Management of rare inherited bleeding disorders: Proposals of the French Reference Centre on Haemophilia and Rare Coagulation Disorders

INTRODUCTION

The rare coagulation disorders may present significant difficulties in diagnosis and management. In addition, considerable inter-individual variation in bleeding phenotype is observed amongst affected individuals, making the bleeding risk difficult to assess in affected individuals. The last international recommendations on rare inherited bleeding disorders (RIBDs) were published by the United Kingdom Haemophilia Centre Doctors' Organisation in 2014. Since then, new drugs have been marketed, news studies on surgery management in patients with RIBD have been published, and new orphan diseases have been described.

AIM

Therefore, the two main objectives of this review, based on the recent recommendations published by the French Reference Centre on Haemophilia and Rare Bleeding Disorders, are: (i) to briefly describe RIBD (clinical presentation and diagnostic work-up) to help physicians in patient screening for the early detection of such disorders; and (ii) to focus on the current management of acute haemorrhages and long term prophylaxis, surgical interventions, and pregnancy/delivery in patients with RIBD.

Paroxysmal nocturnal hemoglobinuria and vascular liver disease: Eculizumab therapy decreases mortality and thrombotic complications

A total of 2%-10% of patients with vascular liver disease (VLD) have paroxysmal nocturnal hemoglobinuria (PNH). Eculizumab reduces complement-mediated haemolytic activity in PNH. This study was aimed at assessing the impact of eculizumab on VLD outcome. Retrospective cohort of PNH patients, in Valdig registry, who had VLD diagnosed between 1997 and 2019 is considered. Eculizumab was the exposure of interest. Studied outcomes were death, venous thrombosis, bleeding, arterial ischemic event, infection, and liver-related complications. We compared survival and new thrombotic events from PNH/VLD cohort to Envie2 non-PNH cohort. Sixty-two patients (33 women), median age 35 years (28-48) and median follow-up VLD diagnosis 4.7 years (1.2-9.5), were included. Clone size was 80% (70-90), median hemoglobin concentration was 10.0 g/dl (8-11), and lactate dehydrogenase (LDH) was 736 IU (482-1744). Forty-two patients (68%) had eculizumab; median exposure time was 40.1 [9.3-72.6] months. Mortality was significantly lower in exposed versus nonexposed period: 2.6 versus 8.7 per 100 (PY), incidence rate ratio (IRR) was 0.29, 95% CI (0.1-0.9), p = .035. Thrombosis recurrence occurred less frequently during the exposure to eculizumab: 0.5 versus 2.8 per 100 PY, IRR 0.22 (0.07-0.64). Other secondary end points (i.e., bleeding, arterial ischemic lesions, infection, and liver complications) were less common during the exposure to eculizumab, although not reaching statistical significance. Six-year thrombosis-free survival was 70%, 95% CI [0.60-0.83] for PNH cohort and 83%, 95% CI [0.70-1.00] for non-PNH Envie 2 patients, (p < .001). In conclusion, patients with PNH and VLD are at higher risk of recurrent thrombosis than non-PNH patients. Eculizumab is significantly associated with a lower mortality and less thrombotic recurrence in patients with PNH and VLD.

Acquired factor V inhibitor: a nation-wide study of 38 patients

Acquired factor V inhibitor (AFVI) is an extremely rare disorder that may cause severe bleeding. To identify factors associated with bleeding risk in AFVI patients, a national, multicentre, retrospective study was made including all AFVI patients followed in 21 centres in France between 1988 and 2015. All patients had an isolated factor V (FV) deficiency <50% associated with inhibitor activity. Patients with constitutional FV deficiency and other causes of acquired coagulation FV deficiencies were excluded. The primary outcome was incident bleeding and factors associated with the primary outcome were identified. Thirty-eight (74 [36-100] years, 42·1% females) patients with AFVI were analysed. Bleeding was reported in 18 (47·4%) patients at diagnosis and in three (7·9%) during follow-up (7 [0·2-48.7] months). At diagnosis, FV was <10% in 31 (81·6%) patients. Bleeding at diagnosis was associated with a prolonged prothrombin time that strongly correlated with the AFVI level measured in plasma {r = 0·63, 95% confidence interval (CI) [0·36-0·80], P < 0·05}. Bleeding onset during follow-up was associated with a slow AFVI clearance (P < 0·001). The corresponding receiver operating characteristics curve showed that AFVI clearance was predictive of bleeding onset with an AFVI clearance of seven months with a sensitivity of 100% (95% CI: 29-100) and a specificity of 86% (95% CI: 57-98, P = 0·02). Kaplan-Meier analysis showed that AFVI clearance >7 months increased the risk of bleeding by 8 (95% CI: [0·67-97], P = 0·075). Prothrombin time at diagnosis and time for clearance of FV inhibitor during follow-up are both associated with bleeding in patients with AFVI.

Comparative Analysis of a French Prospective Series of 144 Patients with Heparin-Induced Thrombocytopenia (FRIGTIH) and the Literature

Background Heparin-induced thrombocytopenia (HIT) is a rare complication of heparin treatments, and only a few large patient cohorts have been reported. In this study, biological and clinical data from 144 French patients with HIT were analyzed in comparison with the literature.

Methods The diagnosis of HIT was confirmed in all patients by an immunoassay combined with serotonin release assay. In the literature, only cohorts of at least 20 HIT patients published from 1992 were selected for a comparative analysis.

