Caron C, Meley R, Le Cam Duchez V, Aillaud M F, Lavenu-Bombled C, Dutrillaux F, Flaujac C, Ryman A, Ternisien C, Lasne D, Galinat H, Pouplard C
Laboratoire d'Hématologie-Hémostase, CHU Lille, Lille, France.
Laboratoire d'Hématologie-Hémostase, CHU Saint-Etienne, Saint-Etienne, France.
Int J Lab Hematol. 2017 Jun;39(3):279-285. doi: 10.1111/ijlh.12621. Epub 2017 Mar 20.
Factor XIII (FXIII) deficiency is a rare hemorrhagic disorder whose early diagnosis is crucial for appropriate treatment and prophylactic supplementation in cases of severe deficiency. International guidelines recommend a quantitative FXIII activity assay as first-line screening test. FXIII antigen measurement may be performed to establish the subtype of FXIII deficiency (FXIIID) when activity is decreased.
The aim of this multicenter study was to evaluate the analytical and diagnostic levels of performance of a new latex immunoassay, K-Assay FXIII reagent from Stago, for first-line measurement of FXIII antigen. Results were compared to those obtained with the Berichrom FXIII chromogenic assay for measurement of FXIII activity. Of the 147 patient plasma samples, 138 were selected for analysis.
The accuracy was very good, with intercenter reproducibility close to 7%. Five groups were defined on FXIII activity level (<5% (n = 5), 5%-30% (n = 23), 30%-60% (n = 17), 60%-120% (n = 69), above 120% (n = 24)), without statistical differences between activity and antigen levels (P value >0.05). Correlation of the K-Assay with the Berichrom FXIII activity results was excellent (r = 0.919). Good agreement was established by the Bland and Altman method, with a bias of +9.4% on all samples, and of -1.4% for FXIII levels lower than 30%. One patient with afibrinogenemia showed low levels of Berichrom FXIII activity but normal antigen level and clot solubility as expected.
The measurement of FXIII antigen using the K-Assay is a reliable first-line tool for detection of FXIII deficiency when an activity assay is not available.
凝血因子 XIII（FXIII）缺乏症是一种罕见的出血性疾病，早期诊断对于严重缺乏症患者的适当治疗和预防性补充至关重要。国际指南推荐定量 FXIII 活性测定作为一线筛查试验。当活性降低时，可进行 FXIII 抗原测量以确定 FXIII 缺乏症（FXIIID）的亚型。
这项多中心研究的目的是评估一种新型乳胶免疫测定法（来自 Stago 的 K 测定 FXIII 试剂）用于 FXIII 抗原一线测量的分析和诊断性能水平。将结果与使用 Berichrom FXIII 显色测定法测量 FXIII 活性所获得的结果进行比较。在 147 份患者血浆样本中，选择了 138 份进行分析。
准确性非常好，中心间再现性接近 7%。根据 FXIII 活性水平定义了五组（<5%（n = 5）、5%-30%（n = 23）、30%-60%（n = 17）、60%-120%（n = 69）、高于 120%（n = 24）），活性和抗原水平之间无统计学差异（P 值>0.05）。K 测定法与 Berichrom FXIII 活性结果的相关性极佳（r = 0.919）。通过 Bland 和 Altman 方法建立了良好的一致性，所有样本的偏差为 +9.4%，FXIII 水平低于 30%时的偏差为 -1.4%。一名无纤维蛋白原血症患者的 Berichrom FXIII 活性水平较低，但抗原水平和凝块溶解性正常，符合预期。
当无法进行活性测定时，使用 K 测定法测量 FXIII 抗原是检测 FXIII 缺乏症的可靠一线工具。
