Autologous stem cell transplantation as a treatment modality for type 1 cryoglobulinemia in monoclonal gammopathy of renal significance.

Abstract

e19500 Background: Type I cryoglobulinemia (CRYO) can be driven by disorders such as plasma cell dyscrasias. Monoclonal gammopathy of renal significance (MGRS) represents a group of kidney disorders characterized by the presence of a paraprotein; though not fitting the criteria for a hematologic malignancy. There exists no standard approach to manage these patients. Our patient is a 56-year-old man who was initially evaluated for edema. Workup revealed worsening renal function and proteinuria (Figure 1). Renal biopsy revealed abundant cryofibrinogen deposits and cryoglobulinemic glomerulonephritis with membranoproliferative pattern. Bloodwork showed type I (IgG Kappa) CRYO. Bone marrow evaluation revealed 7% clonal plasma cells. Further evaluation did not confirm a diagnosis of myeloma. Methods: Treatment was initiated with bortezomib, cyclophosphamide and dexamethasone. After 3 cycles of therapy the patient had normalization of his creatinine and marked improvement in edema. Peripheral blood stem cells were mobilized following the administration of high-dose cyclophosphamide (2gm/m2) plus filgrastim. He was subsequently conditioned for transplantation with high-dose melphalan (200mg/m2; HDM) followed by autologous stem cell rescue. He tolerated the procedure well without any unexpected toxicities; achieving prompt hematologic recovery Results: Evaluations post transplant revealed resolution of any circulating cryoglobulins and reduction in proteinuria. At 1 year post transplant, the patient has returned to his premorbid condition. Conclusions: Type 1 CRYO associated MGRS represents a complicated disorder for which there is no consensus treatment approach. As this process may be driven by clonal plasma cells, classical anti-myeloma therapy may provide a strategy for management. Given the typical low plasma cell burden in these patients, HDM has the potential to offer deep and durable remissions. Prospective studies are needed to validate this approach. [Table: see text]