Results Two-thirds of patients were hospitalized in surgery and most were treated with unfractionated heparin (83.2% vs. 16.8% with low molecular weight heparin only). Thrombotic events in 54 patients (39.7%) were mainly venous (41/54). However, arterial thrombosis was more frequent after cardiac surgery (13.2% vs. 2.4% in other surgeries, p = 0.042) with a shorter recovery time (median = 3 vs. 5 days, p < 0.001). The mortality rate was lower in our series than in the 22 selected published studies (median = 6.3% vs. 15.9%). Three genetic polymorphisms were also studied and homozygous subjects FcγRIIA RR were more frequent in patients with thrombosis (37.8 vs. 18.2% in those without thrombosis, p = 0.03).

Conclusion This study shows that the mortality rate due to HIT has recently decreased in France, possibly due to earlier diagnosis and improved medical care. It also confirms the strong association between polymorphism FcγRIIA H131R and thrombosis in HIT.

Determinants of adherence and consequences of the transition from adolescence to adulthood among young people with severe haemophilia (TRANSHEMO): study protocol for a multicentric French national observational cross-sectional study

INTRODUCTION

Severe haemophilia is a rare disease characterised by spontaneous bleeding from early childhood, which may lead to various complications, especially in joints. It is nowadays possible to avoid these complications thanks to substitutive therapies for which the issue of adherence is major. The transition from adolescence to adulthood in young people with severe haemophilia is a critical period as it is associated with a high risk of lack of adherence to healthcare, which might have serious consequences on daily activities and on quality of life.

METHODS AND ANALYSIS

We present the protocol for a cross-sectional, observational, multicentric study to assess the differences between adolescents and young adults with severe haemophilia in France through the transition process, especially on adherence to healthcare. This study is based on a mixed methods design, with two complementary and consecutive phases, comparing data from a group of adolescents (aged 14-17 years) with those from a group of young adults (aged 20-29 years). The quantitative phase focuses on the determinants (medical, organisational, sociodemographic and social and psychosocial and behavioural factors) of adherence to healthcare (considered as a marker of the success of transition). The qualitative phase explores participants' views in more depth to explain and refine the results from the quantitative phase. Eligible patients are contacted by the various Haemophilia Treatment Centres participating in the French national registry FranceCoag.

ETHICS AND DISSEMINATION

The study was approved by the French Ethics Committee and by the French National Agency for Medicines and Health Products Safety (number: 2016-A01034-47). Study findings will be disseminated to the scientific and medical community in peer-reviewed journals and presented at scientific meetings. Results will be popularised to be communicated via the French association for people with haemophilia to participants and to the general public.

TRIAL REGISTRATION NUMBER

NCT02866526; Pre-results.

Type 2 diabetes mellitus as a risk factor for intestinal resection in patients with superior mesenteric vein thrombosis

BACKGROUND & AIMS

The most serious complication of acute mesenteric vein thrombosis (MVT) is acute intestinal ischaemia requiring intestinal resection or causing death. Risk factors for this complication are unknown. To identify risk factors for severe intestinal ischaemia leading to intestinal resection in patients with acute MVT.

METHODS

We retrospectively analysed consecutive patients seen between 2002 and 2012 with acute MVT in 2 specialized units. Patients with cirrhosis were excluded. We compared patients who required intestinal resection to patients who did not.

RESULTS

Among 57 patients, a local risk factor was identified in 14 (24%) patients, oral contraceptive use in 16 (29%), and at least one or more other systemic prothrombotic condition in 25 (44%). Five (9%) patients had diabetes mellitus (DM), 33 (58%) had overweight or obesity, 9 (18%) had hypertriglyceridemia and 10 (19%) had arterial hypertension. Eleven patients (19%) underwent intestinal resection. DM was significantly associated with intestinal resection (P = 0.02) while local factors or prothrombotic conditions were not. Computed tomography (CT) scans performed at diagnosis found that occlusion of second order radicles of the superior mesenteric vein was more frequently observed in patients who underwent intestinal resection (P = 0.009).

CONCLUSIONS

In acute MVT, patients with underlying DM have an increased risk of requiring intestinal resection. Neither local factors nor systemic prothrombotic conditions are associated with intestinal resection. When CT scan shows the preservation of second order radicles of the superior mesenteric vein, the risk of severe resection is low.

Absorption and Efficacy of Acetylsalicylic Acid in Patients With Short Bowel Syndrome

Background: The patients with a short bowel (SB) frequently require antiplatelet therapy. Resection of the bowel is likely to modify the absorption and first-pass effect of drugs. No data on the absorption and efficacy of the cardiovascular dose of aspirin (75-160 mg) in these patients have been published. Objective: To evaluate the efficacy of a low dose of aspirin in patients with SB caused by mesenteric ischemia. Methods: The efficacy of a low dose of aspirin was assessed in 10 consecutive SB patients, both 1 hour and 24 hours after administration (peak and trough value, respectively). The primary criterion was the inhibition of platelet aggregation, as assessed by light transmission aggregometry, triggered with 0.5 mg/mL arachidonic acid. Biological efficacy of aspirin was also evaluated by serum thromboxane B2 value and by platelet function analyzer-100. Results: At its peak value, aspirin had the expected efficacy, as demonstrated both by light transmission aggregometry and the other methods. However, 24 hours after administration, as many as 30% of patients had lost the pharmacological efficacy of their aspirin. Conclusion: We show for the first time that with at least 30 cm of small intestine, all patients with SB absorb sufficient oral aspirin in a cardiovascular dose to rapidly exert the expected level of antiplatelet activity. But given only once daily, aspirin does not provide stable 24-hour antiplatelet protection in 30% of patients, because of increased platelet turnover, as usually observed in patients with extensive vascular pathology, diabetes, or inflammation.