Crystalglobulin-associated nephropathy presenting as MGRS in a case of monoclonal B-cell lymphocytosis: a case report

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Springer Science and Business Media LLC
<jats:title>Abstract</jats:title><jats:sec> <jats:title>Background</jats:title> <jats:p>Crystalglobulin-associated nephropathy (CAN), a rare subtype of monoclonal gammopathy, usually associated with multiple myeloma and occasionally monoclonal gammopathy of uncertain significance (MGUS), is characterized by occluding monoclonal pseudothrombi within renal glomerular capillaries and/or interstitial arterioles. Ultrastructurally, these pseudothrombi are unique for having a crystalline substructure. We describe a case of an adult patient with monoclonal B-cell lymphocytosis (MBL) and acute renal failure whose kidney biopsy revealed a rare diagnosis of CAN.</jats:p> </jats:sec><jats:sec> <jats:title>Case presentation</jats:title> <jats:p>A 63-year old male presented with a 2-month history of edema, arthralgia and malaise. He had acute kidney injury with hematoproteinuria on urine analysis. Serum and urine protein electrophoresis were both negative. A renal biopsy however revealed features of CAN. Organomegaly, bone pain and lymphadenopathy were absent. A repeat serum electrophoresis was positive for IgA kappa and a free light chain assay showed elevated free kappa light chains. Flow cytometry done subsequently revealed a diagnosis of MBL, chronic lymphocytic leukemia (CLL) type.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusion</jats:title> <jats:p>CAN in association with MBL/CLL has not been previously described in literature, and our case highlights yet another instance of monoclonal gammopathy of renal significance (MGRS) where a small B-cell clone resulted in extensive renal pathology without systemic manifestations.</jats:p> </jats:sec>
Rajib K. Gupta, Lois J. Arend, Anupama BK, et al. (2020-5-18). "Crystalglobulin-associated nephropathy presenting as MGRS in a case of monoclonal B-cell lymphocytosis: a case report." BMC Nephrology. 21 (1). 10.1186/s12882-020-01818-5.