Abstract: TH-PO813
Infection as a Trigger of Acute, Transient Glomerular Deposition of Clonal Immunoglobulins
Session Information
- Pathology and Lab Medicine - I
November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Pathology and Lab Medicine
- 1800 Pathology and Lab Medicine
Authors
- Wang, Bangchen, Duke University, Durham, North Carolina, United States
- Schub, Micah, Duke University, Durham, North Carolina, United States
- Robinson, Derrick, Novant Health, Wilmington, North Carolina, United States
- Howell, David Noble, Duke University, Durham, North Carolina, United States
Introduction
Glomerular deposition of clonal IgM, frequently in the form of intracapillary pseudothrombi, can be seen in Waldenström macroglobulinemia (WM) and type 1 cryoglobulinemia (CG). Both are typically associated with B-cell lymphomas, particularly lymphoplasmacytic lymphoma (LPL). While infection is a frequent trigger of mixed (type 2 and 3) CG, its association with type 1 CG is uncommon. We report two cases in which striking lambda-restricted IgM deposits and acute kidney injury (AKI) occurred in the setting of systemic infections, with prompt resolution on treatment of the infection.
Case Description
Patient 1 was a 57-year-old female who presented with AKI following bowel perforation, treated with resection and antibiotics. Serum protein electrophoresis (SPEP) showed IgG kappa and IgM lambda M-proteins, without history of lymphoma. Patient 2 was a 59-year-old female with a 9-year history of an untreated, quiescent mature B-cell lymphoma, who presented with AKI, nephrotic range proteinuria, and hematuria, alongside a recent sore throat, presumptively treated with antibiotics for a respiratory infection. Her lab findings showed hypocomplementemia and faint IgM-lambda M-protein on SPEP. Neither patient was tested for cryoglobulins. Renal biopsies for both patients revealed glomerular capillary loops distended by abundant amorphous, eosinophilic and PAS-positive material, which stained strongly for IgM and lambda light chain on immunofluorescence and was granular and lacked substructure by electron microscopy. These findings were initially interpreted as concerning for renal manifestations of WM. However, after further investigation, neither patient exhibited LPL, and both patients experienced recovery of renal function following treatment of their respective infections (patient 2 also received a short course of steroids). Notably, patient 1 was diagnosed with a diffuse large B-cell lymphoma several years later.
Discussion
While infection may not be the root cause of clonal immunoglobulin production, these two cases suggest that it may serve as a trigger for glomerular deposition of clonal IgM in patients predisposed by underlying lymphoma. WM was initially suspected in both patients; however, the rapid normalization of renal function after resolution of infection indicates that they had undiagnosed type 1 CG triggered by infection.