An up-conversion fluorescence lateral-flow immunoassay for rapid detection of Daratumumab in serum protein electrophoresis clinical samples

Yajing Liu; Yanru Tao; Priscilla S-W Yeung; Mengyan Lu; Jing Liu; Fang Yu; Run-Zhang Shi; Ruben Yiqi Luo

doi:10.1016/j.cca.2024.119677

An up-conversion fluorescence lateral-flow immunoassay for rapid detection of Daratumumab in serum protein electrophoresis clinical samples

Clin Chim Acta. 2024 Apr 16:559:119677. doi: 10.1016/j.cca.2024.119677. Online ahead of print.

Authors

Yajing Liu¹, Yanru Tao², Priscilla S-W Yeung³, Mengyan Lu², Jing Liu², Fang Yu², Run-Zhang Shi³, Ruben Yiqi Luo⁴

Affiliations

¹ Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA.
² Polariton Life Technologies, Suzhou, Jiangsu, China.
³ Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Clinical Laboratories, Stanford Health Care, Palo Alto, CA, USA.
⁴ Department of Pathology, School of Medicine, Stanford University, Stanford, CA, USA; Clinical Laboratories, Stanford Health Care, Palo Alto, CA, USA. Electronic address: rubenluo@stanford.edu.

PMID: 38636694
DOI: 10.1016/j.cca.2024.119677

Abstract

Background: Daratumumab (DARA) is a commonly used monoclonal antibody (mAb) drug for the treatment of multiple myeloma (MM). Its appearance as a visible abnormal band in the γ-region of a serum protein electrophoresis (SPEP) gel may interfere with the SPEP result interpretation. With the advantages of portability and rapid testing capabilities, up-conversion fluorescence lateral-flow immunoassay (LFA) can be an ideal solution to detect DARA interference.

Methods: An up-conversion fluorescence LFA strip was designed and constructed to perform semi-quantitative DARA testing in clinical samples. The LFA strip test was evaluated for limit of detection (LOD), dynamic range, and analytical interference.

Results: To demonstrate the clinical utility of the LFA strip, 43 SPEP-positive patient serum samples were tested for the presence of DARA, and the results exactly matched the DARA usage history in patient medical records.

Conclusions: The performance of the up-conversion fluorescence LFA strip meets the purpose of clarifying DARA interference in SPEP results. It may be used as an independent and objective confirmation of the presence of DARA in clinical samples. The LFA strip offers a cost-effective rapid on-site test to check for DARA interference alongside standard SPEP equipment, which significantly improves the interpretation of ambiguous SPEP results involving DARA, and does not intervene the current SPEP workflow in clinical laboratory practice.

Keywords: Daratumumab; Lateral-flow immunoassay; Serum protein electrophoresis; Up-conversion fluorescence.