Abstract: SA-PO174
Autologous Stem Cell Transplant for the Treatment of Masked Crystalline Light Chain Tubulopathy and Podocytopathy Causing FSGS in the Context of Monoclonal Gammopathy of Renal Significance
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
- Kousios, Andreas, Imperial College Healthcare NHS Trust, London, United Kingdom
- McAdoo, Stephen Paul, Imperial College Healthcare NHS Trust, London, United Kingdom
- Blakey, Sarah, Imperial College Healthcare NHS Trust, London, United Kingdom
- Atta, Maria, Imperial College Healthcare NHS Trust, London, United Kingdom
- Duncan, Neill D., Imperial College Healthcare NHS Trust, London, United Kingdom
- Tam, Frederick W.K., Imperial College Healthcare NHS Trust, London, United Kingdom
- Cook, H. Terence, Imperial College Healthcare NHS Trust, London, United Kingdom
- Roufosse, Candice A., Imperial College Healthcare NHS Trust, London, United Kingdom
- Chaidos, Aristeidis, Imperial College Healthcare NHS Trust, London, United Kingdom
Group or Team Name
- Imperial College Healthcare NHS Trust
Introduction
<p style="margin: 0px 0px 13.33px;"><font color="#000000" face="Calibri" size="3"> MGRS encompasses a wide spectrum of renal histopathology. Light chain (LC) crystalline podocytopahty causing secondary FSGS has rarely been described. We present a case with masked crystalline tubulopathy and podocytopathy associated with MGRS which was treated with myeloma induction therapy followed by autologous stem cell transplantation (ASCT). </font></p>
Case Description
A 47 year old male presented with nephrotic proteinuria (uPCR 760 mg/mmol), microscopic haematuria and renal impairment (Creatinine 146umol/l, eGFR 49ml/min). Autoimmune, virology screen, Complement were normal. Protein electrophoresis (SPEP) showed IgG kappa paraprotein 11g/l. Serum free light chain (SFLC) ratio was 9.5 (kappa level 91.3mg/l, lambda 9.6mg/l). No cryoglobulin was detected. Renal biopsy showed features of secondary FSGS. Immunofluorescence (IF) was negative for IgG, IgM, IgA, c3, c1q and equal kappa/lambda staining. We performed IF on paraffin sections after protease digestion unmasking crystalline inclusions in podocytes and tubules showing kappa LC restriction. Bone marrow biopsy (BMAT) showed 10-12% plasma cells. Normal skeletal survey. In conjunction, BMAT and renal biopsy results were in keeping with MGRS with an unusual histology of masked FLC-crystalline in tubules and podocytes causing FSGS. Treatment included VCD chemotherapy with partial response followed by melphalan conditioned ASCT. One month post ASCT renal function and proteinuria improved(Creatinine 120 umol/l, eGFR 60 ml/min).
Discussion
<p style="margin: 0px 0px 13.33px;"><font color="#000000" face="Calibri" size="3">MGRS must be suspected in all patients with kidney disease and paraprotein regardless of the tumour burden.<span style="margin:0px"> </span>Protease digestion may be needed to unmask FLC restriction and should be considered in selected cases. Effective haematological treatment improved renal outcome. </font></p>