Cramer Thomas J, Anderson Kristin, Navaz Karanjia, Brown Justin M, Mosnier Laurent O, von Drygalski Annette
University of California San Diego, Department of Medicine, 9500 Gillman Drive, San Diego, CA 92093, USA.
University of California San Diego, Department of Neurosciences, 9500 Gillman Drive, San Diego, CA 92093, USA.
Blood Cells Mol Dis. 2016 Mar;57:8-12. doi: 10.1016/j.bcmd.2015.11.004. Epub 2015 Nov 10.
In congenital Factor (F) VII deficiency bleeding phenotype and intrinsic FVII activity levels don't always correlate. Patients with FVII activity levels <30% appear to have a higher bleeding propensity, but bleeding can also occur at higher FVII activity levels. Reasons for bleeding at higher FVII activity levels are unknown, and it remains challenging to manage such patients clinically.
A 19year old male with spontaneous intracranial hemorrhage and FVII activity levels of 44%, requiring emergent surgical intervention and a strategy for FVII replacement. Genotyping showed the rare heterozygous FVII 9729del4 mutation. Bleed evacuation was complicated by epidural abscess requiring craniectomy, bone graft procedures, and prolonged administration of recombinant human (rh) activated FVII (FVIIa). The patient recovered without neurological deficits, and remains on prophylactic low dose treatment with rhFVIIa in relation to risky athletic activities.
For clinicians, it is important to recognize that effects of rhFVIIa within these pathways are independent of its contribution to blood clot formation and cannot be assessed by clotting assays. Reduced FVII levels should therefore not be dismissed, as even a mild reduction may result in spontaneous bleeding. Treatment of mild FVII deficiency requires a careful case-by-case approach, based on the clinical scenario.
在先天性凝血因子(F)VII缺乏症中,出血表型与FVII内在活性水平并不总是相关。FVII活性水平<30%的患者似乎有更高的出血倾向,但在FVII活性水平较高时也可能发生出血。FVII活性水平较高时出血的原因尚不清楚,对这类患者进行临床管理仍然具有挑战性。
一名19岁男性,发生自发性颅内出血,FVII活性水平为44%,需要紧急手术干预和FVII替代策略。基因分型显示罕见的杂合性FVII 9729del4突变。血肿清除术因硬膜外脓肿而复杂化,需要进行颅骨切除术、骨移植手术,并延长重组人(rh)活化FVII(FVIIa)的给药时间。患者康复后无神经功能缺损,对于有风险的体育活动,仍接受rhFVIIa预防性低剂量治疗。
对于临床医生来说,重要的是要认识到rhFVIIa在这些途径中的作用与其对血凝块形成的贡献无关,并且不能通过凝血试验进行评估。因此,不应忽视FVII水平的降低,因为即使是轻度降低也可能导致自发性出血。轻度FVII缺乏症的治疗需要根据临床情况,采取谨慎的个体化方法。