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Abstract: TH-PO435

Unmasking a New Disease: Membranous Glomerulopathy With Masked IgG Kappa Deposits: A Case Report

Session Information

Category: Glomerular Diseases

  • 1301 Glomerular Diseases: Fibrosis and Extracellular Matrix


  • Alleyne, Saieda, WellSpan York Hospital Department of Internal Medicine, York, Pennsylvania, United States
  • Abdus Samad, Mohamed Anwar, WellSpan York Hospital Department of Internal Medicine, York, Pennsylvania, United States

Membranous-like glomerulopathy with masked IgG kappa [IgG-κ] deposits (MGMID) is a novel glomerular disease first described in 2014. By light microscopy and electron microscopy, it is indistinguishable from membranous nephropathy. MGMID is characterized by weak to negative immunoglobulin staining on routine immunofluorescence (IF) but strong IgG-κ restricted staining upon pronase digestion of formalin-fixed paraffin-embedded tissue. Here, we describe a case of membranous-like glomerulopathy with masked IgG-κdeposits found in a pregnant woman with nephrotic range proteinuria.

Case Description

34-year-old woman Gravida 2 Para 1 with history of hypertension was found to have 3+ proteinuria on routine prenatal work up at 11 weeks of gestation. Her urinalysis also showed microscopic hematuria and 24-hour urine proteinuria estimation revealed over 4 grams. She was also found to have mild hypoalbuminemia and hyperlipidemia. She did not have peripheral edema. She denied any history of kidney disease, preeclampsia or eclampsia with prior pregnancy or any miscarriages. Her CBC and kidney function were within normal limits. Subsequently serologic work up was sent which revealed weakly positive ANA ~1: 40 but negative anti double-stranded DNA, anti-PLA R2 antibody, ANCA, C3, C4, serum and urine protein electrophoresis, serum free light chain ratio. Relevant viral studies were negative. She then underwent a kidney biopsy which revealed MGMID. She deferred immunosuppressive therapy and chose to be managed conservatively with strict blood pressure and low salt diet.


There have been 14 cases documented of patients with MGMID in the literature associated with female patients less than 40 years of age with some form of autoimmune disease or hemolytic anemia. To our knowledge, this will be the first reported case in a pregnant woman. The etiology of the phenomenon is unknown however given this new discovery, continued documentation of these case presentations can aid in furthering research to investigate pathogenesis and subsequently treatment.