Autoantibodies Against-nephrin in Idiopathic Nephrotic Syndrome

Nephrotic Syndrome Clinical Trial

— BLINDER  

Official title:

Autoantibodies Against-nephrin in Idiopathic Nephrotic Syndrome

Clinical Trial Details — Status: Not yet recruiting

Administrative data

• NCT number: NCT06334692
• Other study ID #: BLINDER
• Status: Not yet recruiting
• Start date: May 2024
• Est. completion date: May 2028

Study information

• Verified date: April 2024
• Source: Mario Negri Institute for Pharmacological Research
• Contact: Federica Casiraghi, PhD
• Phone: +3903545351
• Email: federica.casiraghi[@]marionegri.it
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

This retrospective study is aimed at evaluating the levels of circulating anti-nephrin autoantibodies in patients with INS, including those with MCD/FSGS and in patients who have experienced relapse of FSGS post-transplant, compared to those of a control group of patients with nephrotic syndrome due to primary membranous nephropathy (MN).

Description:

Nephrotic syndrome (NS) is one of the major "unsolved problems" in nephrology and represents a long-standing challenge in terms of pathogenetic mechanisms and the search for an effective cure. Nephrotic-range proteinuria (>3.5 g/day) is accompanied by a set of abnormalities collectively known as NS. It is characterized by systemic complications resulting from alterations in the composition of the body's protein pool, sodium retention, dyslipidemia, coagulation factor abnormalities and a variable degree of renal failure. When secondary causes cannot be identified, the clinical presentation is called idiopathic nephrotic syndrome (INS). INS is associated with disappearance of podocyte pedicels (visible under the electron microscope) and minimal changes (minimal change disease, MCD) or, at the more advanced stage, focal segmental glomerulosclerosis (FSGS) under the light microscope. INS can be treated with corticosteroids, which represent the first-line treatment, however, among the forms of NS, FSGS has the lowest rate of response to therapy. More importantly, in 30% of patients with FSGS, disease recurrence develops rapidly after transplantation, sometimes within minutes or hours, and leads to the immediate onset of proteinuria and graft dysfunction. For post-transplant FSGS recurrence, no prevention or treatment strategies are available and current therapeutic approaches are mostly based on clinical experience. The recurrence of FSGS in the transplanted kidney presupposes the presence of one or more circulating factors of extrarenal origin which can selectively affect and damage the glomerular barrier, in particular the podocytes, resulting in massive proteinuria. However, the identity, nature and cellular source of factors circulating in the INS are not yet known. Recent evidence of the therapeutic efficacy of anti-B cell antibodies in inducing and/or maintaining remission in patients with INS indicates the presence of possible B cell dysfunction. In support of this, a recent study described the presence of anti-nephrin autoantibodies (a structural component of the podocyte slit diaphragm) in a subgroup of pediatric and adult patients with MCD. These autoantibodies were present during the active phase of the disease, and were associated with a punctate staining of IgG in renal biopsies in correspondence with the specific areas of presence of nephrin. Furthermore, the presence of autoantibodies against nephrin has been found in early post-transplant FSGS recurrence. This preliminary result was confirmed by a Japanese multicenter study conducted on 11 pediatric patients with post-transplant FSGS recurrence. In these patients, anti-nephrin autoantibodies were elevated both before transplantation and during disease relapse and were related to punctate deposition of immunoglobulins G (IgG) that colocalized with nephrin in the graft biopsy at the time of relapse. This recent evidence suggests that circulating anti-nephrin antibodies represent a possible circulating factor involved in the pathogenesis of INS, in particular post-transplant FSGS recurrence.

Recruitment information / eligibility

• Status: Not yet recruiting
• Enrollment: 100
• Est. completion date: May 2028
• Est. primary completion date: May 2028
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Adult (>18 years) males and females
• Patients with biopsy-proven idiopathic MCD or FSGS (cases)
• Patients with biopsy-proven idiopathic membranous nephropathy (controls)
• Patients who provided consent to store their samples in the certified CRB biobank

Exclusion Criteria:

• Reasonable possibility of a secondary cause of NS (for cases) or MN (for controls) at time of blood collections
• Active viral or bacterial infections at time of blood collections

Related Conditions & MeSH terms

• Nephrosis
• Nephrotic Syndrome
• Syndrome

Intervention

Diagnostic Test:
• In-house ELISA, and ELISA kits from "DBA Italy" (Abbexa).
"Nunc MaxiSorp" ELISA plates will be coated with recombinant extracellular domain of human nephrin. Patient serum samples will be added in appropriate dilution. Plates will be then incubated with biotin-conjugated anti human IgG antibody followed by incubation with horseradish peroxidase (HRP)-avidin conjugate. Then tetramethylbenzidine substrate will be added, and absorbance read at 450 nm.

