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Abstract: SA-PO225

Digital Necrosis: Presenting Feature of Type 1 Cryocrystalglobulinemia

Session Information

Category: Onconephrology

  • 1700 Onconephrology


  • Dhillon, Chaudhry Hamood Ahmed, Rush University Medical Center, Chicago, Illinois, United States
  • Rodby, Roger A., Rush University Medical Center, Chicago, Illinois, United States

Type I cryoglobulinemia involves cryoprecipitable monoclonal Igs associated with multiple myeloma, Waldenstrom macroglobulinemia, or chronic lymphocytic leukemia (CLL). Some cryoglobulins can “crystalize”, causing vaso-occlusive gangrene in addition to a glomerulopathy with a specific pattern of injury.

Case Description

A 64-y/o man presented with a purpuric ankle rash, and bluish discoloration of his fingers and toes (Fig. 1). Labs revealed AKI with pancytopenia, microscopic hematuria, and a urine Alb/Creat ratio of 500 mg/g. He had negative or normal testing for hepatitis B and C, HIV, Protein C and S activity, ANA, AntiDS-DNA, anti-scleroderma and anti-centromere antibodies, C3 and C4 levels, RF, antiphospholipid Abs, and ANCA. Serum immunofixation showed a monoclonal IgG kappa paraprotein. Cryoglobulin (CG) testing was negative X2. A renal bx demonstrated an MPGN pattern of injury with vascular thrombi, both with IgG kappa restricted staining on immunofluorescence. Electron micrographs revealed subendothelial and intraluminal electron-dense deposits with crystalline lattice-like substructures c/w cryocrystalglobulinemia (Fig. 1). Repeat CG testing showed a cryocrit of 5% that was also IgG kappa restricted on immunofixation. He received plasmapheresis and steroids. He developed AKI and required HD for a week after which his AKI resolved. He was eventually diagnosed with CLL and received clone-directed therapy with acalabrutinib. His digits required amputation, but his kidney tests normalized.


The majority of CGs are “mixed” Type 2 & 3 associated with infections and autoimmune dz. Type 1 cryoglobulinemia is from a paraprotein produced by a plasma cell dyscrasia or a lymphoproliferative disorder. When the CGs form a crystalline substructure, they can cause vascular occlusion (his digits). Fortunately, his renal disease remitted. His presentation of digital ischemia suggested vasculitis, catastrophic anti-phospholipid syndrome, and cryoglobulinemia. The dx in this case ultimately depended on a renal biopsy and demonstrating the CG, a test that requires proper delivery and measurement.

Fig. 1.