Treatment of Homozygous Type II Antithrombin Heparin-Binding Site Deficiency in Pregnancy.

Hilde Fiskvik,Anne F Jacobsen,Carola E Henriksson,Eva-Marie Jacobsen,Nina Iversen,John P Geisler

doi:10.1155/2021/4393821

Hilde Fiskvik, Anne F Jacobsen + Show 4 more

Open Access

https://doi.org/10.1155/2021/4393821

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Abstract

Pregnancy is associated with an increased risk of venous thromboembolism (VTE). Previous VTE and severe thrombophilia are important risk factors. Our case was a 36-year-old woman, gravida 6, para 0, with antithrombin (AT) deficiency caused by a homozygous mutation in the heparin-binding site (HBS). Her history included seven prior VTEs, three early and two late pregnancy losses. She was prophylactically treated with both human plasma-derived AT concentrate (hpATC) and low molecular weight heparin (LMWH), resulting in a successful 6th pregnancy and a healthy live born baby. There is limited evidence and guidance on the management of AT deficiency in pregnancy. Dosing and monitoring of anticoagulants, alone or together with hpATC, must be based on individual risk assessment. The severity of clinical manifestations varies with the type of AT deficiency. Characterization of the AT mutation may aid in the decision-making process and optimize pregnancy outcomes.

Highlights

AT is a major inhibitor of thrombin (factor (F) IIa), FXa, and several other coagulation factors
HpATC was administered for five days, warfarin was bridged with dalteparin, and she was discharged with an INR target of 2.5
We argue that the characterization of the subclass of AT deficiency, type, and site of mutation must be considered when deciding prophylaxis and treatment in pregnancy

Summary

Introduction

AT is a major inhibitor of thrombin (factor (F) IIa), FXa, and several other coagulation factors. The prevalence of hereditary AT deficiency is 0.020.2% in the general population [2] and 1-5% in patients with VTE [3]. Type II AT deficiency is classified into three subtypes based on the site of the causative mutation and the functional consequences, reactive site (RS), HBS, or pleiotropic effects. Heterozygous type II AT RS deficiency is reported to have the greatest potential for thrombosis, and heterozygous type II AT HBS deficiency the least. Case publications and small studies of patients with homozygous HBS mutations imply that this subgroup is associated with an extreme high risk of thrombosis and pregnancy complications [4,5,6,7,8,9,10]

Case Presentation

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