Pediatric severe factor XI deficiency: A multicenter study

Assaf Arie Barg, Sarina Levy-Mendelovich, Ivan Budnik, Noa Mandel-Shorer, Rima Dardik, Einat Avishai, Tami Brutman-Barazani, Aviya Dvir Ifrah, Liat Oren-Malek, Joanne Yacobovich, Oded Gilad, Sigal Nakav, Yariv Fruchtman, Shoshana Revel-Vilk, Hagit Miskin, Gili Kenet

Research output: Contribution to journalArticlepeer-review

3 Scopus citations


Background: Factor XI (FXI) deficiency is a rare autosomal recessive bleeding disorder. Only scarce publications address its clinical features in children. The increased prevalence of FXI deficiency in Israel enabled data collection for this large multicenter cohort study. Objective: Some hemostatic challenges may be unique or more common in children, such as bleeding in the neonatal period or trauma-related injury. The current study was designed to explore the potential impact of these differences in children with severe FXI deficiency. Methods: Medical files of all children with FXI level under 15% followed at five tertiary centers were evaluated. The retrieved data comprised demographic and clinical characteristics, including bleeding episodes, surgical interventions, treatment strategies, as well as laboratory features. Results: Sixty children, whose median age at diagnosis was 4.2 years and their median FXI level was 4%, were included. Three children experienced triggered intracranial hemorrhage (ICH) and two children had major bleeds. No bleeding complications occurred in surgeries in which hemostatic treatment consisting mostly of tranexamic acid or fresh frozen plasma was applied (n = 45). In contrast, excessive bleeding was noted in 25% of surgical procedures performed without hemostatic preparation (p =.002). Conclusion: This study's findings confirm the generally favorable outcome of this rare bleeding disorder, with no spontaneous bleeds or cases of perinatal ICH. Nonetheless, proper diagnosis and adequate hemostasis in the surgical setting are imperative. Unlike previous studies in adults, our pediatric study suggests an association between the severity of FXI deficiency and bleeding tendency.

Original languageEnglish
Article numbere29545
JournalPediatric Blood and Cancer
Issue number3
StatePublished - Mar 2022
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2021 Wiley Periodicals LLC


All authors have no competing interests, except Gili Kenet who receives grant and research support from Alnylam, Bayer, BPL, Opko Biologics, Pfizer, and Shire and honoraria for consultancy/lectures from Alnylam, Bayer, CSL, Opko Biologics, Pfizer, Takeda, and ROCHE. Assaf A. Barg receives honoraria for lectures from ROCHE. Shoshana Revel‐Vilk receives honoraria and research funding from Takeda, Pfizer, and Sanofi/Genzyme.

FundersFunder number
Takeda Pharmaceutical Company
Sanofi Genzyme
Commonwealth Serum Laboratories


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