Improved treatment feasibility in children with hemophilia using arteriovenous fistulae: the results after seven years of follow-up

Handwriting Analysis in Children and Adolescents with Hemophilia: A Pilot Study

Background: Handwriting is a complex task that requires the integrity of different sensorimotor components to be performed successfully. Patients with hemophilia suffer from recurrent joint bleeds that may occur in the elbow, causing elbow dysfunction with handwriting performance impairment. In our study, we described instrumental dysgraphia that is related to functional disturbances. This pilot study aims to evaluate the handwriting performance in a group of patients with hemophilia. Methods: The study was performed at the Angelo Bianchi Bonomi Hemophilia and Thrombosis Center in Milan. Boys with severe and moderate hemophilia A and B regularly followed-up at that Center, with age between 6–19 years, were eligible. Patients were invited to the Center for one multidisciplinary evaluation of the upper limbs that included: Clinical examination, surface electromyography, and handwriting assessment. Results: All patients, but one, completed handwriting assessment. Overall, 14/19 (74%) had abnormal handwriting, which was overt instrumental dysgraphia in six (32%). There was no difference in Hemophilia Joint Health Score (HJHS) between dysgraphic and non-dysgraphic boys, while surface electromyography (sEMG) revealed a prevalence of flexor muscles of the upper limb in dysgraphic as compared with non-dysgraphic boys. Conclusions: The rather high prevalence of instrumental dysgraphia found in this pilot study deserves a further development of this preliminary experience by increasing the number of examined patients and comparing them with a control group, including quality of life and psychological assessment.

Arteriovenous shunts as venous access in children with haemophilia

INTRODUCTION

Venous access is essential in patients with haemophilia for administration of factor concentrates. Peripheral venipuncture may be challenging, particularly in young children or during immune tolerance induction (ITI). Central venous access devices (CVADs) carry a significant risk for complications. An alternative for venous access is peripheral arteriovenous shunts (AVSs), but there is sparse documentation in the literature. The aim of this study was to document our experience with AVS over 12 years in 27 boys with severe haemophilia.

METHODS

For AVS creation, a subcutaneous vein is connected end-to-side with an artery at the wrist (Cimino) or at the forearm (Gracz shunt). Factor concentrates were substituted as for intermediate size surgery. To prevent shunt occlusion, heparin (5 units/kg/h) was given during the first 3 days.

RESULTS

Indications for AVS creation were prophylaxis start (n = 20) and ITI (n = 7). Age at shunt insertion was median 1.5 years (minimum 8 months; maximum 11.7 years). Shunt maturation was achieved within a median of 3 weeks after surgery (1.5 weeks; 18 weeks). Age when home treatment was established was median 2.1 years (9 months; 11.7 years). Four patients required AVS revisions due to stenosis, but 26 of 27 patients (96%) achieved good long-term shunt function. There were few other complications.

CONCLUSION

Arteriovenous shunts provide a good alternative to CVAD and carry a lower risk of complications. AVSs allow earlier start of prophylaxis and home therapy with an improved quality of life for patients and families.

Recent advances in hemophilia B therapy

Hemophilia B is a hereditary bleeding disorder caused by the deficiency in coagulation factor IX. Understanding coagulation and the role of factor IX as well as patient population and diagnosis are all critical factors in developing treatment strategies and regimens for hemophilia B patients. Current treatment options rely on protein replacement therapy by intravenous injection, which have markedly improved patient lifespan and quality of life. However, issues with current options include lack of patient compliance due to needle-based administration, high expenses, and potential other complications (e.g., surgical procedures, inhibitor formation). As a result, these treatment options are also limited to developed countries. Recent advantages in hemophilia B treatment have focused on addressing these pain points. Emerging commercial products based on modified factor IX aim to reduce injection frequency. Exploratory research efforts have focused on novel drug delivery systems for orally administered treatment and gene therapy as a potential cure. Such alternative treatment methods are promising options for hemophilia B patients worldwide.

