Effect of long-term frozen storage on stability of kappa free light chain index.

IF 3.8 2区医学 Q1 MEDICAL LABORATORY TECHNOLOGY

Clinical chemistry and laboratory medicine Pub Date : 2025-05-08 DOI:10.1515/cclm-2025-0125

Martin Schmidauer, Klaus Berek, Gabriel Bsteh, Michael Auer, Robert Barket, Franziska Di Pauli, Michaela Hassler, Dejan Milosajevic, Anne Zinganell, Janette Walde, Florian Deisenhammer, Harald Hegen

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引用次数: 0

Abstract

Objectives: To investigate whether frozen storage duration influences κ-FLC index.

Methods: CSF and serum samples of patients with multiple sclerosis collected for routine diagnostic purposes had been stored at -20 °C. κ-FLC and albumin concentrations were measured at two different timepoints, i.e. before and after storage. The κ-FLC index was calculated as (CSF κ-FLC/serum κ-FLC)/(CSF albumin/serum albumin).

Results: A total of 70 patients were included showing median CSF κ-FLC concentration of 0.25 (25th-75th percentile: 0.12-0.43) mg/dL, serum κ-FLC concentration of 1.05 (0.86-1.34) mg/dL, CSF albumin concentration of 17.7 (14.6-26.1) mg/dL and serum albumin concentration of 4230 (3898-4488) mg/dL. The κ-FLC index was 44 (25-108). With increasing frozen storage duration, the absolute concentrations of CSF κ-FLC, serum κ-FLC, CSF albumin and serum albumin decreased, while the κ-FLC index remained stable. The observed changes in absolute concentrations evened out by using CSF/serum ratios of κ-FLC and albumin when calculating the κ-FLC index.

Conclusions: Frozen storage at -20 °C has no relevant impact on κ-FLC index.

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长期冷冻贮藏对卡帕游离轻链指数稳定性的影响。

目的：探讨冷冻保存时间对κ-FLC指数的影响。方法：采集用于常规诊断的多发性硬化症患者脑脊液和血清标本，保存于-20 °C。测定贮藏前后两个不同时间点的κ-FLC和白蛋白浓度。κ-FLC指数计算为（CSF κ-FLC/血清κ-FLC）/（CSF白蛋白/血清白蛋白）。结果：共纳入70例患者，脑脊液κ-FLC中位浓度为0.25（25 -75百分位：0.12-0.43） mg/dL，血清κ-FLC浓度为1.05（0.86-1.34） mg/dL，脑脊液白蛋白浓度为17.7（14.6-26.1） mg/dL，血清白蛋白浓度为4230（3898-4488） mg/dL。κ-FLC指数为44（25-108）。随着冷冻时间的延长，脑脊液κ-FLC、血清κ-FLC、脑脊液白蛋白和血清白蛋白的绝对浓度降低，而κ-FLC指数保持稳定。在计算κ-FLC指数时，使用CSF/血清中κ-FLC和白蛋白的比值来平衡所观察到的绝对浓度变化。结论：-20 °C冷冻保存对κ-FLC指数无相关影响。

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

Clinical chemistry and laboratory medicine 医学-医学实验技术

CiteScore

11.30

自引率

16.20%

发文量

306

审稿时长

3 months

期刊介绍： Clinical Chemistry and Laboratory Medicine (CCLM) publishes articles on novel teaching and training methods applicable to laboratory medicine. CCLM welcomes contributions on the progress in fundamental and applied research and cutting-edge clinical laboratory medicine. It is one of the leading journals in the field, with an impact factor over 3. CCLM is issued monthly, and it is published in print and electronically. CCLM is the official journal of the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) and publishes regularly EFLM recommendations and news. CCLM is the official journal of the National Societies from Austria (ÖGLMKC); Belgium (RBSLM); Germany (DGKL); Hungary (MLDT); Ireland (ACBI); Italy (SIBioC); Portugal (SPML); and Slovenia (SZKK); and it is affiliated to AACB (Australia) and SFBC (France). Topics: - clinical biochemistry - clinical genomics and molecular biology - clinical haematology and coagulation - clinical immunology and autoimmunity - clinical microbiology - drug monitoring and analysis - evaluation of diagnostic biomarkers - disease-oriented topics (cardiovascular disease, cancer diagnostics, diabetes) - new reagents, instrumentation and technologies - new methodologies - reference materials and methods - reference values and decision limits - quality and safety in laboratory medicine - translational laboratory medicine - clinical metrology Follow @cclm_degruyter on Twitter!