Analytical interference in immunoassays: clinical impact and mitigation strategies

Abstract

Immunoassays are a highly useful and essential laboratory methodology in modern diagnostics for quantifying hormones, tumor markers, cardiac biomarkers, and infectious agents. However, they can be subject to analytical interferences of both endogenous and exogenous origin, leading to falsely elevated or decreased results and impacting patient diagnosis. The objective of this study is to analyze interferences in immunoassay analysis, their impact on the interpretation of results, and the available mitigation strategies. Therefore, a systematic review was conducted based on the available literature, following the PRISMA 2020 guidelines. The search was performed in various data sources, including studies published between 2021 and 2026 on interferences in immunoassays. Data were extracted on the type of interference, affected analyte, analytical platform, magnitude of error, clinical consequence, and mitigation strategy used. Of the 380 records identified, 31 studies were included in the results. The main interfering factors were heterophile antibodies, autoantibodies, macroforms, biotin, and drugs. The analytes with the greatest interference included parathyroid hormone, thyroid-stimulating hormone, prolactin, and troponin, among others, impacting endocrinology, cardiology, oncology, infectious diseases, and reproductive medicine. In conclusion, analytical interferences in immunoassays are a significant cause of diagnostic error; therefore, their detection requires correlation between clinical and laboratory findings, as well as the application of dilutions, blocking agents, polyethylene glycol, biotic suspension, and alternative confirmatory methods.