Jump to Main Content


A 78-Year-Old Man with Anasarca and Chronic Kidney Disease

Hematopoiesis Case StudiesA 78-year-old man with a medical history of gastroesophageal reflux disease (GERD) and essential hypertension presented to his primary care physician for evaluation of lower extremity edema and weight gain of one month’s duration. His complete blood count showed a white blood count of 10.8 × 10/µL, hemoglobin of 12 g/dL, and platelets of 249 × 109/µL. His basic metabolic panel (BMP) showed creatinine of 2.37 mg/dL (baseline creatinine, 1.02 mg/dL), albumin of 1.7 g/dL, and normal BMP otherwise. A serum protein electrophoresis demonstrated a monoclonal protein present in the gamma region, with a concentration of 1.8 g/dL. Immunofixation demonstrated an IgM κ monoclonal protein with elevated concentration of 2,917 mg/dL. A skeletal survey showed no lytic lesions. On physical exam, he was noted to have 7 kg weight gain and non-pitting edema of lower extremities extending to thighs.

A kidney biopsy was obtained, and pathology demonstrated a “fluffy,” finely granular electron–dense material in the periphery of glomerular basement and focally along the subendothelial aspect with widespread foot effacement. Immunofluorescence demonstrated a κ-restricted staining consistent with IgM κ monoclonal gammopathy.

He underwent a bone marrow biopsy, which showed normocellular bone marrow with trilineage hematopoiesis and no increase in plasma cells. Fluorescence in situ hybridization (FISH) and karyotype were normal.


Table. Differentiation between MGUS, MGRS, and MM.

Clonal burden
  • Low
  • Monoclonal protein spike <3 g/dL
  • Plasma cells <10% of bone marrow
  • Low
  • Monoclonal protein spike <3 g/dL
  • Plasma cells <10% of bone marrow
  • High
  • Monoclonal protein spike >3 g/dL
  • Plasma cells >10% of bone marrow
Organ damage No Yes  Yes (CRAB)
Kidney disease No (or unrelated) Yes  Yes (common 50%)
Kidney biopsy No  Yes (biopsy and immunofluorescence studies to identify the monotypic immunoglobulin deposits) No (most cases do not need a kidney biopsy)
Treatment   No (only surveillance) Yes Yes 

As summarized in “Diagnosis of monoclonal gammopathy of renal significance” by Bridoux et al, 2015.

  1. Khera A, Panitsas F, Djebbari F, et al. Long term outcomes in monoclonal gammopathy of renal significance. Br J Haematol. 2019;186:706-716.
  2. Bridoux F, Leung N, Hutchison CA, et al. Diagnosis of monoclonal gammopathy of renal significance. Kidney Int. 2015;87:698-711.
  3. Fermand JP, Bridoux F, Kyle RA, et al. How I treat monoclonal gammopathy of renal significance (MGRS). Blood. 2013;122:3583-3590.