Research Institute of Internal Medicine, Oslo University Hospital, Rikshospitalet, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway; Department of Haematology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
Haemophilia. 2014 Jan;20(1):141-6. doi: 10.1111/hae.12256. Epub 2013 Aug 28.
Bleeding tendency is weakly correlated with the activity of factor VII (FVII) in the plasma of patients with FVII deficiency. A laboratory method for predicting bleeding risk in patients with this coagulation disorder is lacking. We investigated whether global coagulation assays, specifically thromboelastography (TEG) and thrombin generation assay (TGA), could be used to predict bleeding risk. We also sought to identify factors that may explain the differences in bleeding phenotype observed among individuals with severe FVII deficiency. The study comprised 12 patients with severe FVII deficiency (FVII activity <1%). Eleven patients were homozygous for the Gln100Arg mutation and one patient was compound heterozygous. Clinically, 10 patients had increased haemorrhagic diathesis, whereas two patients were asymptomatic. Blood sampling was performed at baseline for TEG and TGA analyses. The platelet aggregation assay was performed and the plasma level of anticoagulation inhibitors and thrombophilic risk factors assessed. No difference in the TEG and TGA results was observed in all FVII-deficient individuals. The level of free tissue factor pathway inhibitor was within the normal range and similar in symptomatic and asymptomatic subjects. None of the participants had the FV Leiden mutation, prothrombin gene mutation, or abnormal anticoagulant inhibitor levels. Asymptomatic subjects showed normal platelet aggregation. These data suggested that TEG and TGA were not suitable methods for predicting the clinical phenotype in FVII-deficient subjects.
出血倾向与 FVII 缺乏症患者血浆中 FVII 活性呈弱相关。目前缺乏针对这种凝血障碍患者出血风险的实验室预测方法。我们研究了是否可以使用全球凝血检测，特别是血栓弹力图（TEG）和凝血酶生成试验（TGA）来预测出血风险。我们还试图确定可能解释严重 FVII 缺乏症患者出血表型差异的因素。该研究纳入了 12 名严重 FVII 缺乏症患者（FVII 活性 <1%）。11 名患者为 Gln100Arg 突变纯合子，1 名患者为复合杂合子。临床方面，10 名患者有出血倾向增加，而 2 名患者无症状。在基线时进行 TEG 和 TGA 分析时进行了采血。进行了血小板聚集试验，并评估了抗凝抑制剂和血栓形成风险因素的血浆水平。所有 FVII 缺乏个体的 TEG 和 TGA 结果无差异。游离组织因子途径抑制剂水平在正常范围内，且在有症状和无症状患者中相似。无参与者存在 FV Leiden 突变、凝血酶原基因突变或异常抗凝抑制剂水平。无症状患者的血小板聚集正常。这些数据表明，TEG 和 TGA 不适合用于预测 FVII 缺乏症患者的临床表型。
