Abstract: SA-PO175
Minimal Change Nephropathy as a First Manifestation of Waldenstrom Macroglobulinemia
Session Information
- Onco-Nephrology: Clinical
November 09, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onco-Nephrology
- 1500 Onco-Nephrology
Authors
- Pakchotanon, Kamolwan, Bhumibol Adulyadej hospital, Bangkok, Thailand
- Pattanachaiwit, Noppanit, Bhumibol Adulyadej hospital, Bangkok, Thailand
- Gojaseni, Pongsathorn, Bhumibol Adulyadej hospital, Bangkok, Thailand
- Worawichawong, Suchin, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
- Pakchotanon, Kolasorn, Bhumibol Adulyadej hospital, Bangkok, Thailand
Group or Team Name
- Bhumibol Adulyadej Hospital
Introduction
Waldenstrom’s macroglobulinemia (WM) is an uncommon disease, with rare renal presentation. We report a case of nephrotic syndrome (NS) resulting from minimal change nephropathy (MCN) as a first presentation of WM.
Case Description
A 60-year-old woman presented with progressive generalized edema over 3 months. Her physical examination showed severe edema in both legs and mildly pale conjunctiva. Urinalysis revealed 3+ protein with bland sediment. Urine protein creatinine ratio (UPCR) was 7.28. Blood tests were hemoglobin (Hb) 9.3 g/dL, Cr 1.48 mg/dL and serum albumin 1.7 g/dL. Serum protein electrophoresis had no signs of monoclonal gammopathy. Serum kappa/lambda ratio was 5.51. Bence-Jones proteinuria was negative. Renal biopsy revealed unremarkable glomerular capillaries and mesangium on light microscopy. An immunofluorescent study unveiled trace kappa and IgM. Electron microscopy showed diffuse foot process effacement without electron-dense deposits. This patient was given a diagnosis of MCN, and prednisolone was started. After 6 weeks of corticosteroid treatment, her clinical outcomes did not improve, with her anemia worsening. The results of further investigations showed immunofixation: IgM kappa monoclonal gammopathy. The bone marrow biopsy had 85% dense atypical small lymphoid cell infiltration. The WM diagnosis was rendered, and treatment instituted with rituximab, cyclophosphamide, vincristine, prednisolone (R-CVP). WM went into partial remission, and MCN was in complete remission (UPCR 0.22, Cr 0.7 mg/dL) after 5 courses of R-CVP.
Discussion
MCN’s good response to chemotherapy suggests a relationship between MCN and WM. However, the pathogenesis of MCN in WM remains unclear. It was suggested in cases of MCN associated with classic Hodgkin lymphoma that excessive production of inflammatory cytokines could alter the glomerular filtration barrier. An imbalance in T cell subpopulations, a significantly low ratio of CD4:CD8 and the decrease of T regulatory cells (Tregs), may be associated with the occurrence of MCN. More recently, clinical evidence of the effectiveness of B cell depletion via rituximab, an anti-CD20 monoclonal antibody, in different forms of NS has theorized a role for B cells as drivers of MCN. Moreover, targeting B cells may affect the cross-talk between T and B cells.