Antineutrophil Cytoplasmic Autoantibodies Research Articles

Laboratory diagnostics for vasculitis beyond antineutrophil cytoplasmatic autoantibodies

The diagnosis of systemic vasculitis (SV) is amajor clinical challenge due to the very different forms of presentation and requires an interdisciplinary approach. Targeted laboratory diagnostics support making the diagnosis, differential diagnosis and classification and are also akey component in the detection of active organ manifestations and treatment complications. The basic laboratory tests include the erythrocyte sedimentation rate (ESR), C‑reactive protein (CRP), blood count, serum creatinine, urinalysis, specific autoantibodies, complement, immunoglobulins, cryoglobulins and hepatitisB and C serology. Antineutrophil cytoplasmic autoantibodies (ANCA), antiglomerular basement membrane antibodies (anti-GBM antibodies) and anti-C1q antibodies are valuable laboratory markers for the diagnosis of the various forms of small vessel vasculitis. There are no specific laboratory tests for the diagnosis of medium and large vessel vasculitis. Despite advances in our understanding of the pathogenesis of vasculitis, no biomarkers have yet been identified that can be reliably used to guide treatment or that are useful in distinguishing vasculitis from other inflammatory diseases such as infections or treatment complications.

The Diagnosis of Granulomatosis With Polyangiitis When Serology and Biopsies are Negative.

Granulomatosis with polyangiitis (GPA) is a potentially fatal condition which often manifests in the head and neck. Currently, diagnosis relies on antineutrophil cytoplasmic autoantibody (c-ANCA) serology and mucosal or renal biopsy. However, a significant proportion of patients with GPA limited to the head and neck are seronegative and biopsy negative. This study evaluates the role of clinical diagnosis of GPA in the absence of positive laboratory findings. Case series with chart review. Academic Tertiary Medical Center. This was a retrospective review of 143 patients treated in an outpatient otolaryngology clinic at a tertiary care hospital for known or suspected GPA from 1998 to 2021. Presenting symptoms, C-ANCA status at initial presentation, biopsy results, long-term serology results, and time to initiation of treatment were analyzed. Twenty-six of 143 (18.2%) patients were seronegative; only 3 of these patients (12%) had positive biopsies. Seventeen (73.9%) of these patients presented with nasal and sinus disease and 12 (52.2%) presented with airway involvement. Only 4 (17.4%) patients had renal involvement. Delay in treatment of patients with negative laboratory workup ranged from 0 months to 11 years. All patients who were seronegative and/or biopsy negative at presentation responded clinically to immunosuppressive therapy. GPA cases are often limited to the upper respiratory tract, making diagnosis difficult, particularly in seronegative patients. These results suggest that, when GPA is suspected, despite negative serology, the diagnosis of GPA should be made on clinical grounds, and empiric therapy encouraged to prevent delay in treatment.

High-resolution epitope mapping of commercial antibodies to ANCA antigens by yeast surface display

Epitope mapping provides critical insight into antibody-antigen interactions. Epitope mapping of autoantibodies from patients with autoimmune diseases can help elucidate disease immunogenesis and guide the development of antigen-specific therapies. Similarly, epitope mapping of commercial antibodies targeting known autoantigens enables the use of those antibodies to test specific hypotheses. Anti-Neutrophil Cytoplasmic Autoantibody (ANCA) vasculitis results from the formation of autoantibodies to multiple autoantigens, including myeloperoxidase (MPO), proteinase-3 (PR3), plasminogen (PLG), and peroxidasin (PXDN). To perform high-resolution epitope mapping of commercial antibodies to these autoantigens, we developed a novel yeast surface display library based on a series of >5000 overlapping peptides derived from their protein sequences. Using both FACS and magnetic bead isolation of reactive yeast, we screened 19 commercially available antibodies to the ANCA autoantigens. This approach to epitope mapping resulted in highly specific, fine epitope mapping, down to single amino acid resolution in many cases. Our study also identified cross-reactivity between some commercial antibodies to MPO and PXDN, which suggests that patients with apparent autoantibodies to both proteins may be the result of cross-reactivity. Together, our data validate yeast surface display using maximally overlapping peptides as an excellent approach to linear epitope mapping.

