Department of Pathophysiology and Transplantation, Università degli Studi di Milano and Luigi Villa Foundation, Milan, Italy.
Angelo Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
J Thromb Haemost. 2017 Sep;15(9):1728-1736. doi: 10.1111/jth.13772. Epub 2017 Aug 17.
Essentials A strong association between bleeding severity and FXIII activity level (FXIII:C) was shown. The range 5-30 IU dL of FXIII:C was associated with a high variability of bleeding severity. The PROspective study confirmed the association between FXIII:C activity and bleeding severity.
C of 15 IU dL is a proposed target to start prophylaxis for prevention of major bleeding.
Background Congenital factor XIII (FXIII) deficiency is a rare bleeding disorder associated with significant bleeding manifestations. The European Network of Rare Bleeding Disorders (EN-RBD) study, performed from 2007 to 2010, showed a strong association between bleeding severity and FXIII activity in plasma of patients with FXIII deficiency. Among these patients, variable levels of FXIII activity, from undetectable to 30%, were associated with a wide range of bleeding severity. Objectives and patients The present cross-sectional study, in the frame of the PRO-RBDD project, a prospective cohort study, analyzed data of 64 patients with FXIII deficiency and different types of clinical and laboratory severity. Results The results of this analysis confirmed that FXIII coagulant activity in plasma is well associated with clinical severity of patients. In addition, 15 IU dL of FXIII activity was identified to be the level under which the probability of spontaneous major bleeding sharply increases (from 50% for levels of 15 IU dL to more than 90% for levels of 5 IU dL or lower). Conclusion The PRO-RBDD study suggests a FXIII coagulant activity level of 15 IU dL as a target to start prophylaxis in order to prevent major bleedings, such as central nervous system or gastrointestinal tract hemorrhages.
先天性因子 XIII（FXIII）缺乏症是一种罕见的出血性疾病，与明显的出血表现有关。欧洲罕见出血性疾病网络（EN-RBD）研究于 2007 年至 2010 年进行，该研究表明 FXIII 缺乏症患者血浆中出血严重程度与 FXIII 活性之间存在很强的关联。在这些患者中，FXIII 活性水平从检测不到到 30%不等，与广泛的出血严重程度相关。
本横断面研究是 PRO-RBDD 项目的一部分，该项目是一项前瞻性队列研究，分析了 64 例 FXIII 缺乏症患者不同类型的临床和实验室严重程度的数据。
这项分析的结果证实，血浆中的 FXIII 凝血活性与患者的临床严重程度密切相关。此外，15 IU/dL 的 FXIII 活性被确定为自发性大出血概率急剧增加的水平（从 15 IU/dL 水平的 50%到 5 IU/dL 或更低水平的 90%以上）。
PRO-RBDD 研究建议 FXIII 凝血活性水平为 15 IU/dL，作为开始预防以防止主要出血（如中枢神经系统或胃肠道出血）的目标。