Systemic delivery of factor IX messenger RNA for protein replacement therapy

Safe and efficient delivery of messenger RNAs for protein replacement therapies offers great promise but remains challenging. In this report, we demonstrate systemic, in vivo, nonviral mRNA delivery through lipid nanoparticles (LNPs) to treat a Factor IX (FIX)-deficient mouse model of hemophilia B. Delivery of human FIX (hFIX) mRNA encapsulated in our LUNAR LNPs results in a rapid pulse of FIX protein (within 4-6 h) that remains stable for up to 4-6 d and is therapeutically effective, like the recombinant human factor IX protein (rhFIX) that is the current standard of care. Extensive cytokine and liver enzyme profiling showed that repeated administration of the mRNA-LUNAR complex does not cause any adverse innate or adaptive immune responses in immune-competent, hemophilic mice. The levels of hFIX protein that were produced also remained consistent during repeated administrations. These results suggest that delivery of long mRNAs is a viable therapeutic alternative for many clotting disorders and for other hepatic diseases where recombinant proteins may be unaffordable or unsuitable.

The past and future of haemophilia: diagnosis, treatments, and its complications

Haemophilia A and B are hereditary haemorrhagic disorders characterised by deficiency or dysfunction of coagulation protein factors VIII and IX, respectively. Recurrent joint and muscle bleeds lead to severe and progressive musculoskeletal damage. Existing treatment relies on replacement therapy with clotting factors, either at the time of bleeding (ie, on demand) or as part of a prophylactic schedule. The major complication of such therapy is the development of neutralising antibodies (ie, inhibitors), which is most frequent in haemophilia A. Treatment might improve considerably with the availability of new modified drugs, which might overcome existing prophylaxis limitations by reducing dosing frequency and thereby rendering therapy less distressing for the patient. Subcutaneous administration of some new therapies would also simplify prophylaxis in children with poor venous access. Gene therapy has the potential for a definitive cure, and important results have been obtained in haemophilia B. Despite improvements in haemophilia care, the availability of clotting factor concentrates for all affected individuals worldwide remains the biggest challenge.

Design of pH-Responsive Biomaterials to Enable the Oral Route of Hematological Factor IX

The oral administration of hematological factor IX (FIX) can offer a convenient prophylactic treatment for hemophilia B patients. pH-Responsive hydrogels based on poly(methacrylic acid)-grafted-poly(ethylene glycol) (P(MAA-g-EG)) have been engineered as delivery vehicles for FIX. In oral delivery, such hydrogel carriers protected FIX from the gastric environment and released it under intestinal conditions as demonstrated by evaluation of the loading and release of FIX. Tailoring of the hydrogel networks improved the loading of FIX within the microcarriers, which is critical for minimizing protein degradation. Optimizing the loading conditions by increasing the incubation time and using a reduced ionic strength buffer further improved the delivery potential of the microcarriers. The presence of the microcarriers significantly enhanced the oral absorption of FIX in vitro. As shown in this work, P(MAA-g-EG) microcarriers are promising candidates for the oral delivery of FIX.

Central venous access device (CVAD) complications in Haemophilia with inhibitors undergoing immune tolerance induction: Lessons from the international immune tolerance study

INTRODUCTION

Central venous access devices (CVADs) are frequently required as stable long-lasting venous access in children with haemophilia, especially those requiring immune tolerance induction (ITI) for inhibitors. CVAD infection is one of the most frequently reported catheter-related complications in this patient population.

AIM

Detailed review of CVAD complications from the International ITI (I-ITI) study and analysis of potential risk factors for such complications.

METHODS

Retrospective analysis of prospectively obtained data from the I-ITI study primarily focused on CVAD-related complications.

RESULTS

A total of 115 children were recruited and 183 CVADs were placed in 99 subjects resulting in 121,206 CVAD-days observed on-study. A total of 124 CVAD infections were reported in 41 of 99 (41%) subjects with an overall infection rate of 0.94 per 1000 CVAD-days (interquartile ranges 0-1.7). A similar number of infections were observed in the two treatment arms (median: 2 and 3 in high dose and low dose respectively). Infections occurred more frequently in the presence of external catheters than with fully implanted catheters (P = 0.026). Infected patients were significantly younger at the time of CVAD insertion (median age: 22 vs. 25 months, P = 0.020). Patients with Gram-positive infections were also significantly younger than those with Gram-negative infections (median age: 17 vs. 25 months, P < 0.0001).

CONCLUSION

CVAD infection was the most common complication observed in children with severe haemophilia and inhibitors in the frame of the I-ITI study. Younger age at CVAD insertion and external CVAD were associated with higher risk for infection. ITI outcome was unaffected by CVAD infections.

