Abstract: SA-PO228
Proliferative Glomerulonephritis with Monoclonal Immunoglobulin M Deposits
Session Information
- Trainee Case Reports - V
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 1202 Glomerular Diseases: Immunology and Inflammation
Authors
- Shrestha, Sneha, Nyph/Weil Cornell Medical Center, New York, New York, United States
- Seshan, Surya V., Weill Cornell Medical Center, New York, New York, United States
- Chevalier, James M., Nyph/Weil Cornell Medical Center, New York, New York, United States
Introduction
Proliferative glomerulonephritis with monoclonal immunoglobulin G deposits (PGNMID) was first described as a distinct entity in 2004.Only few case reports of PGNMID with IgM or IgA dominant deposition have been described.Here we report our case with clinical and histopathological features of PGNMID with Ig M dominant deposit.
Case Description
A 37 year old gentleman with diabetes mellitus-type 2,hypertension and obesity,presented with leg swelling and foamy urine for two weeks.Clinical exam was significant for BP 155/97mmHg and 2+ pedal edema.Labs revealed elevated serum creatinine(1.28mg/dl, baseline 0.9mg/dl, peak over the course of follow up 6.26mg/dl) and albumin of 2.5gm/dl.Urinalysis showed specific gravity of 1.015,pH of 6.4, 4+ protein and 2+ blood,11-30 RBCs per hpf.Urine microalbumin to creatinine ratio was 5680 and urine protein creatinine ratio was 8gm per gm.Hemoglobin A1c was 6.8.There was no M spike.Serum free light chains were mildly elevated with normal ratio.Bone marrow biopsy did not show monoclonal plasmacytosis.Cryoglobulin levels were repeatedly normal.
Kidney biopsy showed moderately advanced diabetic nephropathy and nodular diabetic glomerulosclerosis, class III superimposed by IgM kappa proliferative glomerulonephritis.There was significant endocapillary and mesangial cellularity on light microscopy.Immunofluoroscence revealed granular 3+ IgM,3+ kappa light chain, 1-2+ C3 and 1-2+ C1q along the glomerular capillary walls and focally in the mesangium; and nonspecific 1+IgG, 1+ lambda and kappa light chains along the glomerular capillary walls,mesangial areas and tubular basement membrane.Electron microscopy showed scattered finely granular subendothelial electron dense deposits.
He was treated with statin,diuretics and ARB was added when creatinine stabilized. He was given pulse dose of iv steroids,plasmapheresis (to remove IgM) and iv rituximab. Since he did not respond,he was further treated with cyclophosphamide and mycophenolate mofetil with regression of proteinuria and creatinine improvement.
Discussion
PGNMID is characterized by immunofluorescence findings of monoclonal IgG deposits and electron-dense deposits (EDDs) localized to glomeruli.Our case with histopathological features of PGNMID but with Ig M deposits adds to handful of similar case reports.We propose expansion of Nasr et al’s classification to include IgM and IgA dominant variant.