Pharmacokinetic Evaluation of the CYP3A4 and CYP2C9 Drug-Drug Interaction of Avacopan in 2 Open-Label Studies in Healthy Participants.

Avacopan, a complement 5a receptor (C5aR) antagonist approved for treating severe active antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, was evaluated in 2 clinical drug-drug interaction studies. The studies assessed the impact of avacopan on the pharmacokinetics (PK) of CYP3A4 substrates midazolam and simvastatin and CYP2C9 substrate celecoxib, and the influence of CYP3A4 inhibitor itraconazole and inducer rifampin on the PKs of avacopan. The results indicated that twice-daily oral administration of 30mg of avacopan increased the area under the curve (AUC) of midazolam by 1.81-fold and celecoxib by 1.15-fold when administered without food, and twice-daily oral administration of 30 or 60mg of avacopan increased the AUC of simvastatin by approximately 2.6-3.5-fold and the AUC of the active metabolite β-hydroxy-simvastatin acid by approximately 1.4-1.7-fold when co-administered with food. Furthermore, the AUC of avacopan increased by approximately 2.19-fold when co-administered with itraconazole and decreased by approximately 13.5-fold when co-administered with rifampin. These findings provide critical insights into the potential drug-drug interactions involving avacopan, which could have significant implications for patient care and treatment planning. (NCT06207682).

Granulomatosis with polyangiitis and microscopic polyangiitis

Granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) are two entities of ANCA-associated vasculitis (AAV). Both diseases are characterised by systemic necrotising small-vessel vasculitis, which can affect any organ. In GPA, extravascular necrotising granulomatous inflammation, usually affecting the respiratory tract, is found in addition. In the majority of cases, the clinical presentation is dominated by a pulmonary-renal syndrome with alveolar haemorrhage and rapidly progressive glomerulonephritis. Other organ involvement is found as well. In GPA, the upper respiratory tract is commonly affected. GPA is associated with anti-neutrophil cytoplasmic autoantibodies (ANCA) with specificity for proteinase 3 (PR3-ANCA) and MPA with specificity for myeloperoxidase (MPO-ANCA). Immunosuppressive therapy depends on disease activity and the severity of organ involvement.

Development of a Kidney Prognostic Score in a Japanese Cohort of Patients With Antineutrophil Cytoplasmic Autoantibody Vasculitis

Glomerulonephritis is frequent in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and crucial to disease outcomes. We conducted a detailed assessment of renal pathology in Japanese patients with AAV, and developed a new score that would predict renal outcome. Two hundred twenty-one patients who were diagnosed with AAV and underwent a kidney biopsy were enrolled. Data on glomerular, tubular, interstitial, and vascular lesions from kidney biopsies were analyzed; the 3 established classification and prognostic scoring systems (Berden Classification, Mayo Clinic/RPS Chronicity Score [MCCS], and ANCA Renal Risk Score [ARRS]) were validated. Further, we developed a new prognostic score by including variables relevant for Japanese patients with ANCA-glomerulonephritis. Median follow-up was 60 months (interquartile range: 6-60). End-stage kidney disease (ESKD) risk prediction by the MCCS and the ARRS was confirmed. Moreover, our analysis identified 4 items with significant ESKD risk prediction capacity, namely percentage of cellular, fibrocellular, and fibrous crescents; and sclerotic glomeruli. Based on our findings, we created a score evaluating the percentage of these lesions to total glomeruli, the Percentage of ANCA Crescentic Score (PACS). The area under the receiver operating characteristic (ROC) curve evaluating PACS was 0.783. The PACS had a comparable performance as the ARRS in predicting ESKD. The optimal PACS cut-off for ESKD risk over 60 months was 43%. In addition, the percentage of cellular crescents and presence of interstitial inflammation were independent predictors of kidney function recovery. We developed a new score predicting renal prognosis using histopathological data of Japanese patients with ANCA-glomerulonephritis. Studies are needed to validate our results in international cohorts.

