 1:45 pm INTRODUCTION: ANCA-associated vasculitis (AAV) is a systemic disease that causes inflammation of small vessels in various organs, such as the lungs, kidneys, and nervous system. We report a case of AAV following SARS-CoV-2 infection. CASE PRESENTATION: A 64-year-old female from Albania with no known medical history, presented with intermittent low-grade hemoptysis and fever for 1 week prior to admission. She had chills, myalgias, fatigue, and poor appetite 6 weeks prior. On arrival, she was febrile (101F), and hypoxic (Spo2 92% on 3L O2). Labs were significant for anemia [Hb 6.8 g/dl], acute kidney injury (AKI) [Cr 2.5 mg/dl]. She was found to be Positive for Sars-CoV-2 by PCR. Chest X-Ray showed patchy bilateral airspace opacities with peripheral and lower lobe predominance, concerning for atypical pneumonia (Fig 1). Urinalysis was significant for proteinuria (2+) and hematuria (2+). CT (Computed Tomography) thorax showed extensive bilateral airspace disease (dense consolidations and ground-glass opacities) favoring multifocal infection and mediastinal lymphadenopathy(Fig 2). Due to the chronicity of her symptoms and atypical imaging for viral pneumonia, other diagnoses were explored including bacterial superinfection, Tuberculosis, and autoimmune disease. Sputum studies were negative for infections including Acid Fast Bacilli. Workup revealed elevated Antimyeloperoxidase antibodies (MPO) and positive COVID-19 Ig G. She was started on methylprednisolone 1g for AAV. Renal biopsy revealed pauci-immune glomerulonephritis with features of cellular crescent consistent with microscopic polyangiitis (Fig 3). Follow-up CT chest showed improved airspace abnormalities and mediastinal lymphadenopathy. After induction therapy with Rituximab was initiated, she continued to recover and was discharged home. DISCUSSION: The pathogenesis of AAV is believed to be an aberrant pathogenic autoimmune response that follows an initial insult which can include infections. SARS-CoV-2 has been associated with the emergence of autoimmune diseases in susceptible patients(1). The proposed mechanism is linked to elevated levels of circulating neutrophil extracellular traps (NETs) observed in covid infection. These NETS are covered with proteins including neutrophilic enzymes which can activate complement pathways causing tissue destruction and vasculitis. The diagnosis of new-onset AAV can be challenging in COVID-19 patients as symptoms and clinical manifestations of both diseases can overlap. AAV should be considered strongly in patients who are currently infected or have been infected with SARS-CoV-2 and present with atypical or non-resolving pneumonia and other organ involvement such as AKI to avoid permanent organ damage. CONCLUSIONS: The presence of non-resolving or atypical pneumonia and AKI in a patient with SARS-CoV-2 should prompt evaluation of immunological markers to assess or rule out AAV for early diagnosis and treatment. Reference #1: Caso F, Costa L, Ruscitti P, Navarini L, Del Puente A, Giacomelli R, Scarpa R. Could Sars-coronavirus-2 trigger autoimmune and/or autoinflammatory mechanisms in genetically predisposed subjects? Autoimmun Rev. 2020;19(5):102524. doi: 10.1016/j.autrev.2020.102524 DISCLOSURES: No relevant relationships by Tarik Al-Bermani No relevant relationships by Anant Jain No relevant relationships by Ian Kaplan No relevant relationships by Alina Kifayat No relevant relationships by Lisa Paul

Autoimmune Vasculitis Causing Acute Bilateral Lower Limb Paralysis.

Autoimmune vasculitis is an autoimmune disease that causes various systemic symptoms, such as fever, fatigue, joint pain, and night sweats. Its clinical course depends on the severity of the inflammation, which can cause acute clinical progression of symptoms. Moreover, when the inflammation of the arteries occurs in the deeper parts of the body, a biopsy may be difficult to perform. Here, we report a case of autoimmune vasculitis in an elderly man who visited our hospital with a chief complaint of muscle pain and fever triggered by a rapid paralysis of both lower limbs. Autoimmune vasculitis can cause a variety of systemic symptoms depending on the size of involved arteries, and its clinical course depends on the severity of the inflammation. Prompt diagnosis and simultaneous treatment of symptoms, excluding other likely diseases, prevent the development of severe and long-term complications of autoimmune vasculitis.

