Evaluation of Anti-neutrophil Cytoplasm Antibodies Test

Study Overview
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Brief Summary
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Anti-neutrophil cytoplasm antibodies (ANCA) are defined as important serological markers for the diagnosis of some forms of small vessel vasculitis, including granulomatosis with polyangiitis (GPA) , microscopic polyangiitis(MPA) and to a lesser extent Churg -Strauss syndrome or Eosinophilic granulomatosis with polyangiitis (EGPA).So they are called ANCA-associated vasculitis(AAV). An international consensus statement for ANCA testing statement was issued in 2017 and states that the antigen specific immunoassays can be used for the accurate diagnosis of ANCA-associated vasculitis without the need for indirect immunofluorescence(IIF). In the present study we will test whether the antigen specific assays screening is a valuable alternative to IIF confirming with immunoassay for the diagnosis of AAV on a number of patients and controls. Aim To evaluate the performance of the recommended strategy for the detection of ANCA based on screening with antigen specific immunoassays on a number of AAV patients and relevant disease controls In Kagawa university hospital (rheumatology department). Patients and methods This is a prospective study will be conducted at the department of rheumatology in Kagawa university hospital in which consecutive samples will be included from patients suspected to have AAV; patients subsequently identified as having AAV will be included as AAV patients, while patients in which the diagnosis AAV is rejected, will be included as disease controls. PR3-and MPO-ANCA will be performed using assays from Medical & Biological Laboratories Co (Anchor CLEIA) isayama.takuya@mbl.co.jp

Detailed Description
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To evaluate the performance of the recommended strategy for the detection of ANCA based on screening with antigen specific immunoassays on a number of AAV patients and relevant disease controls (i. e., patients for whom ANCA would be requested in the context of small-vessel vasculitis such as patients with infections, drug-induced diseases, connective tissue disease, etc.).

Official Title
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Evaluation of ANCA Testing by Antigen Specific Assays in Small Vessel Vasculitis

Conditions
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Immunological Testing in Small-vessel Vasculitis

Intervention / Treatment
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* Diagnostic Test: Indirect immunofluorescence (IIF) , myeloperoxidase antibody(MPO)- and anti-proteinase 3 (PR3-) ANCA immunoassays


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: .All patients included must be older than 18 years and able to give informed consent. Classification criteria and nomenclature for AAV are from the American College of Rheumatology Serum sampling should be done before initiation of immunosuppressive treatment or no later than 2 weeks after onset of low-medium dose of immunosuppressive treatment (but this should be documented) Exclusion Criteria: .Patients younger than 18 years old

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Cases with ANCA vasculitis<br>Indirect immunofluorescence (IIF) will be performed as well as myeloperoxidase antibody(MPO)- and anti-proteinase 3 (PR3-) ANCA immunoassays and evaluated | Diagnostic Test: Indirect immunofluorescence (IIF) , myeloperoxidase antibody(MPO)- and anti-proteinase 3 (PR3-) ANCA immunoassays<br>* Measurement and evaluation of the ANCA testing<br>|
| Controls with autoimmune diseases other than ANCA vasculitis<br>Indirect immunofluorescence (IIF) will be performed as well as myeloperoxidase antibody(MPO)- and anti-proteinase 3 (PR3-) ANCA immunoassays and evaluated | Diagnostic Test: Indirect immunofluorescence (IIF) , myeloperoxidase antibody(MPO)- and anti-proteinase 3 (PR3-) ANCA immunoassays<br>* Measurement and evaluation of the ANCA testing<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anti-proteinase 3 antibody (PR3), anti-myeloperoxidase (MPO) antibody presence in patients with small-vessel vasculitis versus patients without vasculitis | Antibodies are detected using chemiluminescent enzyme immunoassay (CLEIA).Values above 3.5 u/ml are considered positive | within two weeks of immunosuppressive treatment not after that | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ANCA vasculitis, ANCA testing, antigen specific essays, IIF