Current management of the hemophilic child: a demanding interlocutor. Quality of life and adequate cost-efficacy analysis

Hemophilias are the most known inherited bleeding disorders. The challenges in the management of hemophilic children are different from those in adults: prophylaxis regimen removed the hallmark of crippling disease with lifelong disabilities; individualized regimens are being implemented in order to overcome venous access problems. Presently, at least in high-income countries, advances in treatment of hemophilia resulted in continuous improvement of the patients' quality of life and life expectancy. Inhibitors remain the most severe complication of hemophilia therapy. The treatment' compliance is the key to achieve a successful management. The patient, his family, the medical and psychological team are the players of a comprehensive care system. The current management of hemophilic children is the example of huge resource investments enabling long-term benefits in particular quality of life as a primary objective of the healthcare process.

Renal diseases in haemophilic patients: pathogenesis and clinical management

Haemophilia A and B are genetic X-linked bleeding disorders, caused by mutations in genes encoding factors VIII and IX, respectively. Clinical manifestations of haemophilia are spontaneous haemorrhage or acute bleeding caused by minor trauma, resulting in severe functional consequences that can culminate in a debilitating arthropathy. Life expectancy and quality of life of patients with haemophilia have dramatically improved over the last years, mainly for new therapeutic options and the awareness to the risk of HCV and HIV infections. Different clinical problems arise from this important change in history of patients with haemophilia. In particular, ageing-related diseases, such as diabetes, hypertension and cancer, and chronic viral infections are emerging as new challenges in this patient population. Among the different types of chronic illnesses, renal diseases are of special interest as they involve some difficult management issues. In fact, decisions regarding adequate preventive strategies and viral infection treatment, the choice of the dialytic modality, placement of vascular access and prescription of dialytic treatments are particularly complicated, because only few data are available. In this review, we discuss the pathogenesis of renal damage in patients with haemophilia, especially in those with blood-transmitted viral infections, and the major issues about the management of renal diseases, including problems related to dialytic treatment and kidney transplantation, providing practical algorithms to guide the clinical decision-making process.

Issues in pediatric haemophilia care

The hemophilias are the most common X-linked inherited bleeding disorders. The challenges in children are different from that in adults and, If not properly managed, can lead to chronic disease and lifelong disabilities. Currently, inhibitors are the most severe complication and prophylaxis is emerging as the optimal preventive care strategy. Quality of life has become in the western countries the primary objective of the process of providing care, thus all the strategies (psychotherapy, physiotherapy, community life), not just the infusion of the missing factor, should be activated for the patient and family to give them the perception of being healthy.

Past, present and future of hemophilia: a narrative review

Over the past forty years the availability of coagulation factor replacement therapy has greatly contributed to the improved care of people with hemophilia. Following the blood-borne viral infections in the late 1970s and early 1980, caused by coagulation factor concentrates manufactured using non-virally inactivated pooled plasma, the need for safer treatment became crucial to the hemophilia community. The introduction of virus inactivated plasma-derived coagulation factors and then of recombinant products has revolutionized the care of these people. These therapeutic weapons have improved their quality of life and that of their families and permitted home treatment, i.e., factor replacement therapy at regular intervals in order to prevent both bleeding and the resultant joint damage (i.e. primary prophylaxis). Accordingly, a near normal lifestyle and life-expectancy have been achieved. The main current problem in hemophilia is the onset of alloantibodies inactivating the infused coagulation factor, even though immune tolerance regimens based on long-term daily injections of large dosages of coagulation factors are able to eradicate inhibitors in approximately two-thirds of affected patients. In addition availability of products that bypass the intrinsic coagulation defects have dramatically improved the management of this complication. The major challenges of current treatment regimens, such the short half life of hemophilia therapeutics with need for frequent intravenous injections, encourage the current efforts to produce coagulation factors with more prolonged bioavailability. Finally, intensive research is devoted to gene transfer therapy, the only way to ultimately obtain cure in hemophilia.

