Fig. 1. Serum immunofixation electrophoresis.

Arrow denotes application point. Lanes labeled according to the antiserum applied (G, anti-IgG; D, anti-IgD; E, anti-IgE; K, total kappa; FKS, free kappa using antisera manufactured by Sebia; FKH, free kappa using antisera manufactured by Helena; L, total lambda; FLS, free lambda using antisera manufactured by Sebia; FLH, free lambda using antisera manufactured by Helena); ×2 denotes that the sample was run using 50 μL of the sample diluted in 50 μL of water.

Case Description

A 68-year-old woman with a bone marrow biopsy positive for kappa monotypic plasma cells (approximately 90% total) and flow cytometric analysis showing kappa-restricted plasma cells (approximately 17% of total) had unremarkable serum and urine immunofixation electrophoresis (Fig. 1). Her serum protein electrophoresis was remarkable for hypogammaglobulinemia [IgG 563 mg/dL (reference interval 600–1600 mg/dL), IgA 73 mg/dL (40–375 mg/dL), IgM 17 mg/dL (30–190 mg/dL)]. Serum free light chain (sFLC) results were consistent with the bone marrow biopsy: kappa-sFLC 668 mg/L (3.3–19.4 mg/dL); lambda-sFLC 6.0 mg/dL (5.7–23.3 mg/dL). All serum results were repeated with a second sample.


  1. What type of plasma cell dyscrasia is associated with these results?
  2. How should this patient be monitored?
Read the article here for the answers.