A case of Podocytic Infolding Glomerulopathy with SLE and literature review

Background Podocytic infolding glomerulopathy (PIG) is a rare pathological change which was characterized by the microspheres or microtubular structures in the thickened glomerular basement membrane (GBM). Only a few dozen cases have been reported worldwide so far. Here we present a case of PIG with systemic lupus erythematosus. Case presentation A 61-year-old Chinese female was diagnosed with systemic lupus erythematosus with clinical manifestations of proteinuria, pleural effusion, seroperitoneum, anemia, leukopenia, thrombocytopenia, antinuclear antibody positive, and hypocomplementemia. She also had benign ovarian tumor and Epstein-Barr virus infection. Renal biopsy immunofluorescent staining showed IgM and C3 were granularly deposited along the capillary wall instead of typical “full house” features. Electron microscopy showed lots of microspheres structures were seen in the thickened GBM. Conclusion We present a case of PIG in a patient with systemic lupus erythematosus. The mechanisms of PIG are unknown, but may be associated with connective tissue disease and podocyte injury.

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

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.