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.

Reccurrent F8 Intronic Deletion Found in Mild Hemophilia A Causes Alu Exonization

Incorporation of distant intronic sequences in mature mRNA is an underappreciated cause of genetic disease. Several disease-causing pseudoexons have been found to contain repetitive elements such as Alu elements. This study describes an original pathological mechanism by which a small intronic deletion leads to Alu exonization. We identified an intronic deletion, c.2113+461_2113+473del, in the F8 intron 13, in two individuals with mild hemophilia A. In vivo and in vitro transcript analysis found an aberrant transcript, with an insertion of a 122-bp intronic fragment (c.2113_2114ins2113+477_2113+598) at the exon 13-14 junction. This out-of-frame insertion is predicted to lead to truncated protein (p.Gly705Aspfs^∗37). DNA sequencing analysis found that the pseudoexon corresponds to antisense AluY element and the deletion removed a part of the poly(T)-tail from the right arm of these AluY. The heterogenous nuclear riboprotein C1/C2 (hnRNP C) is an important antisense Alu-derived cryptic exon silencer and binds to poly(T)-tracts. Disruption of the hnRNP C binding site in AluY T-tract by mutagenesis or hnRNP C knockdown using siRNA in HeLa cells reproduced the effect of c.2113+461_2113+473del. The screening of 114 unrelated families with mild hemophilia A in whom no genetic event was previously identified found a deletion in the poly(T)-tail of AluY in intron 13 in 54% of case subjects (n = 61/114). In conclusion, this study describes a deletion leading to Alu exonization found in 6.1% of families with mild hemophila A in France.

Critical appraisal of organ procurement under Maastricht 3 condition

The ethics committee of the French Society of Anesthesia and Intensive Care (Sfar) has been requested by the French Biomedical Agency to consider the issue of organ donation in patients after the decision to withdraw life-supportive therapies has been taken. This type of organ donation is performed in the USA, Canada, the United Kingdom, the Netherlands and Belgium. The three former countries have published recommendations formalizing procedures and operations. The French Society of Anesthesia and Intensive Care (Société française d'anesthésie et de reanimation [Sfar]) ethics committee has considered this issue and envisioned the different aspects of the whole process. Consequently, it sounded a note of caution regarding the applicability of this type of organ procurement in unselected patients following a decision to withdraw life-supportive therapies. According to French regulations concerning organ procurement in brain-dead patients, the committee stresses the need to restrict this specific way of procurement to severely brain-injured patients, once confirmatory investigations predicting a catastrophic prognosis have been performed. This suggests that the nature of the confirmatory investigation required should be formalized by the French Biomedical Agency on behalf of the French parliamentarians, which should help preserve population trust regarding organ procurement and provide a framework for medical decision. This text has been endorsed by the Sfar.

[Citation errors: Uplavici (for Hlava) and William the Silent (for Jules Verne and Mignet)]

A certain 'O Uplavici' was cited for more than fifty years, although he had never existed. This error probably came from a misinterpretation of the Czech language, in which the real author's name--Hlava--can mean 'Title'. It was finally recognized, which was not the case for the author of the sentence: 'I have no need of hope to take action, nor of success to persevere', it is still regularly attributed in France to William I, Prince of Orange, called the Silent. It is a mistake, and no serious reference certifies that an historical figure would have pronounced this sentence. It was written by the historian Mignet in 1841, to describe the character of William III, Prince of Orange and King of England. It was then used in 1875 by Jules Verne, to describe a character in 'The Mysterious Island'.

Bayesian logic in statistical test control: application to coagulation factor VIII assay

Coagulation factor VIII was assayed around the critical concentration of 80 U/dl, which is optimal for postoperative haemostasis in haemophiliac patients, in order to assess the use of Bayesian logic in interpreting internal quality control results during a change of reagent or control batch. A mathematical model based on Bayesian inference, requiring no preliminary control-plan phase, was compared with a classical approach, which necessarily involves performing a preliminary phase. Tsiamyrtzis and Hawkins' Bayesian model proved applicable to rapid statistical control of factor VIII assay, detecting shift at least as efficiently as classical approaches, which depend on running the kind of costly and controversial preliminary control phase recommended by Shewhart.

Evaluation of thrombin generating capacity in plasma from patients with haemophilia A and B

In haemophilia patients, a relationship is usually observed between the clinical expression of the disease and plasmatic factor VIII/factor IX (FVIII/FIX) activity. However, it is known from clinical experience, that some haemophilia patients, despite similar FVIII/FIX plasma levels, could exhibit different bleeding phenotype. After determining preanalytical test conditions, we evaluated the thrombin generation capacity from haemophilia plasma samples in various conditions and the potential usefulness of thrombin generation test (TGT) in haemophilia patients. In a series of 46 haemophilia patients (34 haemophilia A and 12 haemophilia B patients), we found a significant correlation between plasmatic FVIII/FIX levels and endogenous thrombin potential (ETP), peak and time to peak obtained by thrombin generation measurement. In addition, a correlation was found between severe clinical bleeding phenotype and ETP. Our results suggest that TGT could be a promising tool to evaluate haemostasis capacity in patients with haemophilia. Our ex vivo results, obtained 24 hours after FVIII concentrate administration, showed that in patients presenting similar plasmatic FVIIII levels, thrombin generation capacity may be significantly different. These results suggest that in patients with haemophilia, TGT could be useful for individually tailoring prophylactic regimens as well as for adapting clotting factors infusions in surgical situations, in addition to FVIII/FIX plasma clotting activities.

Mortality related to anaesthesia in France: analysis of deaths related to airway complications

Death certificates from the French national mortality database for the calendar year 1999 were reviewed to analyse cases in which airway complications had contributed to peri-operative death. Respiratory deaths (and comas) found in a previous national 1978-82 French survey (1:7960; 95% CI 1:12,700 to 1:5400) were compared with the death rate found in the present one: 1:48,200 (95% CI 1:140,000 to 1:27,500). In 1999, deaths associated with failure of the breathing circuit and equipment were no longer encountered and no death was found to be related to undetected hypoxia in the recovery unit. Deaths related to difficult intubation also occurred at a lower rate than in the previous report (1:46,000; 95% CI 1:386,000 to 1:13,000) in 1978-82 vs 1:176,000 (95% CI 1:714,000 to 1:46,000) in 1999, a fourfold reduction. In most cases, there were both inadequate practice and systems failure (inappropriate communication between staff, inadequate supervision, poor organisation). This large French survey shows that deaths associated with respiratory complications during anaesthesia have been strikingly reduced during this 15-year period.

[Autopsy of a common error: the introduction of curare in Europe by W. Raleigh]

One of the most erroneous and repeated assertion in the history of pharmacology for anaesthetists is to say that "the curare was introduced in Europe by Sir Walter Raleigh under the name of ourari". On the contrary, the names to be reminded are: Lawrence Keymis for the first citation of the word ourari, José Gumilla for the word curare and the description of its effects, Charles-Marie de La Condamine for the import of the first known samples. The mistake was initiated by Alexander von Humboldt and developed by the physiologist Münter, a student of Johannes Müller, quoted by Claude Bernard. The repetition of this error was facilitated by the world diffusion of Claude Bernard's work.