LATE-ONSET NEUTROPENIA after RITUXIMAB TREATMENT in PATIENTS with ANCA-ASSOCIATED SYSTEMIC VASCULITIS: A RETROSPECTIVE ANALYSIS of A REGISTER-BASED PATIENT COHORT

Background: Anti-B-cell therapy with rituximab (RTX) plays an important role in the induction and maintenance therapy of ANCA-associated vasculitis (AAV). Late-onset neutropenia (LON) has been reported following RTX therapy. Objectives: Based on a retrospective analysis of the register of AAV patients (pts) treated with RTX, to study the incidence and outcomes of LON. Methods: 140 AAV pts (median age 52 (20-83) years, 57% women) were treated with RTX between 2009 to 2021: 63 with granulomatosis with polyangiitis (GPA), 45 microscopic polyangiitis (MPA), 24 eosinophilic granulomatosis with polyangi-itis (EGPA), and 8 unclassifed AAV. The median total dose of RTX was 3.5 (0.5-45) g. As a rule, single 500-mg infusions were used with an interval of 4-6 months for retreatment courses. The duration of follow-up exceeded 6 months after the frst dose of RTX. Regular pts monitoring every 3 months included estimation absolute neutrophil count (ANC). LON was defned as unexplained neutropenia occurring 3 weeks after the last RTX infusion. Results: LON I-IV grade was noted in 16 (11.4%) AAV pts: 6 GPA, 4 MPA, EGPA, and 2 unclassifed AAV. In 7 out of 16 cases (43.7%) LON developed after the frst course of RTX. Neutropenia grade I was observed in 3 pts (ANC 1.68-2.0x109/l, 2-15.5 months after the last RTX infusion), grade II-in 4 patients (1.1-1.5x109/l, 3-9 months after RTX). Neutropenia grade I-II resolved independently, without adverse reactions. LON grade IV was noted in 9 pts (0.06-0.3x109/l, 1.1-11 months after RTX), 3 of them received leukopoie-sis-stimulating drugs with normalization of ANC. In one EGPA pt febrile LON grade IV developed twice (in 2017, 11 months after RTX;in 2019, 4 months after RTX and complicated by uterine bleeding). Fatal outcome occurred in out of 16 cases (31.2%): 1 MPA, 3 GPA, and 1 EGPA. In 3 fatal cases LON was complicated by pneumonia (in 2 with septic shock), in one with acute myocardial infarction and another one with progression of chronic renal failure. According to our registry, the total mortality among 140 AAV pts receiving RTX was 11.4%, while 5 of 16 fatal cases (31.2%) had LON grade IV. Three of the 5 death were noted in 2013-2014, which attributed to the use of cyclophos-phamide >2 gm before RTX, as well as insufficient awareness of the risk of LON, which contributed to the delay in control of a full blood count, untimely diagnosis of LON and late treatment. At the beginning, the original drug Mab-thera was used, while after 2014 biosimilar Acellbia was mainly used. The disadvantages of this study: the lack of information about the ANC in 4 cases with COVID-19 and fatal outcome. Conclusion: LON after RTX therapy can develop in 11.4% of AAV pts, which exceeds the data for rheumatoid arthritis (1,3-3%) [1,2]. Our register data are lower than the rate of LON in AAV, presented by D. Tesfa et al. (23%) [1], which could be affected by the use of low-dose RTX for retreatment courses. LON accounts for a signifcant part in the structure of deaths of AAV pts (31.2%). It needs to careful monitoring of ANC in pts receiving RTX and awareness of both pts and physicians about the risk of LON.

Isolated arteritis misdiagnosed as bilateral orbital tumors in a patient with acute ischemic stroke.

Vasculitis is a heterogeneous group of disorders characterized by multifocal segmental inflammation of the small and medium vessels of the central nervous system. The predominant symptoms of cerebral vasculitis are stroke, headache, and encephalopathy. Additional symptoms include seizures, cranial nerve palsies, and myelopathy. Imaging techniques play a crucial role in identifying the diagnosis of vasculitis and demonstrating brain involvement. An 89-year-old woman with permanent atrial fibrillation developed an embolic stroke. In treatment, intravenous thrombolysis and thrombectomy with complete antegrade reperfusion of the left middle cerebral artery was used, without the clinical effectiveness. Brain MRI revealed bilateral oval lesions in medial parts of the orbits, which were initially misinterpreted as orbital tumors. Final diagnosis confirmed thickened arterial walls as orbital changes due to inflammatory arteritis. Ten days later, follow-up MRI was performed and showed complete regression of the orbital masses. Primary central nervous system vasculitis, manifesting as acute ischemic stroke, may be reversible with early systemic thrombolytic treatment.

