A Case of Podocytic Infolding Glomerulopathy in an Allograft Kidney

Podocytic infolding glomerulopathy (PIG) is a rare disease diagnosed by its characteristic structure on electron microscopy. Histologically, there are microtubules and microspheres in the glomerular basement membrane (GBM). Most PIG has been reported in Japan, with a single case in South Korea; there are no previous reports of PIG in kidney transplant patients. Here, we report a 47-year-old Korean woman diagnosed with PIG after a kidney transplant. She was diagnosed with systemic lupus erythematosus. She was suspected of having lupus nephritis and subsequently underwent kidney transplantation. Routine testing showed increased proteinuria without renal functional impairment. A biopsy of the allograft kidney revealed mild interstitial fibrosis, tubular atrophy, and GBM thickening with intramembranous microspherules and microtubules on light microscopy. Electron microscopy showed GBM thickening with intramembranous microspherules and microtubules. These findings are consistent with PIG.