Time between inhibitor detection and start of immune tolerance induction: Association with outcome in the BrazIT study.

BACKGROUND: Immune tolerance induction (ITI) is the treatment of choice for eradication of anti-factor VIII (FVIII) neutralizing alloantibodies (inhibitors) in people with inherited hemophilia A and high-responding inhibitor (PwHA-HRi). The association between ITI outcome and time elapsed between inhibitor detection and start of ITI (∆tinhi-ITI ) is debatable. OBJECTIVE: The aim of this study was to evaluate this association among a large cohort of severe PwHA-HRi. METHODS: Severe (factor VIII activity level <1%) PwHA-HRi on ITI (n = 142) were enrolled in 15 hemophilia treatment centers. PwHA-HRi were treated according to the Brazilian ITI Protocol. ITI outcomes were defined as success (i.e., recovered responsiveness to exogenous FVIII) and failure (i.e., no responsiveness to exogenous FVIII and requirement of bypassing agents to control bleeding). RESULTS: Median ages at inhibitor detection and at ITI start were 3.2 years (interquartile range [IQR], 1.6-8.1) and 6.9 years [IQR, 2.6-20.1), respectively. PwHA-HRi were stratified according to ∆tinhi-ITI quartiles: first (0.0-0.6 year), second (>0.6-1.7 year), third (>1.7-9.2 years), and fourth quartile (>9.2-24.5 years). The overall success rate was 65.5% (93/142), with no difference among first, second, third, and fourth quartiles (62.9%, 69.4%, 58.3%, and 71.4%, respectively) even after adjusting the analyses for potential confounders. CONCLUSION: In conclusion, delayed ITI start is not associated with failure of ITI in PwHA-HRi. Therefore, ITI should be offered for these patients, regardless of the time elapsed between the detection of inhibitor and the ITI start.

Error in body weight estimation leads to inadequate parenteral anticoagulation.

Parenteral anticoagulation is a cornerstone in the management of venous and arterial thrombosis. Unfractionated heparin has a wide dose/response relationship, requiring frequent and troublesome laboratorial follow-up. Because of all these factors, low-molecular-weight heparin use has been increasing. Inadequate dosage has been pointed out as a potential problem because the use of subjectively estimated weight instead of real measured weight is common practice in the emergency department (ED). To evaluate the impact of inadequate weight estimation on enoxaparin dosage, we investigated the adequacy of anticoagulation of patients in a tertiary ED where subjective weight estimation is common practice. We obtained the estimated, informed, and measured weight of 28 patients in need of parenteral anticoagulation. Basal and steady-state (after the second subcutaneous shot of enoxaparin) anti-Xa activity was obtained as a measure of adequate anticoagulation. The patients were divided into 2 groups according the anticoagulation adequacy. From the 28 patients enrolled, 75% (group 1, n = 21) received at least 0.9 mg/kg per dose BID and 25% (group 2, n = 7) received less than 0.9 mg/kg per dose BID of enoxaparin. Only 4 (14.3%) of all patients had anti-Xa activity less than the inferior limit of the therapeutic range (<0.5 UI/mL), all of them from group 2. In conclusion, when weight estimation was used to determine the enoxaparin dosage, 25% of the patients were inadequately anticoagulated (anti-Xa activity <0.5 UI/mL) during the initial crucial phase of treatment.

Oral anticoagulant therapy does not modify the bleeding pattern associated with the levonorgestrel-releasing intrauterine system in women with thrombophilia and/or a history of thrombosis.

BACKGROUND: Progestogen-only contraceptives (POCs) are suitable for women with thrombophilia and/or a history of venous thromboembolism (VTE). Several of these women, however, use oral anticoagulant therapy (OAT), which can impair the bleeding pattern associated with POC use. We evaluated the effects of OAT use on the bleeding pattern associated with the levonorgestrel-releasing intrauterine system (LNG-IUS) in women with thrombophilia and/or a history of VTE. STUDY DESIGN: This prospective cohort study followed two groups of women, all of whom were thrombophilic and/or had a history of VTE: OAT users and nonusers. Bleeding patterns, blood pressure, body mass index (BMI), weight, complete blood count and waist circumference were compared between the two groups before and 6 and 12 months after LNG-IUS insertion. RESULTS: The patient cohort consisted of 33 women aged 18 to 45 years old, including 16 OAT users and 17 nonusers. Body weight increased by 3.9% and BMI by 3.8% in OAT users 12 months after LNG-IUS insertion. Hemoglobin and hematocrit levels increased by approximately 10% in both groups. There was no difference between the groups in bleeding patterns, with amenorrhea being the most frequent pattern in both groups (41.2% each) 12 months after LNG-IUS insertion. OAT did not increase the frequency of prolonged and/or frequent bleeding. CONCLUSION: OAT users and nonusers had similar bleeding patterns after insertion of the LNG-IUS. Hemoglobin and hematocrit levels increased in both groups.

Tromboprofilaxia na gestação e no puerpério / Thromboprophylaxis in pregnancy and puerperium

O tromboembolismo venoso é uma importante causa de morbimortalidade durante a gestação e o puerpério. Entretanto, a necessidade de tromboprofilaxia durante a gestação permanece um assunto controverso na literatura. Restam dúvidas sobre quando e como iniciar a profilaxia, que grau de anticoagulação deve ser atingido e como selecionar as pacientes de risco para tromboembolismo venoso. As modificações do sistema hemostático promovidas pelo ciclo gravídico-puerperal fazem com que a gestação e o puerpério se tornem fatores de risco adquiridos para eventos tromboembólicos. As recomendações atuais de investigação e tromboprofilaxia estão de acordo com estimativas de risco para tromboembolismo venoso, baseadas nos antecedentes pessoais da gestante e na presença de fatores hereditários. A tendência dos últimos estudos é de individualização dos casos e uso da tromboprofilaxia em situações de alto risco, como história pessoal de tromboembolismo venoso, obesidade mórbida, trombofilias hereditárias e adquiridas. Vale ressaltar a importância de a paciente participar da decisão pela tromboprofilaxia durante a gestação e o puerpério, depois de esclarecida sobre riscos e benefícios desta opção terapêutica. A atualização sobre o tema facilita respostas a eventuais questionamentos, sem a intenção de esgotá-los, mas de enfatizar a necessidade de buscar melhor assistência à população obstétrica de risco