Unmasking complex polymerization interferences in multiple myeloma diagnostics: A case study.

IF 2.9 3区医学 Q2 MEDICAL LABORATORY TECHNOLOGY

Clinica Chimica Acta Pub Date : 2025-10-18 DOI:10.1016/j.cca.2025.120675

Dan Han, Emily A Wolters, Folagbayi K Arowolo, Syed P Salam, Gia M Irudhayanathan, Damodara R Mendu

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引用次数: 0

Abstract

Monoclonal gammopathies, defined by the clonal overexpression of immunoglobulins, are typically diagnosed using serum protein electrophoresis (SPEP), immunofixation electrophoresis (IFE), and serum free light chain (FLC) assays. However, atypical immunoglobulin structures can introduce diagnostic challenges. We describe a case of IgG-lambda multiple myeloma presenting with a double M-spike on SPEP: one in the anodal gamma region and another in the cathodal gamma region, mimicking biclonal gammopathy. IFE showed biclonal-like lambda bands, and serum lambda FLC levels were markedly elevated by turbidimetric analysis. These discrepancies were resolved following treatment with dithiothreitol (DTT), which disrupted disulfide-linked lambda FLC polymers, confirming that polymerization was the source of the assay interferences. This case study highlights the critical role of DTT treatment in FLC lambda multiple myeloma that by breaking FLC lambda polymers into monomers, the overestimation by turbidimetric method of FLC lambda level can be dramatically improved.

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揭开复杂聚合干扰在多发性骨髓瘤诊断：一个案例研究。

单克隆伽玛病，由免疫球蛋白的克隆性过表达定义，通常使用血清蛋白电泳（SPEP）、免疫固定电泳（IFE）和血清游离轻链（FLC）检测来诊断。然而，非典型的免疫球蛋白结构会给诊断带来挑战。我们描述了一例IgG-lambda多发性骨髓瘤，在SPEP上表现为双m峰：一个在阳极伽马区，另一个在阴极伽马区，模拟双克隆伽玛病。IFE显示双克隆样lambda带，浊度分析血清lambda FLC水平明显升高。这些差异在用二硫苏糖醇（DTT）处理后得到了解决，DTT破坏了二硫化物连接的lambda FLC聚合物，证实了聚合是检测干扰的来源。本案例研究强调了DTT治疗在FLC lambda多发性骨髓瘤中的关键作用，通过将FLC lambda聚合物分解为单体，可以显着改善浊度法对FLC lambda水平的高估。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Clinica Chimica Acta 医学-医学实验技术

CiteScore

10.10

自引率

2.00%

发文量

1268

审稿时长

23 days

期刊介绍： The Official Journal of the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) Clinica Chimica Acta is a high-quality journal which publishes original Research Communications in the field of clinical chemistry and laboratory medicine, defined as the diagnostic application of chemistry, biochemistry, immunochemistry, biochemical aspects of hematology, toxicology, and molecular biology to the study of human disease in body fluids and cells. The objective of the journal is to publish novel information leading to a better understanding of biological mechanisms of human diseases, their prevention, diagnosis, and patient management. Reports of an applied clinical character are also welcome. Papers concerned with normal metabolic processes or with constituents of normal cells or body fluids, such as reports of experimental or clinical studies in animals, are only considered when they are clearly and directly relevant to human disease. Evaluation of commercial products have a low priority for publication, unless they are novel or represent a technological breakthrough. Studies dealing with effects of drugs and natural products and studies dealing with the redox status in various diseases are not within the journal''s scope. Development and evaluation of novel analytical methodologies where applicable to diagnostic clinical chemistry and laboratory medicine, including point-of-care testing, and topics on laboratory management and informatics will also be considered. Studies focused on emerging diagnostic technologies and (big) data analysis procedures including digitalization, mobile Health, and artificial Intelligence applied to Laboratory Medicine are also of interest.