Crystalline podocytopathy and tubulopathy without overt glomerular proteinuria in a patient with multiple myeloma

Abstract

Crystalline nephropathy is a rare yet well-known condition associated with multiple myeloma and other light chain–secreting disorders. Paraproteins that are resistant to proteolysis crystallize within proximal tubular cells and cause light-chain proximal tubulopathy, which presents clinically as Fanconi syndrome. Podocytes are rarely affected, and the crystalline inclusions within podocytes are typically precipitated, yielding significant glomerular proteinuria. Here we report a case of extensive crystalline inclusions primarily within podocytes and proximal tubules that presented only with Fanconi syndrome and renal insufficiency. Despite the presence of extensive crystalline inclusions in podocytes and diffuse foot process effacement, the patient had no clinical evidence suggestive of podocyte injury.

Monoclonal light chain crystalline podocytopathy and tubulopathy associated with monoclonal gammopathy of renal significance: a case report and literature review

“…Multiple myeloma patients should be treated with chemotherapy to improve survival, but whether the chemotherapy would prevent renal progression is unclear. However, some previous reports have shown decreased proteinuria and serum creatinine as well as hematological remission after chemotherapy [ 9 , 11 , 15 ], suggesting a benefit of chemotherapy for these patients This case was treated with standard bortezomib followed by lenalidomide-based chemotherapy, and her renal function was stable with a significant decrease in proteinuria after 1 year of follow-up.…”

Crystal-Induced Podocytopathy Producing Collapsing Focal Segmental Glomerulosclerosis in Monoclonal Gammopathy of Renal Significance: A Case Report

“…To date, only 17 cases in native kidneys have been reported in the English literature. Of these, 12 patients had multiple myelomas 7 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 and only 5 had MGRS 22 , 23 , 24 , 25 , 26 ( Table S1 ). Interestingly, all cases (this case included) were associated with IgGκ serum paraprotein.…”

Light Chain Crystal Podocytopathy in a Patient With Systemic Indolent B-Cell Lymphoma

“…These crystals, most often within proximal tubular epithelial cells where filtered light chains are reabsorbed, lead to tubular injury and renal dysfunction (light chain proximal tubulopathy [LCPT]) that usually manifests as Fanconi syndrome. 4 Other intrarenal intracellular inclusions are even less commonly found in podocytes (light chain crystal podocytopathy [LCCP]), interstitial histiocytes (crystal-storing histiocytosis), endothelial cells, mesangial cells, and intravascularly (crystalglobinemia). 3,4 There are only a handful of reported cases of LCCP, in which patients present with proteinuria and renal insufficiency, and with concomitant LCPT.…”

“…4 Other intrarenal intracellular inclusions are even less commonly found in podocytes (light chain crystal podocytopathy [LCCP]), interstitial histiocytes (crystal-storing histiocytosis), endothelial cells, mesangial cells, and intravascularly (crystalglobinemia). 3,4 There are only a handful of reported cases of LCCP, in which patients present with proteinuria and renal insufficiency, and with concomitant LCPT. 5,6 No previous cases have described this phenomenon in the setting of lymphoma (as opposed to plasma cell dyscrasia).…”