Anti-ficolin-3 Autoantibodies in Lupus Nephritis

Study Overview
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Brief Summary
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Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of multiple autoantibodies. Antibodies against Ficolin-3 were previously identified in the sera of some SLE patients, but their prevalence and significance have not been yet investigated. The aims of this study were to determine the prevalence of anti-ficolin-3 antibodies among SLE patients and to investigate their potential as diagnostic and/or prognostic biomarkers in SLE. In this retrospective study, clinical data were obtained from medical files and blood samples were selected from preexisting biological collection. SLE patients (n=165) were informed and did not objected, they were matched to healthy controls (n=48). Disease activity was determined according to the SLEDAI score. Anti-ficolin-3, anti-dsDNA and anti-C1q antibodies levels were measured in sera by ELISA. First, a highly significant difference was found in the anti-ficolin-3 levels between SLE patients and healthy subjects. Anti-ficolin-3 antibodies were detected as positive in 58 of 165 (35%) SLE patients. The titer of anti-ficolin-3 antibodies was correlated with the SLEDAI score (p<0.0001). The presence of anti-ficolin-3 antibodies was associated with anti-C1q and anti-dsDNA antibodies. Regarding associations with clinical manifestations, only the presence of active lupus nephritis was significantly associated with the presence of anti-ficolin-3 antibodies (p=0.0001). This association with renal involvement was higher with anti-ficolin-3 antibodies than with other auto-antibodies. Interestingly, the combination of anti-ficolin-3 and anti-C1q antibodies demonstrated higher specificity than any other traditional biomarker. These results suggest that anti-ficolin-3 could be useful for the diagnosis of active nephritis in SLE patients.

Detailed Description
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For this retrospective study, a brief summary should be enough.

Official Title
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Association Between the Presence of Autoantibodies Targeting Ficolin-3 and Active Nephritis in Patients With Systemic Lupus Erythematosus

Conditions
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Lupus Erythematosus, Systemic

Intervention / Treatment
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* Other: Biological analysis


Participation Criteria
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Eligibility Criteria
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165 SLE patients Inclusion Criteria: Age: ≥ 18 years old Patients with lupus diagnostic criteria (ACR1997) Exclusion Criteria: Pregnant women Patient with known evolutive cancer 48 healthy patients matched in age and sex with one or several SLE patients

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| SLE patients<br>165 SLE patients. Subgroup : 77 with active lupus and 88 in disease remission. in the active subgroup : 36 with lupus nephritis and 41 without. Biological analysis were performed. | Other: Biological analysis<br>* Biological analysis : ficolin-3 anti-ficolin 3 antibodies anti-C1q antibodies<br>* Other names: Biological analysis on pre-existing serum collection;|
| healthy patients<br>48 healthy patients. Biological analysis were performed. | Other: Biological analysis<br>* Biological analysis : ficolin-3 anti-ficolin 3 antibodies anti-C1q antibodies<br>* Other names: Biological analysis on pre-existing serum collection;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Anti-ficolin-3 antibodies presence in SLE patients | Anti-ficolin-3 antibodies in SLE patients, considered positive if superior than 70 arbitrary units. This study have a single visit approach with serum collection so every outcome is measured at T0, which is the only visit for the patient. | measured at day of inclusion = T0. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Correlation of anti-ficolin-3 antibodies with anti-DNA antibodies in SLE patients | This study have a single visit approach with serum collection so every outcome is measured at T0, which is the only visit for the patient. | measured at day of inclusion = T0. | 
| Correlation of anti-ficolin-3 antibodies with anti-C1q antibodies in SLE patients | This study have a single visit approach with serum collection so every outcome is measured at T0, which is the only visit for the patient. | measured at day of inclusion = T0. | 
| Correlation of anti-ficolin-3 antibodies with lupus activity (SLEDAI score) in SLE patients | This study have a single visit approach with serum collection so every outcome is measured at T0, which is the only visit for the patient. | measured at day of inclusion = T0. | 
| Anti-ficolin-3 antibodies presence in SLE patients with active nephritis | This study have a single visit approach with serum collection so every outcome is measured at T0, which is the only visit for the patient. | measured at day of inclusion = T0. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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ficolin-3, anti-ficolin-3 antibodies, lupus nephritis, Lupus Erythematosus, Systemic, biomarker