单克隆丙种球蛋白病诊断时的尿液分析：确定临界值。

Urine analysis in monoclonal gammopathies at diagnosis: settling cut-off values.

作者信息

Vidal-Pla Mònica, Nuez-Zaragoza Elisa, Bhambi Indira, Aguadero Vicente

机构信息

Biochemistry Department, Clinical Laboratory, Parc Taulí University Hospital, Institut d'Investigació i Innovació Parc Taulí I3PT, Universitat Autònoma de Barcelona, Sabadell, Barcelona, Spain.

Laboratory Department, Sant Joan Despí Moisès Broggi Hospital, CLILAB Diagnòstics, Barcelona, Spain.

出版信息

Adv Lab Med. 2024 Sep 23;5(4):439-442. doi: 10.1515/almed-2024-0045. eCollection 2024 Dec.

DOI:10.1515/almed-2024-0045

PMID:39713529

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11661531/

Abstract

OBJECTIVES

Laboratory testing has an extensive role in the diagnosis of monoclonal gammopathies. Since the last updates of the International Myeloma Working Group (IMWG) guidelines for the diagnosis of monoclonal gammopathies, debate has arisen as to whether urine analysis remains relevant for the diagnosis of these entities.

METHODS

We carried out a retrospective study with data from 132 patients with a newly diagnosed serum M-protein. Patients were divided into two groups depending on the presence of M-protein in urine and different variables were recorded and statistically compared between groups.

RESULTS

The aim of the study was to find a serum M-protein cut-off value under which urine analysis could be avoided in the first laboratory diagnosis. The results show that when the concentration of serum M-protein is ≤3.5 g/L and eGFR is >30 mL/min/1.73 m (sensitivity (S): 100 %, specificity (Sp): 49 %, negative-predictive value (NPV): 100 %) the probability of finding M-protein in urine is negligible. Patients with alpha heavy chain have a higher probability of having M-protein in urine. Thus, when the heavy chain of the M-protein is gamma or mu, serum cut-off value can be raised up to ≤4.9 g/L (S: 97 %, Sp: 52 %, NPV: 98 %).

CONCLUSIONS

Settling these two cut-off values when a new M-protein is discovered could avoid a significant number of urine analyses, optimizing laboratory and healthcare resources.

摘要

目的

实验室检测在单克隆丙种球蛋白病的诊断中发挥着广泛作用。自国际骨髓瘤工作组（IMWG）关于单克隆丙种球蛋白病诊断指南的上次更新以来，对于尿液分析在这些疾病诊断中是否仍然相关产生了争论。

方法

我们对132例新诊断血清M蛋白患者的数据进行了一项回顾性研究。根据尿液中M蛋白的存在情况将患者分为两组，并记录不同变量，在两组之间进行统计学比较。

结果

该研究的目的是找到一个血清M蛋白临界值，在首次实验室诊断时低于该值可避免进行尿液分析。结果表明，当血清M蛋白浓度≤3.5 g/L且估算肾小球滤过率（eGFR）>30 mL/min/1.73 m²（敏感性（S）：100%，特异性（Sp）：49%，阴性预测值（NPV）：100%）时，在尿液中发现M蛋白的可能性可忽略不计。α重链患者尿液中出现M蛋白的可能性更高。因此，当M蛋白的重链为γ或μ时，血清临界值可提高至≤4.9 g/L（S：97%，Sp：52%，NPV：98%）。