IgA kappa/IgA lambda 重/轻链评估在 IgA 骨髓瘤患者管理中的应用。

IgA kappa/IgA lambda heavy/light chain assessment in the management of patients with IgA myeloma.

机构信息

Clinical Hematology Department, Huriez Hospital, Regional University Medical Center, Lille, France.

出版信息

Cancer. 2014 Dec 15;120(24):3952-7. doi: 10.1002/cncr.28946. Epub 2014 Aug 12.

DOI:10.1002/cncr.28946

PMID:25116271

Abstract

BACKGROUND

Accurate quantification of immunoglobulin A (IgA) monoclonal immunoglobulins by serum protein electrophoresis (SPEP) can be difficult and can impact the assessment of response among patients with multiple myeloma (MM). Therefore, there is a need to identify new assays that better reflect disease burden and response to treatment, and correlate with patient outcome. IgA Hevylite (HLC) measures IgA kappa and IgA lambda separately and provides precise quantitative measurements of the monoclonal IgA expression and polyclonal-isotype matched suppression. In the current study, the authors assessed the usefulness of these assays in the diagnosis of IgA MM and sought to comment on the prognostic value of the assays.

METHODS

A study of 157 patients with IgA MM for whom diagnostic samples were available was performed. HLC measurements were performed on a nephelometer and the results were compared with those of electrophoresis.

RESULTS

All presentation sera (100 IgA kappa specimens and 57 IgA lambda specimens) were found to have abnormal IgA HLC ratios (IgA kappa median ratio: 336.2 [range, 8.2-7353] and IgA lambda ratio: 0.011 [range, 0.0003-0.45]). In comparison, SPEP bands were quantifiable in only 105 of 157 samples (67%) (median, 28.5 g/L [range, 2.2 g/L-98 g/L]). Of the total of 157 patients, 12 patients (8%) presented with oligosecretory myeloma (<10 g/L; including 4 patients with nonquantifiable SPEP bands). HLC uniquely allows for the measurement of isotype paired suppression, which was found to be associated with shortened overall survival in the current study.

CONCLUSIONS

In the current study, IgA HLC ratios were found to be abnormal in all patients and the assay was able to produce quantifiable results in more MM sera than either SPEP or total IgA, potentially representing a solution to the issue of comigration and oligosecretory MM. These preliminary data require confirmation in larger prospective trials to validate the usefulness of IgA HLC.

摘要

背景

通过血清蛋白电泳（SPEP）准确量化免疫球蛋白 A（IgA）单克隆免疫球蛋白可能较为困难，并且会影响多发性骨髓瘤（MM）患者的反应评估。因此，需要识别新的检测方法，这些方法更好地反映疾病负担和对治疗的反应，并与患者的预后相关。IgA Hevylite（HLC）分别测量 IgA κ 和 IgA λ，并提供对单克隆 IgA 表达和多克隆同型匹配抑制的精确定量测量。在本研究中，作者评估了这些检测方法在 IgA MM 诊断中的作用，并试图对这些检测方法的预后价值进行评论。

方法

对 157 例有 IgA MM 诊断样本的患者进行了研究。在比浊仪上进行 HLC 测量，并将结果与电泳结果进行比较。

结果

所有表现血清（100 例 IgA κ 标本和 57 例 IgA λ 标本）的 IgA HLC 比值均异常（IgA κ 中位数比值：336.2 [范围，8.2-7353]和 IgA λ 比值：0.011 [范围，0.0003-0.45]）。相比之下，只有 157 例样本中的 105 例（67%）可定量 SPEP 条带（中位数，28.5 g/L [范围，2.2 g/L-98 g/L]）。在总共 157 例患者中，有 12 例（8%）患者表现为寡分泌性骨髓瘤（<10 g/L；包括 4 例 SPEP 条带不可定量的患者）。HLC 可以独特地测量同型配对抑制，本研究发现这与总生存期缩短相关。