ArticleFrontiers in immunology2019
Novel Assays to Distinguish Between Properdin-Dependent and Properdin-Independent C3 Nephritic Factors Provide Insight Into Properdin-Inhibiting Therapy.
Article in Frontiers in immunology, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 15 papers, 1 of them a synthesis that pooled it.
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Who cites it
15 citing papers in PubMed, 1 synthesis or guideline pooled it, 20 citations in OpenAlex.
- Pooled it
- Characterizing Properdin-Inhibited C3 Nephritic Factors in Patients with Complement-Mediated Kidney Diseases.International journal of molecular sciences · 2026Article
- Acquired drivers of C3 glomerulopathy.Clinical kidney journal · 2025Review
- Seventy Years Later: Systemic and Local Properdin in Atherosclerosis.Journal of the American Heart Association · 2025Article
- Glycoproteomics analysis of complement factor H and its complement-regulatory function duringFrontiers in immunology · 2025Article
- Defining Nephritic Factors as Diverse Drivers of Systemic Complement Dysregulation in C3 Glomerulopathy.Kidney international reports · 2024Article
- A Monoclonal Antibody That Provides a Model for C3 Nephritic Factors.Monoclonal antibodies in immunodiagnosis and immunotherapy · 2023Article
- Initial properdin binding contributes to alternative pathway activation at the surface of viable and necrotic cells.European journal of immunology · 2022Article
- Long-term follow-up including extensive complement analysis of a pediatric C3 glomerulopathy cohort.Pediatric nephrology (Berlin, Germany) · 2022Article
- Structure and function of a family of tick-derived complement inhibitors targeting properdin.Nature communications · 2022Article
- Challenges in diagnostic testing of nephritic factors.Frontiers in immunology · 2022Review
- Exploring urine:serum fractional excretion ratios as potential biomarkers for lupus nephritis.Frontiers in immunology · 2022Article
- Different Aspects of Classical Pathway Overactivation in Patients With C3 Glomerulopathy and Immune Complex-Mediated Membranoproliferative Glomerulonephritis.Frontiers in immunology · 2021Article
- Properdin Pattern Recognition on Proximal Tubular Cells Is Heparan Sulfate/Syndecan-1 but Not C3b Dependent and Can Be Blocked by Tick Protein Salp20.Frontiers in immunology · 2020Article
- Insights Into Enhanced Complement Activation by Structures of Properdin and Its Complex With the C-Terminal Domain of C3b.Frontiers in immunology · 2019Article
Corrections and comments
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Authors and funding
10 authors at 6 institutions in 2 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
C3 glomerulopathy (C3G) is an umbrella classification for severe renal diseases characterized by predominant staining for complement component C3 in the glomeruli. The disease is caused by a dysregulation of the alternative pathway (AP) of the complement system. In more than half of C3G patients C3 nephritic factors (C3NeFs) are found. These autoantibodies bind to the AP C3 convertase, prolonging its activity. C3NeFs can be dependent or independent of the complement regulator properdin for their convertase-stabilizing function. However, studies to determine the properdin-dependency of C3NeFs are rare and not part of routine patient workup. Until recently, only supportive treatments for C3G were available. Complement-directed therapies are now being investigated. We hypothesized that patients with properdin-dependent C3NeFs may benefit from properdin-inhibiting therapy to normalize convertase activity. Therefore, in this study we validated two methods to distinguish between properdin-dependent and properdin-independent C3NeFs. These methods are hemolytic assays for measuring convertase activity and stability in absence of properdin. The first assay assesses convertase stabilization by patient immunoglobulins in properdin-depleted serum. The second assay measures convertase stabilization directly in patient serum supplemented with the properdin-blocking agent Salp20. Blood samples from 13 C3NeF-positive C3G patients were tested. Three patients were found to have properdin-dependent C3NeFs, whereas the C3NeF activity of the other ten patients was independent of properdin. The convertase-stabilizing activity in the samples of the patients with properdin-dependent C3NeFs disappeared in absence of properdin. These data indicate that inhibition of properdin in patients with properdin-dependent C3NeFs can normalize convertase activity and could represent a novel therapy for normalizing AP hyperactivity. Our assays provide a tool for identifying C3G patients who may benefit from properdin-inhibiting therapy and can be incorporated into standard C3G laboratory investigations.
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