Optimizing the Utility of Serum Protein Electrophoresis

Abstract

Hollie Sheffield, Haekyung Jeon-Slaughter, Nivan Chowattukunnel, Waqas Haque, Mir Lim, Evelyn Shen and Yu-Min Shen

Introduction: Serum protein electrophoresis (SPEP) is often obtained to look for monoclonal gammopathy when evaluating nonspecific clinical findings. Currently optimal utilization of SPEP is not well defined. This study was conducted to identify patient characteristics or laboratory data as appropriate indications for ordering SPEP.

Material and Methods: A retrospective review of 406 patients referred for abnormal SPEPs from 2012 to 2019 was performed to identify characteristics that predict for development of lymphoplasmacytic malignancy. Indications for ordering the SPEP, serum calcium, serum creatinine, hemoglobin, and presence of bone lesions were recorded. Specific monoclonal (M) component types were also analyzed.

Results: Of those patients, 27 were found to have a lymphoplasmacytic malignancy (LPM). The most documented reasons for SPEP testing were renal dysfunction, increased globulin fraction, anemia, and neuropathy. Patients with at least one CRAB criteria (hypercalcemia, renal dysfunction, anemia, or bone lesion) had a significantly increased risk of developing a LPM. In evaluating the M-component subtype, patients with IgA M-components had a significantly higher chance of progression to a LPM when compared to IgG (37% vs 8.2%). An M-component of >1.5 g/dL was associated with significantly increased risk for developing a LPM (Odds Ratio 45.8; 95% Confidence Interval, 10.7-195.8).

Conclusion: We conclude that SPEP should be ordered for patients with CRAB criteria or otherwise unexplained neurological or dermatological disorders. Once an SPEP has been ordered and found to be abnormal, patient-specific characteristics such as presence of CRAB criteria and IgA M-component can be used to guide follow-up and need for a hematology referral.

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