Caillon Hélène, Avet-Loiseau Hervé, Attal Michel, Moreau Philippe, Decaux Olivier, Dejoie Thomas
Department of Biochemistry, University Hospital of Nantes, Nantes, France.
Unity of Genomics in Myeloma, University Hospital of Toulouse, Toulouse, France.
Clin Lymphoma Myeloma Leuk. 2019 May;19(5):e228-e237. doi: 10.1016/j.clml.2019.01.007. Epub 2019 Jan 29.
Serum free light chain (FLC) measurement has become an important marker for the management of multiple myeloma (MM). However, several analytical challenges remain unresolved. We compared the clinical performances of the Sebia FLC assay in MM to the Freelite assay.
A total of 177 patients from the IFM DFCI 2009 trial were enrolled onto this study, with a total of 368 samples analyzed. At baseline, concordance of the involved to noninvolved FLC ratio (iFLC/niFLC) was evaluated. During therapy, comparison of the disease response assessments according to International Myeloma Working Group criteria was performed.
Compared to Freelite, the Sebia FLC assay demonstrated lower results, with a proportional bias with increased values. We demonstrated that the Sebia equivalent of the iFLC/niFLC ratio of 100 was 16. During follow-up, agreement in response assessment was moderate (for light chains MM) to good (for intact immunoglobulin MM). In the context of relapse, the concordance was moderate, but longitudinal follow-up showed a similar kinetics.
The Sebia FLC assay provides inequivalent absolute results from the Freelite assay. Despite lower absolute FLC values, the kinetics of response and relapse is exactly the same. As with other FLC assays available, follow-up of MM with the same method is advisable.
血清游离轻链（FLC）检测已成为多发性骨髓瘤（MM）管理的一项重要标志物。然而，一些分析挑战仍未得到解决。我们将塞比亚FLC检测在MM中的临床性能与弗里莱特检测进行了比较。
IFM DFCI 2009试验中的177例患者被纳入本研究，共分析了368份样本。在基线时，评估受累与未受累FLC比值（iFLC/niFLC）的一致性。在治疗期间，根据国际骨髓瘤工作组标准对疾病反应评估进行比较。
与弗里莱特检测相比，塞比亚FLC检测结果较低，且随着数值增加存在比例偏差。我们证明塞比亚检测中iFLC/niFLC比值为100时，其等效值为16。在随访期间，反应评估的一致性在轻链型MM中为中等（程度），在完整免疫球蛋白型MM中为良好。在复发情况下，一致性为中等，但纵向随访显示出相似的动力学变化。
塞比亚FLC检测提供的绝对结果与弗里莱特检测不等效。尽管绝对FLC值较低，但反应和复发的动力学变化完全相同。与其他可用的FLC检测一样，建议采用相同方法对MM进行随访。
