Abstract: SA-PO234
Crystalglobulinemia: A Rare and Complex Clinical Entity
Session Information
- Trainee Case Reports - V
October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Trainee Case Reports
- 1203 Glomerular Diseases: Clinical, Outcomes, and Trials
Authors
- Zhang, Zi R., Rush University Medical Center, Chicago, Illinois, United States
- Ruddock-Walker, Sara, Rush University Medical Center, Chicago, Illinois, United States
- Baxi, Pravir V., Rush University Medical Center, Chicago, Illinois, United States
- Gashti, Casey N., Rush University Medical Center, Chicago, Illinois, United States
- Rodby, Roger A., Rush University Medical Center, Chicago, Illinois, United States
Introduction
Crystalglobulinemia (CryG) is a rare Monoclonal Gammopathy of Renal Significance (MGRS) that results in a crystalline appearing precipitation of paraproteins in the glomeruli. These paraproteins are unique in that they are not cryoprecipitable, but form immune aggregates that appear crystalline on Electron Microscopy (EM). Clinical manifestations include purpura, arthropathy and AKI. We present a case of crystalglobulin-induced AKI in a pt with a monoclonal IgA lambda paraproteinemia. Early recognition and treatment led to resolution of her AKI.
Case Description
A 44-y/o F p/w arthralgias, HTN and edema. Labs: Cr of 1.4 mg/dL and Alb 3.7 g/dL. UA: +RBCs with a urine alb/Cr ratio of 6.3 g/g. Workup: ANA, ANCA, C3, C4, and hepatitis all neg or nml. Monoclonal IgA lambda was seen on serum and urine immunofixation. Serum k/l ratio was 0.76. A renal biopsy demonstrated on Light Microscopy: Lobular glomeruli with the majority showing intracapillary eosinophilic thrombi that stained 3+ for IgA and lambda (kappa-). EM: the thrombi were composed of crystalline structures with an organized substructure of parallel linear arrays (Fig 1). No evidence of cast nephropathy. Serum cryoglobulins were repeatedly negative. She developed AKI (Cr of 4.2) and was started on plasmapheresis (TPE) and steroids. A bone marrow biopsy showed a plasma cell neoplasm in 7% of cells with lambda predominance by flow cytometry. Therapy with bortezomib and cyclophosphamide was administered. A bone survey showed no lytic lesions. Three weeks following initiation of therapy, her Cr improved to 1.0.
Discussion
CryG is rare and illustrates the complexity of the MGRS spectrum. Diagnosis requires histologic evidence of characteristic crystalglobulin deposition within the vasculature in the absence of circulating cryoglobulins. This case emphasizes the importance of specific histologic diagnosis to guide treatment for pts with MGRS. In this case, TPE and steroids served as a bridge until directed chemotherapy was started.
Renal Biopsy