Antineutrophil Cytoplasmic Autoantibody-negative Pauci-immune Necrotizing Glomerulonephritis with Plasma Cell-rich Tubulointerstitial Nephritis Complicated with Pleuritis and Digital Ischemia.

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) predominantly affects small vessels. Almost all AAV patients are positive for myeloperoxidase- or proteinase 3-ANCA, and ANCA plays a crucial role in the pathogenesis of AAV. We herein report an ANCA-negative AAV patient with pauci-immune necrotizing glomerulonephritis and plasma cell-rich tubulointerstitial nephritis who was complicated with pleuritis and digital ischemia. ANCA-negative AAV is a rare clinical entity that is difficult to diagnose, and pleuritis and digital ischemia are rare manifestations of AAV. An early diagnosis and appropriate treatment are important, as any delay in the diagnosis may worsen the prognosis.

Cardiac valvular involvement in granulomatosis with polyangiitis in long-term observation

Introduction and objectivesGranulomatosis with polyangiitis (GPA) is an antineutrophil cytoplasmic autoantibody (ANCA)-associated systemic vasculitis and is characterized by inflammation of blood vessels. The aim of the present study was to assess cardiac valvular changes in patients with GPA in a cohort of 105 patients followed for a mean of six years. MethodsWe followed 105 patients (mean age 50.4 years, 67 female) for a mean of 6.2±1.3 years. Echocardiography and laboratory tests were performed in all patients. ResultsAt baseline, 43% of patients were diagnosed with aortic regurgitation (AR), which was the most common valvular lesion. Moreover, it was the only valvular involvement that significantly increased during observation (p=0.01). In a multivariate model, only D-dimer level was a predictor of AR in this group of patients (OR 8.0 (95% CI: 1.7–38.2, p=0.01). ConclusionsInvolvement of the heart valves is a common finding in patients with GPA, but significant valvular disease is a rare complication. The most common valvular disease in this group of patients is AR. Aortic valves are also the most prone to degeneration in the course of the vasculitis.

Efficacy and safety of avacopan in patients with ANCA-associated vasculitis receiving rituximab in a randomised trial

ObjectivesTo evaluate the efficacy and safety of avacopan in the subgroup of patients with antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis receiving background induction therapy with rituximab in the phase 3 ADVOCATE...

A microRNA sponge, LINC02193, promotes neutrophil activation by upregulating ICAM1 and is correlated with ANCA-associated vasculitis

Abstract Objective To investigate the pathogenic role and underlying mechanisms of long noncoding RNAs (lncRNAs) in ANCA-associated vasculitis (AAV). Methods RNA-sequencing (RNA-seq) was applied to screen the expression profile of lncRNAs in peripheral leukocytes from five AAV patients and five healthy controls (HC). Candidate lncRNAs were preliminarily verified in peripheral leukocytes from 46 AAV patients and 35 HC by qRT-PCR. Then, the identified LINC02193 was further validated in peripheral neutrophils from 67 AAV patients, 45 HC and 64 disease controls. Correlation between LINC02193 levels and disease activity was analysed. Then, a loss-of-function study was conducted to investigate the role of LINC02193 in neutrophils activation. Furthermore, bioinformatics analysis, dual luciferase reporter and RNA immunoprecipitation assays were performed to explore the mechanism of LINC02193 regulating neutrophils activation. Results A total of 467 upregulated and 412 downregulated lncRNAs were identified in AAV patients. From the top five upregulated lncRNAs, an elevation of LINC02193 was validated in a larger sample of AAV patients, and positively correlated with disease activity. Knockdown of LINC02193 inhibited reactive oxygen species and nitric oxide production, neutrophil extracellular traps release and adhesion to endothelial cells of differentiated human promyelocytic leukaemia HL-60 cells, whereas overexpression of ICAM1 counteracted these effects. Mechanistic analysis demonstrated that LINC02193 acted as an miR-485-5p sponge to relieve the repressive effect of miR-485-5p on ICAM1, thus promoting ICAM1 expression. Conclusion LINC02193, a novel lncRNA identified in AAV, could function as competing endogenous RNAs for miR-485-5p to promote ICAM1 expression and neutrophils activation, suggesting its potential as a therapeutic target of AAV.

