Abstract: SA-PO846
A Case of Heavy Chain Deposition Disease
Session Information
- C3G, TMA, MGRS, Amyloidosis, and More
October 26, 2024 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Teferici, Stela, Elmhurst Hospital - Main Campus, Elmhurst, New York, United States
- Stern, Aaron S., Elmhurst Hospital - Main Campus, Elmhurst, New York, United States
- Munoz Casablanca, Nitzy N., Elmhurst Hospital - Main Campus, Elmhurst, New York, United States
Introduction
Monoclonal Immune Deposition Disease (MIDD) is a rare manifestation of monoclonal gammopathy of renal significance, with non-organized deposition of monoclonal proteins in the glomerulus. Deposition that only involves the heavy chain portion of a monoclonal immunoglobin is even rarer. We present a case of Heavy Chain Deposition Disease (HCDD).
Case Description
A 61-year-old female was referred to our clinic for edema and nephrotic syndrome. She had facial and pedal edema, hypoalbuminemia and a Urine Protein/Creatinine Ratio of 4. Further work-up revealed antinuclear antibody: 1: 320, Complement 3: 72mg/dL (mildly low), Complement 4: 32mg/dL (normal), Serum protein electrophoresis (SPEP) had a weak gamma paraprotein, Immunofixation electrophoresis (IFE) was positive for immunoglobulin G (IgG) kappa. Serum free light chain kappa (Κ)/lambda (λ) ratio was 9.1. Renal biopsy showed a pronounced nodular mesangial appearance on light microscopy. Congo-red staining was negative. Immunofluorescence showed deposits composed of IgG along glomerular, tubular, and basement membranes, with negative staining for Κ and λ light chains, findings consistent with HCDD. The heavy chain subclass was not performed. Electron Microscopy revealed a powdery appearing deposition in the basement membrane.
Discussion
In elderly patients with nephrotic syndrome, diabetes and amyloidosis are common culprits. Our case supported this suspicion with a positive SPEP, IFE, and free light chain assay. However, while the kidney biopsy showed a nodular sclerosis pattern suggestive of amyloidosis, further analysis with staining and immunofluorescence revealed a rarer diagnosis: heavy chain deposition disease (HCDD) associated with a paraproteinemia. On review of the previously reported cases of HCDD, common clinical presentations include nephrotic syndrome, renal insufficiency, hematuria, and, in some cases, hypocomplementemia. Hematologic workup to assess for a plasma cell dyscrasia is ongoing.