Pathogenicity of Human anti-PLA2R1 Antibodies in Minipigs: A Pilot Study

TY - JOUR

T1 - Pathogenicity of Human anti-PLA2R1 Antibodies in Minipigs: A Pilot Study

AU - Reinhard, Linda

AU - Wiech, Thorsten

AU - Reitmeier, Aline

AU - Lassé, Moritz

AU - Machalitza, Maya

AU - Heumann, Asmus

AU - Ferru, Nicoletta

AU - Loreth, Desiree

AU - Schröder, Marie-Luise

AU - Hutzfeldt, Arvid

AU - Stahl, Felix R

AU - Peine, Sven

AU - Gröne, Hermann-Josef

AU - Meyer-Schwesinger, Catherine

AU - Rinschen, Markus M

AU - Stahl, Rolf A K

AU - Hoxha, Elion

N1 - Copyright © 2023 by the American Society of Nephrology.

PY - 2023/3/1

Y1 - 2023/3/1

N2 - SIGNIFICANCE STATEMENT: Membranous nephropathy (MN) is an autoimmune kidney disease characterized by immune deposits in the glomerular basement membrane. Circulating anti-phospholipase A 2 receptor 1 (PLA 2 R1) antibodies are detectable in 70%-80% of patients with MN, but experimental evidence of pathogenicity has been lacking. This study demonstrates the pathogenicity of human anti-PLA 2 R1 antibodies in minipigs, a model for MN that intrinsically expresses PLA 2 R1 on podocytes. After passive transfer of human anti-PLA 2 R1 antibody-containing plasma from patients with PLA 2 R1-associated MN to minipigs, antibodies were detected in the minipig glomeruli, but not in response to plasma from healthy controls. The minipigs developed histomorphological characteristics of MN, local complement activation in the glomeruli, and low-level proteinuria within 7 days, showing that human anti-PLA 2 R1 antibodies are pathogenic.BACKGROUND: Primary membranous nephropathy (MN) is an autoimmune kidney disease in which immune complexes are deposited beneath the epithelium in the glomeruli. The condition introduces a high risk for end-stage kidney disease. Seventy percent to 80% of patients with MN have circulating antibodies against phospholipase A 2 receptor 1 (PLA 2 R1), and levels correlate with treatment response and prognosis. However, experimental evidence that human anti-PLA 2 R1 antibodies induce MN has been elusive.METHODS: In passive transfer experiments, minipigs received plasma or purified IgG from patients with PLA 2 R1-associated MN or from healthy controls. Anti-PLA 2 R1 antibodies and proteinuria were monitored using Western blot, ELISA, and Coomassie staining. Kidney tissues were analyzed using immunohistochemistry, immunofluorescence, electron microscopy, and proteomic analyses.RESULTS: Minipigs, like humans, express PLA 2 R1 on podocytes. Human anti-PLA 2 R1 antibodies bound to minipig PLA 2 R1 in vitro and in vivo . Passive transfer of human anti-PLA 2 R1 antibodies from patients with PLA 2 R1-associated MN to minipigs led to histological characteristics of human early-stage MN, activation of components of the complement cascade, and low levels of proteinuria. We observed development of an autologous, later phase of disease.CONCLUSIONS: A translational approach from humans to minipigs showed that human anti-PLA 2 R1 antibodies are pathogenic in MN, although in the heterologous phase of disease only low-level proteinuria developed.

AB - SIGNIFICANCE STATEMENT: Membranous nephropathy (MN) is an autoimmune kidney disease characterized by immune deposits in the glomerular basement membrane. Circulating anti-phospholipase A 2 receptor 1 (PLA 2 R1) antibodies are detectable in 70%-80% of patients with MN, but experimental evidence of pathogenicity has been lacking. This study demonstrates the pathogenicity of human anti-PLA 2 R1 antibodies in minipigs, a model for MN that intrinsically expresses PLA 2 R1 on podocytes. After passive transfer of human anti-PLA 2 R1 antibody-containing plasma from patients with PLA 2 R1-associated MN to minipigs, antibodies were detected in the minipig glomeruli, but not in response to plasma from healthy controls. The minipigs developed histomorphological characteristics of MN, local complement activation in the glomeruli, and low-level proteinuria within 7 days, showing that human anti-PLA 2 R1 antibodies are pathogenic.BACKGROUND: Primary membranous nephropathy (MN) is an autoimmune kidney disease in which immune complexes are deposited beneath the epithelium in the glomeruli. The condition introduces a high risk for end-stage kidney disease. Seventy percent to 80% of patients with MN have circulating antibodies against phospholipase A 2 receptor 1 (PLA 2 R1), and levels correlate with treatment response and prognosis. However, experimental evidence that human anti-PLA 2 R1 antibodies induce MN has been elusive.METHODS: In passive transfer experiments, minipigs received plasma or purified IgG from patients with PLA 2 R1-associated MN or from healthy controls. Anti-PLA 2 R1 antibodies and proteinuria were monitored using Western blot, ELISA, and Coomassie staining. Kidney tissues were analyzed using immunohistochemistry, immunofluorescence, electron microscopy, and proteomic analyses.RESULTS: Minipigs, like humans, express PLA 2 R1 on podocytes. Human anti-PLA 2 R1 antibodies bound to minipig PLA 2 R1 in vitro and in vivo . Passive transfer of human anti-PLA 2 R1 antibodies from patients with PLA 2 R1-associated MN to minipigs led to histological characteristics of human early-stage MN, activation of components of the complement cascade, and low levels of proteinuria. We observed development of an autologous, later phase of disease.CONCLUSIONS: A translational approach from humans to minipigs showed that human anti-PLA 2 R1 antibodies are pathogenic in MN, although in the heterologous phase of disease only low-level proteinuria developed.

U2 - 10.1681/ASN.0000000000000068

DO - 10.1681/ASN.0000000000000068

M3 - Letter

C2 - 36735391

VL - 34

SP - 369

EP - 373

JO - J AM SOC NEPHROL

JF - J AM SOC NEPHROL

SN - 1046-6673

IS - 3

ER -