2026-04-17T03:10:57Zhttps://recercat.cat/oai/request

oai:recercat.cat:11351/70542025-10-24T10:20:44Zcom_2072_378070com_2072_378040col_2072_378092

Crystal-Induced Podocytopathy Producing Collapsing Focal Segmental Glomerulosclerosis in Monoclonal Gammopathy of Renal Significance: A Case Report Buxeda, Anna Said, Samar Nasr, Samih H. Soler Romeo, Maria Jose Howard, Mathew T. Maguire, Leo J. Glomèruls renals - Malalties - Complicacions Gammapaties monoclonals - Complicacions DISEASES::Male Urogenital Diseases::Urologic Diseases::Kidney Diseases::Nephritis::Glomerulonephritis::Glomerulosclerosis, Focal Segmental Other subheadings::Other subheadings::Other subheadings::/complications DISEASES::Hemic and Lymphatic Diseases::Hematologic Diseases::Blood Protein Disorders::Hypergammaglobulinemia::Monoclonal Gammopathy of Undetermined Significance Other subheadings::Other subheadings::Other subheadings::/complications ENFERMEDADES::enfermedades urogenitales masculinas::enfermedades urológicas::enfermedades renales::nefritis::glomerulonefritis::glomeruloesclerosis focal Otros calificadores::Otros calificadores::Otros calificadores::/complicaciones ENFERMEDADES::enfermedades hematológicas y linfáticas::enfermedades hematológicas::trastornos de las proteínas sanguíneas::hipergammaglobulinemia::gammopatía monoclonal de relevancia indeterminada Otros calificadores::Otros calificadores::Otros calificadores::/complicaciones Glomeruloesclerosis focal y segmentaria; Queratopatía cristalina; Podocitopatía Glomeruloesclerosi focal i segmentària; Queratopatia cristal·lina; Podocitopatia Focal and segmental glomerulosclerosis; Crystalline keratopathy; Podocytopathy Monoclonal gammopathy–associated crystalline podocytopathy causing collapsing focal segmental glomerulosclerosis (FSGS) is very rare and has been associated with pamidronate therapy. We present the case of a 53-year-old man with vision loss secondary to corneal crystals deposition, nephrotic-range proteinuria, and reduced glomerular filtration rate without associated comorbid conditions. Two kidney biopsies were initially reported as primary FSGS but the patient did not respond to high-dose corticosteroid immunosuppression therapy. Re-review of biopsies with additional electron microscopy analysis revealed crystalline inclusions in podocytes leading to collapsing FSGS. Subsequent workup revealed an immunoglobulin G κ serum monoclonal protein. Bone marrow biopsy revealed 5% κ-restricted plasma cells with cytoplasmic crystalline inclusions. To our knowledge, this is the first case of monoclonal gammopathy of clinical significance manifesting as crystalline podocytopathy leading to collapsing FSGS and keratopathy leading to vision loss. Crystalline podocytopathy should be considered in the differential diagnosis of collapsing glomerulopathy, and careful ultrastructural examination of the kidney biopsy specimen is crucial to establish this diagnosis. The authors declare that they have no relevant financial interests. 2025-10-24T10:20:44Z 2025-10-24T10:20:44Z 2025-10-24T10:20:44Z 2022-02-22T07:41:55Z 2022-02-22T07:41:55Z 2021-07 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion http://hdl.handle.net/11351/7054 Kidney Medicine;3(4) https://doi.org/10.1016/j.xkme.2021.03.007 Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess Elsevier Scientia