Diagnostic Performance of a Commercial Assay for the Detection of Neuronal Antibodies

Study Overview
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Brief Summary
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Detection of autoantibodies targeting neuronal surface or intracellular antigens is a keystone for the diagnosis and the treatment of auto-immune encephalitis and paraneoplastic neurological syndromes. A strategy commonly used for their detection is to perform a screening with a tissue-based immunofluorescence assay or immunohistochemistry assay and a second line test to confirm and identify the autoantibody. Since several years, commercial kits are used by a growing number of laboratories to screen the presence of these autoantibodies. However, the diagnostic performance of these commercial kits is highly variable and several studies reported a high prevalence of false-positive and false-negative results with commercial immunodots and cell-based assays. It is therefore essential to explore commercial kits limitations in order to avoid false-positive and false-negative results that could lead to misdiagnosis and/or to delay the treatments. To assess the diagnostic performance of commercial kits, the investigators performed a prospective study in which the investigators screened patients neuronal autoantibodies in cerebrospinal fluid and sera using commercial tissue-based indirect immunofluorescence assay and CBAs in comparison with an in-house tissue-based indirect immunofluorescence assay.

Official Title
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Diagnostic Performance of a Commercial Indirect Immunofluorescence Assay for the Detection of Neuronal Antibodies in Auto-immune Encephalitis and Paraneoplastic Neurological Syndromes

Conditions
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Paraneoplastic Neurological Syndrome, Autoimmune Encephalitis

Intervention / Treatment
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* Diagnostic Test: Indirect immunofluorescence assay on tissue slides and cell-based assays with CSF and/or sera


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria * : Sera and/or CSF with sufficient volume to perform both in-house and commercial assays Exclusion Criteria * : Sera and/or CSF with insufficient volume to perform both in-house and commercial assays
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 |
| --- | --- |
| Suspicion of autoimmune neurological disorder<br>Sera and CSF of patients with a suspicion of autoimmune encephalitis or paraneoplastic neurological syndrome | Diagnostic Test: Indirect immunofluorescence assay on tissue slides and cell-based assays with CSF and/or sera<br>* Sera and/or CSF samples are drawn from patients with a clinical suspicion of autoimmune encephalitis or paraneoplastic neurological syndrome. Indirect immunofluorescence assays will be performed on commercial and in-house slides upon receipt in our center. In case of positive staining, additional tests such as cell-based assays, western-blots, ELISA or immunodots can be performed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of discrepant results between commercial and in-house assays | Both in-house and commercial assays will be performed independently and results will be compared once all tests are done. Number of discrepant results will be compared with concordant results according to the autoantibody identified. | at the baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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autoantibodies, diagnostic, paraneoplastic, encephalitis, neuronal