Abstract: TH-PO963
Unusual Presentation of Cryoglobulin-Positive Fibrillary Glomerulonephritis
Session Information
- Glomerular Trainee Case Reports
November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Report
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Medeiros, Edward G., Brown Medicine, Providence, Rhode Island, United States
- Calabro-Kailukaitis, Nathan, Brown University, Providence, Rhode Island, United States
- Lynch, Matthew R., Brown Medicine, East Providence, Rhode Island, United States
Introduction
Fibrillary glomerulonephritis encompasses approximately 1% of adult native kidney biopsies. Although considered a predominantly idiopathic disease, up to 1/3 reveal a secondary cause such as monoclonal gammopathy, autoimmune disease or malignancy. In the two largest case series published to date, only 2 of 126 had positive serum cryoglobulins; it is unclear if these patients had concurrent HCV infection. A disease already associated with poor outcomes, little is known about those with Fibrillary GN and positive serum cryoglobulins.
Case Description
A 66 year-old female with history of longstanding diabetes mellitus, hypertension and stage III chronic kidney disease with serum creatinine 1.6mg/dL six months prior was admitted with abnormal labs including serum creatinine of 7mg/dL on routine testing. She denied localizing symptoms to explain worsening renal function. She was afebrile and initial blood pressure was 170/90mmHg. On physical exam, lungs were clear and there was no rash or edema. Repeat labs revealed serum creatinine 7.49mg/dL, BUN 57mg/dL, serum albumin 3.3g/dL and 7 grams of protein on 24hr collection. Urine sediment showed hematuria with dysmorphic RBCs and numerous WBCs. Further tests for HBV, HCV, HIV, ANA, ANCA, and anti-GBM were negative. Hypocomplementemia with undetectable C4 and normal C3 was present, along with elevated rheumatoid factor at 152 IU/mL; serum cryoglobulins were positive. SPEP was weakly positive for IgG lambda. Renal biopsy exhibited global glomerular sclerosis, and diffuse deposition of haphazardly arranged 15nm filaments within glomerular capillary walls and mesangial matrix on electron microscopy. Staining for DNAJB9 was positive. Despite treatment with Rituximab for 4 weeks, her disease progressed and required renal replacement therapy. Serum cryoglobulins remained positive after treatment.
Discussion
Fibrillary GN is a rare disease associated with poor renal outcomes and progression to ESRD. Only two previous cases of Fibrillary GN had positive serum cryoglobulins. There is little evidence to guide therapy in this disease, and even less is known about those with positive serum cryoglobulins. Efforts to identify secondary causes in such patients should include viral illness, malignancy and autoimmune disease. Further investigations to evaluate more effective therapeutic options are needed.