Prediction-Related Hint, Result and Effect of Anti-Neutrophil Cytoplasmic Autoantibodies with Myeloperoxidase Level of Detail in Anti-Glomerular Basement Membrane Disease

Now not made with the aid of nature/fake intelligence is gambling a increasingly more crucial role in lots of fields of medication, helping doctors in most steps of patient management. In nephrology, (no longer made with the aid of nature/faux) intelligence can already be used to enhance medication-primarily based care, hemodialysis prescriptions, and comply with-up of transplant receivers. but many nephrologists are nevertheless unfamiliar with the basic regulations/approaches of taking into account scientific (no longer made via nature/faux) intelligence. This evaluation attempts to provide a precis of clinical.

Avacopan (Tavneos)


 CADTH reimbursement reviews are comprehensive assessments of the clinical effectiveness and cost-effectiveness, as well as patient and clinician perspectives, of a drug or drug class.
 The assessments inform non-binding recommendations that help guide the reimbursement decisions of Canada's federal, provincial, and territorial governments, with the exception of Quebec.
 This review assesses avacopan (Tavneos), 30 mg (3 oral capsules of 10 mg each), twice daily.
 Indication: For the adjunctive treatment of adult patients with severe antineutrophil cytoplasmic autoantibody–associated vasculitis (granulomatosis with polyangiitis and microscopic polyangiitis) in combination with standard background therapy including glucocorticoids. Avacopan does not eliminate glucocorticoid use.

Pauci-immune crescentic glomerulonephritis caused to dilemma in a patient with suspected systemic lupus erythematosus: a case report.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease and there is a distinct differentiation of clinical manifestations. Lupus nephritis (LN) is clinically apparent in approximately half of patients. A kidney biopsy is essential to define the kidney injury, exclude other injurious causes, and determine the histopathologic subtypes. Autoantibodies are crucial to the pathogenesis and the deposition of immune complexes in glomeruli is a hallmark of LN. The histopathology of LN is quite varied. Despite pauci-immune LN being an unexpected condition in SLE, it has been observed rarely with the presence of antineutrophil cytoplasmic autoantibodies (ANCA). We present a young male who was admitted to the emergency with syncope. The brain imaging revealed small infarct areas and signs of cerebral vasculitis. Also, he had elevated inflammatory markers, moderate proteinuria, and preserved kidney function. Anti-nuclear antibodies and anti-dsDNA were positive. Pauci-immune crescentic glomerulonephritis (PICGN) was observed in a kidney biopsy, however, ANCA was negative. SLE diagnosis was established by neurological manifestation, specific antibodies, proteinuria, and kidney biopsy findings. We administered a combination induction regimen, including pulse steroid and parenteral cyclophosphamide. The proteinuria was resolved in the follow-up. Our case highlights that SLE-associated ANCA-negative PICGN can be the initial presentation in the absence of typical manifestations. LN exhibits various pathological mechanisms in the kidney. As a consequence, SLE should be considered in the differential diagnosis of all forms of kidney injury.