Respiratory tract involvement in the different ANCA-associated vasculitides - a comparative analysis in a cohort of Bulgarian patients

ANCA-associated vasculitides (AAV) are multisystem autoimmune diseases characterised by necrotizing inflammation of small blood vessels, production of antibodies against antigens found in the cytoplasm of neutrophils (ANCA) and various organ manifestations. The aim of the present study was to analyse the type and frequency of symptoms of respiratory tract involvement in AAV. A total of 145 patients with AAV were included in the study, of which 80 had granulomatosis with polyangiitis (GPA), 52 with microscopic polyangiitis (MPA), 8 with Churg-Strauss syndrome (CSS) and 5 with undifferentiated vasculitis. Of all patients with AAV, respiratory tract involvement was observed in 118. Symptoms of involvement of the upper airways were significantly more common in GPA compared to MPA and CSS (p = 0.0000). The most common manifestation was rhinorrhoea, which had blood stains in 78.6% of patients. Involvement of the paranasal sinuses was reported in 47 patients, mainly those with GPA (71.4%). A total of 110 patients, or 75.9%, had symptoms of pulmonary involvement, which makes the lung the most commonly targeted organ in Bulgarian patients with AAV. Pulmonary manifestations were most common in patients with GPA (65.6%), followed by MPA (24.5%) and CSS (7.3%);all differences were reported to be statistically significant (p = 0.0000). The most frequently observed symptom in our patients was cough - in 83 individuals, and in 57 patients (68.57%) it was accompanied by blood-stained sputum. Alveolar haemorrhage was observed significantly more often in cases of MPA (p = 0.0266), the same being true of respiratory failure (p = 0.0257). The conducted computed tomography (CT) scans showed predominantly nodules (in 54.5% of cases with pulmonary involvement), and 19.1% of them evolved to cavitations. Nodules were a significantly more common finding in patients with GPA - in 68.1% of cases (p = 0.0000). The typical findings of vasculitis - alveolar damage and 'ground glass' opacities were found significantly more often in MPA (p = 0.0150). Pulmonary fibrosis was observed in both GPA and MPA.

Microscopic Polyangiitis Following mRNA COVID-19 Vaccination: A Case Report.

Coronavirus disease 2019 (COVID-19) is one of the most widespread viral infections in human history. As a breakthrough against infection, vaccines have been developed to achieve herd immunity. Here, we report the first case of microscopic polyangiitis (MPA) following BNT162b2 vaccination in Korea. A 42-year-old man presented to the emergency room with general weakness, dyspnea, and edema after the second BNT162b2 vaccination. He had no medical history other than being treated for tuberculosis last year. Although his renal function was normal at last year, acute kidney injury was confirmed at the time of admission to the emergency room. His serum creatinine was 3.05 mg/dL. Routine urinalysis revealed proteinuria (3+) and hematuria. When additional tests were performed for suspected glomerulonephritis, the elevation of myeloperoxidase (MPO) antibody (38.6 IU/mL) was confirmed. Renal biopsy confirmed pauci-immune anti-neutrophil cytoplasmic antibody (ANCA)-related glomerulonephritis and MPA was diagnosed finally. As an induction therapy, a combination of glucocorticoid and rituximab was administered, and plasmapheresis was performed twice. He was discharged after the induction therapy and admitted to the outpatient clinic 34 days after induction therapy. During outpatient examination, his renal function had improved with serum creatinine 1.51 mg/dL. We suggest that MPA needs to be considered if patients have acute kidney injury, proteinuria, and hematuria after vaccination.

A Rare Case of Concurrent New-Onset Microscopic Polyangiitis and Thrombotic Thrombocytopenic Purpura in a 77-Year-Old Woman