Locations

Country	Name	City	State
Italy	Clinical Research Center for Rare Disease Aldo e Cele Daccò	Ranica	BG

Sponsors (1)

Lead Sponsor	Collaborator
Mario Negri Institute for Pharmacological Research

Country where clinical trial is conducted

Italy, 

References & Publications (9)

Casiraghi F, Todeschini M, Podesta MA, Mister M, Ruggiero B, Trillini M, Carrara C, Diadei O, Villa A, Benigni A, Remuzzi G. Immunophenotypic Alterations in Adult Patients with Steroid-Dependent and Frequently Relapsing Nephrotic Syndrome. Int J Mol Sci. 2023 Apr 22;24(9):7687. doi: 10.3390/ijms24097687. — View Citation

D'Agati VD, Kaskel FJ, Falk RJ. Focal segmental glomerulosclerosis. N Engl J Med. 2011 Dec 22;365(25):2398-411. doi: 10.1056/NEJMra1106556. No abstract available. — View Citation

Gallon L, Leventhal J, Skaro A, Kanwar Y, Alvarado A. Resolution of recurrent focal segmental glomerulosclerosis after retransplantation. N Engl J Med. 2012 Apr 26;366(17):1648-9. doi: 10.1056/NEJMc1202500. No abstract available. — View Citation

Maas RJ, Deegens JK, Smeets B, Moeller MJ, Wetzels JF. Minimal change disease and idiopathic FSGS: manifestations of the same disease. Nat Rev Nephrol. 2016 Dec;12(12):768-776. doi: 10.1038/nrneph.2016.147. Epub 2016 Oct 17. — View Citation

McCarthy ET, Sharma M, Savin VJ. Circulating permeability factors in idiopathic nephrotic syndrome and focal segmental glomerulosclerosis. Clin J Am Soc Nephrol. 2010 Nov;5(11):2115-21. doi: 10.2215/CJN.03800609. Epub 2010 Oct 21. — View Citation

Ruggenenti P, Ruggiero B, Cravedi P, Vivarelli M, Massella L, Marasa M, Chianca A, Rubis N, Ene-Iordache B, Rudnicki M, Pollastro RM, Capasso G, Pisani A, Pennesi M, Emma F, Remuzzi G; Rituximab in Nephrotic Syndrome of Steroid-Dependent or Frequently Relapsing Minimal Change Disease Or Focal Segmental Glomerulosclerosis (NEMO) Study Group. Rituximab in steroid-dependent or frequently relapsing idiopathic nephrotic syndrome. J Am Soc Nephrol. 2014 Apr;25(4):850-63. doi: 10.1681/ASN.2013030251. Epub 2014 Jan 30. — View Citation

Salfi G, Casiraghi F, Remuzzi G. Current understanding of the molecular mechanisms of circulating permeability factor in focal segmental glomerulosclerosis. Front Immunol. 2023 Sep 19;14:1247606. doi: 10.3389/fimmu.2023.1247606. eCollection 2023. — View Citation

Shirai Y, Miura K, Ishizuka K, Ando T, Kanda S, Hashimoto J, Hamasaki Y, Hotta K, Ito N, Honda K, Tanabe K, Takano T, Hattori M. A multi-institutional study found a possible role of anti-nephrin antibodies in post-transplant focal segmental glomerulosclerosis recurrence. Kidney Int. 2024 Mar;105(3):608-617. doi: 10.1016/j.kint.2023.11.022. Epub 2023 Dec 16. — View Citation

Watts AJB, Keller KH, Lerner G, Rosales I, Collins AB, Sekulic M, Waikar SS, Chandraker A, Riella LV, Alexander MP, Troost JP, Chen J, Fermin D, Yee JL, Sampson MG, Beck LH Jr, Henderson JM, Greka A, Rennke HG, Weins A. Discovery of Autoantibodies Targeting Nephrin in Minimal Change Disease Supports a Novel Autoimmune Etiology. J Am Soc Nephrol. 2022 Jan;33(1):238-252. doi: 10.1681/ASN.2021060794. Epub 2021 Nov 3. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Levels of circulating anti-nephrin autoantibodies	Serum samples will be tested for the levels of anti-nephrin autoantibodies by in-house ELISA and results confirmed by commercial ELISA kits.	At 1 year. Given the retrospective nature of the study, the indicated time frame refers to the time required to perform the analysis, i.e to assess levels of anti-nephrin antibodies in patients with NS compared to controls.