Abstract: FR-PO0795
Cryocrystalglobulinemia or ANCA-Associated Vasculitis: The Importance of Repeat Kidney Biopsy
Session Information
- Glomerular Diseases: ANCA Vasculitis, Anti-GBM Disease, and Crescentic GN
October 23, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Njaravelil, Kristi A., The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Jennette, John Charles, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
- Jain, Koyal, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
Introduction
Cryocrystalglobulinemia is a rare variant of cryoglobulinemia that is often associated with monoclonal gammopathy and characterized by crystalloid deposits within vessels. It is associated with IgG dominant staining on immunofluorescence. Antineutrophil cytoplasmic antibody (ANCA) associated glomerulonephritis presents as a pauci-immune crescentic pattern and is histologically distinct. Overlapping clinical and serologic features, however, can obscure the diagnosis. This case shows how a repeat kidney biopsy can significantly alter diagnosis and management in a patient with an unclear diagnosis on initial biopsy.
Case Description
A 26-year-old male with obesity and hidradenitis suppurativa initially presented with proteinuria, hematuria, and creatinine of 1.5 mg/dL. Serologies were remarkable for dual-positive ANCA (PR3 2.5 U and MPO 2.9 U; normal <0.9 U), positive ANA, normal complement levels, and IgM lambda monoclonal protein on immunofixation with normal light chain ratio. Renal biopsy at the time showed focal sclerosis, IgG-dominant immune complex glomerulonephritis with organoid deposits, raising concern for cryocrystalglobulinemic glomerulopathy. There was no evidence of infectious etiology or drug use. Immunosuppression was deferred pending evaluation for a potential underlying myeloproliferative disorder; however, the patient did not follow up. Over 1 year, the patient’s creatinine rose to 3.5–4.2 mg/dL with 5 g of proteinuria. Symptoms included fatigue, edema, and dyspnea. Repeat kidney biopsy revealed pauci-immune crescentic and sclerosing glomerulonephritis with PR3-ANCA titers of 101.9 U/mL (normal <21 U/mL), without monoclonal restriction. He was treated with pulse steroids and rituximab with clinical improvement and follow-up creatinine of 2.9 mg/dL 2 months later.
Discussion
This case illustrates the importance of repeating renal biopsy in the setting of clinical progression, particularly when the initial diagnosis does not fully align with the clinical picture and serologic workup. While kidney biopsies remain the gold standard for diagnosis and prognosis of glomerular disease, limitations such as indeterminate findings, overlapping features, and sampling variability can limit interpretation and reduce accuracy. Repeat evaluation can identify evolving pathology and ultimately affect management and prognosis.