Introduction: Microscopic polyangiits (MPA) is a rare ANCA-associated necrotizing vasculitis that affects the small vessels, often involving the lung or kidney. When presenting with diffuse alveolar hemorrhage, this disease warrants emergent treatment, often with plasma exchange. Here, we present a rare case of a patient presenting with alveolar hemorrhage in the setting of MPA and concurrent thrombotic thrombocytopenic purpura (TTP) with an extremely reduced ADAMTS13 activity. Case Report: A 77 y/o woman with HTN and PUD presented to outside facility with new onset anemia (Hb 6.3 g/dL). Positive Coombs test gave her a tentative diagnosis of hemolytic anemia, and she was transfused 2 U RBCs. Ten days later, she presented to our hospital with respiratory distress. Hb remained stable at 10.7 but had leukocytosis with WBC 22,000 with left shift, platelets 439. Vitals not consistent with sepsis though saturating 70-80% on room air. In the ED, she developed frank hemoptysis and was emergently intubated. CTA chest was negative for pulmonary embolus but demonstrated diffuse ground-glass opacities. COVID test negative. Bronchoscopy was consistent with diffuse alveolar hemorrhage (DAH), and she received tranexamic acid, crystalloids, 1 U RBCs. Suspicious for underlying vasculitic process, she was given pulse dose IV steroids (1 g methylprednisolone daily) and started plasma exchange. Creatinine on presentation was elevated at 1.77 but she continued to have adequate urine output and appropriate volume status. Her hospital course was marked by progressive thrombocytopenia with schistocytes appreciated on peripheral smear. ADAMTS13 activity <5% with inhibitor detected, consistent with TTP. Vasculitic workup revealed positive myeloperoxidase antibodies and p-ANCA consistent with MPA. Other rheumatologic workup ANA positive 1:640 and positive IgM cardiolipin antibodies;she had no personal autoimmune history but some family autoimmune disease including one daughter with systemic lupus erythematosus and another relative with Guillian-Barre. She remained intubated for 4 days and post-extubation experienced some short-lived ICU delirium but after made a remarkable recovery. She completed 12 total sessions of of plasma exchange and 3 of 4 planned doses of rituximab, to continue on oral steroids outpatient and prophylactic TMP-SMX. She was discharged to rehab facility on hospital day 20. Discussion: With diffuse alveolar hemorrhage on presentation, initial differential remained broad including delayed presentation of transfusion-related lung injury (TRALI) given recent history of transfusion. She had recently started hydralazine outpatient. Along with positive ANA, this could suggest drug-induced lupus. However, histone antibodies were negative, but results may have been compromised by steroids and plasma exchange. Both MPA and TTP can be deadly but are managed with similar treatment. Luckily, our patient was rapidly initiated on plasma exchange following hospitalization. Although further workup including ADAMTS13 and vasculitis labs were pending at the time, it is important to not delay treatment while awaiting results. Cased of concurrent TTP and ANCA-associated vasculitis have been described in the literature, but the full relationship between these two entities remains unclear. TTP may develop after starting glucocorticoids in the setting of ANCA vasculitis, so close monitoring is recommended. Disclosures: No relevant conflicts of interest to declare.

A Rare Case of SARS-CoV-2-Induced Microscopic Polyangiitis.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection triggers elevated levels of circulating cytokines and immune-cell hyperactivation, called a cytokine storm, which leads to dysregulated immune response not only towards the pathogen itself but also contributes to cellular, vascular injury and multiorgan dysfunction. The cytokine-induced endothelial inflammation and vascular pathology of COVID-19 is well reported in post-mortem biopsies and several cases reporting small, medium and large vessel micro/macro thrombotic events and vasculitis in multiple organs. So far, few cases have been reported with newly diagnosed antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis at the time of acute COVID-19 infection. The exact pathophysiology of SARS-CoV-2 and ANCA-associated vasculitis continues to be studied and reviewed. Here we report a case of a 60-year-old female who presented to our institution with sudden onset of shortness of breath and hemoptysis. A detailed history revealed a recent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Labs showed elevated serum creatinine, urine analysis with large blood and nephrotic range proteinuria. CT chest was remarkable for abnormal appearance of the parenchyma bilaterally compatible with a crazy paving pattern, suggesting pulmonary alveolar proteinosis versus diffuse alveolar hemorrhage. Vasculitis was suspected and the patient was started on IV corticosteroids and plasmapheresis. Diagnostic workup was positive for antineutrophil cytoplasmic antibodies-myeloperoxidase (ANCA-MPO), anti-Sjögren's syndrome-related antigen A autoantibodies (anti-SS-A) and antinuclear antibodies (ANA). Renal biopsy confirmed focal segmental necrotizing, crescentic and sclerosing glomerulonephritis, pauci-immune type, anti-MPO antibody/P-ANCA associated. A diagnosis of microscopic polyangiitis was made and she was started on rituximab immunosuppressive therapy following which she showed clinical improvement. In this document, we present a unique case of microscopic polyangiitis possibly induced by SARS-CoV-2 infection confirmed by renal biopsy and clinical presentation. In the current setting of a global pandemic, we strongly recommend that vasculitis be high on the differential diagnosis in patients who are currently infected or had been infected with SARS-CoV-2 and present with acute kidney injury (AKI).

Life-Threatening Diffuse Alveolar Hemorrhage as an Initial Presentation of Microscopic Polyangiitis: COVID-19 as a Likely Culprit.

Microscopic polyangiitis (MPA) is a systemic small vessel vasculitis but it is rare to see life-threatening diffuse alveolar hemorrhage (DAH) in MPA as an initial presentation. MPA more commonly presents with renal involvement and develops pulmonary manifestations later in the disease course. Our patient is a 77-year-old female with a recent history of recovered COVID-19 infection who presented with sudden onset fever, dyspnea, and hemoptysis for three days. She was diagnosed with MPA because of the new-onset DAH, a strongly positive myeloperoxidase (MPO) antibody, and the low likelihood of another etiology. The patient was treated with pulse-dose steroids and plasmapheresis while being on mechanical ventilation. This case highlights the importance of the prompt recognition of DAH as an initial presentation of MPA and illustrates the possible role of COVID-19 in inciting autoimmune conditions.