Clinicopathological Features and Outcomes of IgA Nephropathy with Serum Antineutrophil Cytoplasmic Autoantibody Positivity

Introduction: IgA nephropathy (IgAN) with serum antineutrophil cytoplasmic autoantibody (ANCA) positivity is uncommon. This study analyzed the clinicopathologic features and prognosis of IgAN patients with serum ANCA positivity. Methods: 2,864 IgAN patients were tested for ANCA by the indirect immunofluorescence assay and chemiluminescence immunoassay. Patients with serum ANCA positivity (n = 85) were identified, and their clinical, pathological, and prognostic characteristics were analyzed. They were compared with ANCA-negative IgAN patients (n = 170) and ANCA-associated systemic vasculitis (AAV) with renal involvement patients (n = 85) selected randomly. Results: 2.97% (85/2,864) of IgAN were ANCA positive, and 4 patients were diagnosed as having crescentic IgAN with ANCA positivity. The clinicopathological characteristics of ANCA-positive IgAN patients were comparable to ANCA-negative IgAN patients, but they had higher antinuclear antibody (ANA)-positive rates, lower levels of renal interstitial inflammation, and fewer immune depositions than ANCA-negative IgAN patients. Compared with AAV patients, ANCA-positive IgAN patients were younger and had fewer extrarenal manifestations, milder renal damage, and more immune complex depositions. The renal outcomes were similar between IgAN patients with and without ANCA positivity. Multivariate Cox analysis revealed that in IgAN patients with ANCA positivity, male, ANA positivity, higher serum creatinine and proteinuria, and more severe renal tubular atrophy/interstitial fibrosis were risk factors for adverse renal outcomes. Conclusion: The clinical, pathological features and prognosis of ANCA-positive IgAN patients were similar to those of ANCA-negative IgAN patients except for higher ANA-positive rate, milder renal inflammation, and fewer immune depositions. ANA positivity was an independent risk factor for adverse renal outcomes in ANCA-positive IgAN patients.

The involvement of NETs in ANCA-associated vasculitis.

Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is a serious autoimmune disease that is characterized by vascular necrosis. The pathogenesis of AAV includes ANCA-mediated neutrophil activation, subsequent release of inflammatory cytokines and reactive oxygen species (ROS), and formation of neutrophil extracellular traps (NETs). Excessive NETs could participate not only in ANCA-mediated vascular injury but also in the production of ANCAs per se as autoantigens. Thus, a vicious cycle of NET formation and ANCA production is critical for AAV pathogenesis. Elucidating the molecular signaling pathways in aberrant neutrophil activation and NETs clearance systems will allow specific therapeutics to regulate these pathways. Currently, standard therapy with high doses of glucocorticoids and immunosuppressants has improved outcomes in patients with AAV. However, AAV frequently develops in elderly people, and adverse effects such as severe infections in the standard regimens might contribute to the mortality. Mechanistically, cytokines or complement factors activate and prime neutrophils for ANCA-binding; thus, C5a receptor blocker has garnered attention as potential replacement for glucocorticoids in clinical settings. Recent studies have demonstrated that receptor-interacting protein kinases (RIPK3) and cyclophilin D (CypD), which regulate cell necrosis, may be involved in ANCA-induced NETs formation. Meanwhile, targeting NETs clearance, including the addition of deoxyribonuclease I (DNase I) and macrophage engulfment, may improve vasculitis. In this review, we focus on the pathogenesis of NETs and discuss potential targeted therapies for AAV based on recent experimental evidence.

Impact of Diabetic Lesions on Pathology, Treatment and Outcomes of Glomerular Diseases.

