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Abstract: PO1503

Monoclonal Gammopathy in a Patient with Lupus Nephritis: A Case Report

Session Information

Category: Glomerular Diseases

  • 1202 Glomerular Diseases: Immunology and Inflammation


  • Albasha, Waseem, Banner University Medical Center Tuscon, Tucson, Arizona, United States
  • Ashoka, Ankita, Banner University Medical Center Tuscon, Tucson, Arizona, United States
  • Bracamonte, Erika R., Banner University Medical Center Tuscon, Tucson, Arizona, United States
  • Thajudeen, Bijin, Banner University Medical Center Tuscon, Tucson, Arizona, United States

Monoclonal gammopathy of undetermined significance (MGUS) has known associations with many disorders, including inflammatory and connective tissue disorders. Systemic lupus erythematosus (SLE) is not traditionally considered to have an association with MGUS. However, a few studies and case reports have emerged that have suggested an association between MGUS and SLE. We describe herein a case of a patient who was newly diagnosed with lupus nephritis but also was found to MGUS.

Case Description

A 53-year-old gentleman with a history of hypertension presented to the hospital with blurry vision and bilateral lower extremity rash. He was found to have acute kidney injury (creatinine 1.67 mg/dl), microscopic hematuria (21-50 RBCs/HPF), proteinuria (24 hour urine protein 1,148 mg/day), and low complements (C3 50 mg/dl, C4 7 mg/dl, and CH50 13 U/ml). Kidney biopsy confirmed focal proliferative glomerulonephritis with full-house immunofluorescence staining and three cellular crescents, consistent with class III lupus nephritis. Interestingly his ANA and double-stranded DNA serologies were negative. Serum immunofixation was positive for an IgM lambda type monoclonal gammopathy. Bone marrow biopsy showed 2.1% plasma cells. Hematology/oncology was consulted and diagnosed him with MGUS. Incidentally, he was found to have type I cryoglobulinemia as well, with cryoglobulin immunofixation positive for IgM kappa type. The patient was given high-dose steroids, transitioned to prednisone, and started on mycophenolate mofetil. A t two months of treatment creatinine was 1.1 mg/d, proteinuria improved to 300 mg/gm creatinine.


The pathophysiologic mechanism that has been suggested for the development of MGUS in patients with lupus is dysregulation in B cell populations and immunoglobulin production. Lupus is known to produce hyperactivity in B cells and a polyclonal increase in gamma globulins. It is likely that in some patients with lupus, B cell regulation becomes impaired in a way that allows a clonal, but not necessarily neoplastic, an expansion that results in increased production of paraproteins, leading to MGUS. This case adds to the literature showing that there indeed may be an association between MGUS and lupus.