Abstract: TH-PO646

Natural History of Proliferative Glomerulonephritis with Monoclonal IgG Deposits: A Unique Case with 3 Renal Biopsies Obtained over 46 Years of Follow-Up

Session Information

Category: Nephrology Education

  • 1302 Fellows and Residents Case Reports

Authors

  • Aleter, Omar A., University of Texas Medical Branch, Galveston, Texas, United States
  • Afrouzian, Marjan, University of Texas Medical Branch, Galveston, Texas, United States
  • Badalamenti, John, University of Texas Medical Branch, Galveston, Texas, United States
  • Kassem, Hania, University of Texas Medical Branch, Galveston, Texas, United States
Background

Introduction: Proliferative Glomerulonephritis (GN) with Monoclonal IgG deposits (PGNMID) is a rare entity first described in 2004 by Nasr et al. Since then, only 49 cases have been reported. We present a case of PGNMID with recurrent hematuria and nephrotic range proteinuria with almost half a century of follow-up.

Methods

Case Description: 79 year old Caucasian female presents with a history of two separate episodes of biopsy-proven recurrent GN over a course of 46 years. Both biopsies from 1974, and 1987 were reported as Membranoproliferative GN. The patient presented in 2016 for the third time with symptoms of fluid overload, a slight worsening in renal function (creatinine increased from 1 to 1.3), 7grams of proteinuria along with glomerular hematuria. Serological work up including serum cryoglobulins, Hepatitis B and C, ANA, Anti DNA, Complement levels, and rheumatoid factor was negative. Serum and urine protein electrophoresis showed no M spike. The third kidney biopsy was performed.

Results

Pathology: Light microscopy revealed the following glomerular findings in 9 glomeruli: global sclerosis (1/9), segmental sclerosis (3/9), endocapillary proliferation (6/9) and double contours. Other findings included mild tubular atrophy, moderate interstitial inflammation and fibrosis, and mild arteriolar hyalinosis. By immunofluorescence microscopy (IF), 12 glomeruli showed severe (+++) staining with IgG (IgG3), C3 and Kappa, only. Electron microscopy (EM) showed intramembranous and mesangial electron dense deposits, spikes and massive subepithelial humps. None of the findings fit the diagnostic criteria for any glomerular disease caused by monoclonal deposits. The final diagnosis was PGNMID with monotypic IgG/Kappa deposits

Conclusion

Discussion: With 3 renal biopsies obtained over 46 years of follow-up, our case opens a unique window into the natural history, and most importantly the pathogenesis of PGNMID. The biopsies show the immunologic/morphologic evolution of PGNMID in the kidney, confirming the benign course of the entity and its slow progression as our patient did not develop any hematological malignancy and was treated only with ACE inhibitors.