We aimed to evaluate whether concomitant diabetic glomerulosclerosis (DGS) and its severity impact the treatment and outcomes of primary glomerular diseases (GD) with comorbid diabetes. We conducted a retrospective review of people with diabetes and GD. We searched the Glomerular Disease Collaborative Network for biopsies from 2008 to 2015 among persons with diabetes and any of the following diagnoses: Focal Segmental Glomerulosclerosis (FSGS), IgA Nephropathy (IgAN), Minimal Change Disease (MCD), Membranous Nephropathy (MN) or Anti-Neutrophil Cytoplasmic Autoantibody Glomerulonephritis (ANCA GN). Data were abstracted from health records and histologic diabetic glomerular class scored. The primary composite endpoint was end-stage kidney disease (ESKD) or death. Multivariable Cox regression models tested whether any or the severity of diabetes histopathology impacted the primary endpoint. Data from 134 cases were available for analysis (78 DGS+GD and 56 GD alone). Diabetes duration and glycemic control were similar between the two groups (p=0.2; p=0.09, respectively). Use of immunosuppression did not differ between the two groups (p=0.3). The composite endpoint was significantly higher in DGS+GD [22.5 cases per 100 p-y (95% CI: 16.6-30.5)] versus GD alone [10.2 cases per 100 p-y (95% CI: 6.4-16.2)]. Regression analyses demonstrated that compared to the GD alone group, the risk for the composite endpoint was similar in the group with mild DGS+GD (DGS class 1, 2a) [HR=1.15 (95% C: 0.54-2.43)], while the group with severe DGS+GD (DGS class 2b, 3, 4) had a greater risk [HR=3.60 (1.79-7.22)]. Among people with diabetes and GD, mild diabetic glomerular lesions on biopsy do not impact outcomes, but moderate-severe lesions increase the risk for ESKD and death. Whether use of immunosuppression, particularly glucocorticoids, is less successful in inducing GD remission in people with moderate-severe diabetic lesions will be a focus of future study in a larger population.

Animal models for anti-neutrophil cytoplasmic antibody-associated vasculitis: Are current models good enough?

Antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) is a rare and severe systemic autoimmune disease characterized by pauci-immune necrotizing inflammation of small blood vessels. AAV involves multiple organ systems throughout the body. Our knowledge of the pathogenesis of AAV has increased considerably in recent years, involving cellular, molecular and genetic factors. Because of the controlled environment with no other confounding factors, animal models are beneficial for studying the mechanistic details of disease development and for providing novel therapeutic targets with fewer toxic side effects. However, the complexity and heterogeneity of AAV make it very difficult to establish a single animal model that can fully represent the entire clinical spectrum found in patients. The aim of this review is to overview the current status of animal models for AAV, outline the pros and cons of methods, and propose potential directions for future research.

Urine and Plasma Complement Ba Levels During Disease Flares in Patients With Antineutrophil Cytoplasmic Autoantibody–Associated Vasculitis

Although the alternative complement pathway has been implicated in the pathogenesis of antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV), the specific nature of its involvement is unclear. This study measured levels of urine and plasma complement fragment Ba at multiple time points in a group of patients with AAV. The complement fragment Ba was measured by enzyme-linked immunosorbent assay in serial urine and plasma samples from 21 patients with AAV who developed a renal flare, 19 who developed a nonrenal flare, and 20 in long-term remission. Urine Ba levels were corrected for urine creatinine concentration. Changes in Ba levels were modeled using mixed linear-effect models. A logistic regression model was fit to predict a renal flare using Ba levels at the time of flare versus the nonrenal flare and long-term remission groups. Data from 60 patients with AAV were used for this analysis; 53% were male, 93% were White, and 74% had antiproteinase3-ANCA. Urine Ba levels increased at renal flare (P< 0.001) but remained stable during a nonrenal flare or long-term remission. Plasma Ba levels were stable over time in all groups. Urine Ba levels predicted a renal flare with an area under the curve of 0.76 (P< 0.001), with a cutoff of 12.53 ng/mg urine creatinine yielding a sensitivity of 76.2% and a specificity of 68.4%. Urine Ba levels, but not plasma Ba levels, are increased at the time of a renal flare in AAV, suggesting intrarenal complement activation and highlighting the potential use of this biomarker for surveillance of active renal vasculitis.

SARS-CoV-2 infection and increasing autoimmune disorders among ICU-hospitalized COVID-19 patients.

