Podocytic Infolding Glomerulopathy in a Patient with Phospholipase A2 Receptor-Positive Membranous Nephropathy and Review of the Literature

• Published in: Nephron (2015) Vol. 145; no. 5; p. 496
• Main Authors: Pandit, Amar P, Rennke, Helmut G, Denker, Bradley M
• Format: Journal Article
• Language: English
• Published: Switzerland 2021
• Subjects: Female; Glomerulonephritis, Membranous - diagnosis; Glomerulonephritis, Membranous - drug therapy; Glomerulonephritis, Membranous - enzymology; Glomerulonephritis, Membranous - pathology; Humans; Kidney Glomerulus - pathology; Kidney Glomerulus - ultrastructure; Microscopy, Electron; Middle Aged; Podocytes - pathology; Receptors, Phospholipase A2 - metabolism; Rituximab - therapeutic use; Rituximab; Antiphospholipid A2 receptor antibodies; Membranous nephropathy; Podocytic infolding
• DOI: 10.1159/000515769

Podocytic infolding glomerulopathy (PIG) is a rare diagnosis based on characteristic histopathologic findings on renal biopsy and was proposed as a new entity about a decade ago. It is a type of podocytic injury, characterized by invagination of the podocyte cell membrane (cytoplasmic projections from podocytes) into the glomerular basement membrane. The presence of microspheres and/or microtubules on electron microscopy is the characteristic finding. PIG is most often associated with autoimmune conditions like systemic lupus erythematosus. We report pathologic findings typical of PIG in a patient with phospholipase A2 receptor antibody-positive membranous nephropathy. She was treated with rituximab and responded well with decrease in proteinuria to the sub-nephrotic range.