Interference of therapeutic monoclonal antibodies with electrophoresis and immunofixation of serum proteins: state of knowledge and systematic review.

Abstract

Introduction: The increasing use of therapeutic monoclonal antibodies (t-mAbs) has improved cancer and autoimmune disorder treatment. These therapeutics can interfere with serum protein electrophoresis (SPEP) and immunofixation (IF), potentially leading to the appearance of monoclonal bands that may be misinterpreted as monoclonal gammopathies. Identifying the migration patterns and detection thresholds of t-mAbs is crucial to avoid misinterpretation in clinical laboratories.

Content: A systematic review following PRISMA guidelines was conducted using Pubmed and ScienceDirect databases, with algorithm-based searches and double-blind article selection. Data on the matrix used, separation methods and type of interference were collected into an extraction table.

Summary: A total of 30 articles were included and 30 t-mAbs were described. 11 t-mAbs migrated at the end of the gamma region, 12 in the mid-gamma region, 5 in the early gamma region, one in the beta-2 globulin region and one in the alpha-2 globulin region. Most t-mAbs were detectable by SPEP and IF at concentrations above 100 mg/L.

Outlook: Caution is needed when a new peak appears on SPEP, as it may be mistaken for a monoclonal spike leading to misdiagnosis. Therefore, understanding the migration profiles of these t-mAbs is essential. Different methods are available to remove t-mAbs interference and could be used in daily practice.