In acute conditions, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes multi-organ damage due to the induction of inappropriate immune responses, particularly lung tissue fibrosis. To evaluate the consequence of the deterioration of the immune system, autoimmune markers were assessed. In a case-control study, 108 patients with coronavirus disease 2019 (COVID-19) were admitted to the intensive care unit (ICU), and 158 outpatients with mild clinical symptoms, with SARS-CoV-2 reverse transcription quantitative polymerase chain reaction (RT-qPCR) positive tests, were included for comparison. The demographic and hematologic variables and presence of the main autoantibodies in sera of 40 eligible ICU-hospitalized COVID-19 patients and 40 COVID-19 outpatients were assessed. Out of 108 COVID-19 ICU-hospitalized patients, 40 were selected as the control group (40/158) who had no underlying diseases before hospitalization, according to their self-declaration and clinical records at the time of admission. The results demonstrated that the main complete blood count indices, such as red blood cells and platelets, decreased dramatically in ICU-hospitalized patients. Furthermore, the autoantibody profiles were positive in 45% and 15% of ICU-admitted patients for antinuclear antibodies and antineutrophilic cytoplasmic autoantibodies, respectively. In ICU patients, anti-PM/Scl 100 or AMA-M2 was 33%. Anti SS-A, anti-SS-B, anti-Ro-52, and anti-Jo-1 in 11.5% for each one were reactive. Other autoantibodies of the ICU group were as follows: CENP (5.6%), Rib-protein (5.6%), and nucleosome (5.6%). However, only two individuals in the control group had positive results for SS-A and SS-B (5%). Induction of such particular autoantibodies by the virus can justify the multi-organ involvement and severity of the disease in ICU patients, which may also cause other organ involvement in the long term.

Bilateral Lower Extremity Edema of a Woman Aged 59 Years

&lt;p&gt;有許多病因會造成雙下肢水腫，心臟、肝臟、腎臟等相關疾病首先需被排除。本案例為一位罹患甲狀腺亢進的59歲女性、規則服用丙硫氧嘧啶（Propylthiouracil, PTU）兩年，以雙下肢水腫為最初表現，伴隨有血尿、蛋白尿及腎功能損傷，初始臆測是不明原因的腎絲球腎炎，經檢驗發現抗嗜中性球細胞質抗體（Antineutrophil Cytoplasmic Autoantibodies, ANCA）呈陽性反應， 最終透過腎臟切片，證實為PTU相關ANCA血管炎，予以停止PTU、給予類固醇治療後，腎功能獲得改善。針對此類個案無法以症狀及檢驗檢查確立診斷時，需安排被侵犯部位的切片檢查來協助診斷，當確定是藥物相關ANCA血管炎時， 應立即停藥，避免造成致命性的傷害。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;Many diseases may cause bilateral lower extremity edema. Diseases related to the heart, liver, and kidney shall be excluded first. The case of this study was a women aged 59 years with hyperthyroid&amp;shy;ism. The patient regularly took propylthiouracil (PTU) for 2 years. Bilateral lower extremity edema emerged as the first symptom, followed by hematuria, proteinuria, and impaired kidney functions. Initially, the medical team assumed the cause was glomerulonephritis with an unknown cause. After examination, the team discovered the patient was antineutrophil cytoplasmic autoantibodies (ANCA) positive. Through kidney biopsy, the team confirmed that the cause was PTU-related ANCA vascu&amp;shy;litis. Therefore the delivery of PTU was discontinued, and steroid treatment was administered. The patient&amp;rsquo;s kidney functions gradually improved. In similar cases where diagnosis cannot be confirmed through symptom interpretations or general examinations, biopsy of the infected area should be per&amp;shy;formed to confirm the diagnosis of the cause. When drug-related ANCA vasculitis is confirmed, the delivery of medicine must be suspended immediately to avoid further lethal damage.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;