Modern haemophilia care

Haemophilia care has undergone substantial improvements during the past 40-50 years. Early clotting factor concentrates were not sufficiently refined to enable self-administered treatment at home until the 1970s. Unfortunately, these advances led to transmission of viral diseases including HIV and hepatitis, resulting in an increased burden of morbidity and mortality, especially during the 1980s. Throughout the past two decades, product development, including the advent of recombinant concentrates, has greatly improved the safety and availability of therapy and the focus of care is shifting towards prevention and management of disease sequelae. Long-term substitution therapy (prophylaxis) of the missing clotting factor is the recommended treatment in severe haemophilia, but several research issues remain to be elucidated such as when to start and how to optimise these regimens, and when or whether to stop this expensive treatment. The major side-effect of treatment, development of inhibitors to the infused concentrate, is the main threat to the health of patients and consequently the goal of intense research. Development of new products with improved pharmacokinetics is the next step to improved therapy.

Treatment of hemophilia: a review of current advances and ongoing issues

Replacement of the congenitally deficient factor VIII or IX through plasma-derived or recombinant concentrates is the mainstay of treatment for hemophilia. Concentrate infusions when hemorrhages occur typically in joint and muscles (on-demand treatment) is able to resolve bleeding, but does not prevent the progressive joint deterioration leading to crippling hemophilic arthropathy. Therefore, primary prophylaxis, ie, regular infusion of concentrates started after the first joint bleed and/or before the age of two years, is now recognized as first-line treatment in children with severe hemophilia. Secondary prophylaxis, whenever started, aims to avoid (or delay) the progression of arthropathy and improve patient quality of life. Interestingly, recent data suggest a role for early prophylaxis also in preventing development of inhibitors, the most serious complication of treatment in hemophilia, in which multiple genetic and environmental factors may be involved. Treatment of bleeds in patients with inhibitors requires bypassing agents (activated prothrombin complex concentrates, recombinant factor VIIa). However, eradication of inhibitors by induction of immune tolerance should be the first choice for patients with recent onset inhibitors. The wide availability of safe factor concentrates and programs for comprehensive care has now resulted in highly satisfactory treatment of hemophilia patients in developed countries. Unfortunately, this is not true for more than two-thirds of persons with hemophilia, who live in developing countries.

Venous access in haemophilic children: choice and management

Current haemophilia treatment in children is based on regular intravenous infusions of concentrates for prolonged periods, according to prophylaxis regimens or immune tolerance induction treatment, in cases of inhibitor development. Therefore, a stable and uncomplicated venous access is required and as such peripheral veins represent the preferred option. However, frequent infusions in the home setting can be problematic in very young children and for this reason, central venous access devices (CVADs) have been widely used to improve treatment feasibility. Unfortunately CVADs' use is associated with a high rate of complications, and infections and thrombotic occlusion can influence treatment outcome by causing unwanted treatment interruption. CVADs can be grouped into three main categories: external non-tunnelled, external tunnelled and fully implantable devices known as ports. The management of CVADs at home often represents a challenge because a strict adherence to sterile procedures is required. Indeed, the incidence of infections with ports is much lower than that reported for external devices; however, ports carry the inconvenience of needle sticks. More recently, arteriovenous fistula was shown to be a suitable alternative to CVADs because it is easy to use and is associated with a lower rate of complication.

Arteriovenous fistula as stable venous access in children with severe haemophilia

Treatment for children with severe haemophilia is based on prophylaxis and, if inhibitors occur, on immune tolerance induction (ITI). Both regimens require frequent infusions at early ages and therefore an adequate venous access is essential. Peripheral veins represent the best option; however, central venous catheters (CVCs) have been used to facilitate regular treatment. Unfortunately, survival of CVCs is affected by infectious and/or thrombotic complications that often lead to premature removal and consequent treatment discontinuation. This aspect may have an impact on treatment outcome, especially in the case of ITI. In light of this, internal arteriovenous fistula (AVF) has been proposed as an alternative option because of a lower rate of infectious complications. Moreover, AVF is easy to use in the home setting and is well accepted by children and parents. The possible complications are postoperative haematoma and transient symptoms of distal ischaemia; one case of symptomatic thrombosis has been reported to date. Other complications include loss of patency, aneurysmatic dilatation and limb dysmetria. A regular follow-up is mandatory to allow early remedial interventions. Surgical AVF dismantlement is recommended as soon as transition to peripheral vein access is possible.

Enabling normal psychophysical development in children with hemophilia: the choice for prophylaxis

Hemophilia A and B, the congenital deficiencies of coagulation factors VIII and IX, are characterized by recurrent joint and muscle bleeding episodes and progressive musculoskeletal damage (hemophilic arthropathy). Primary prophylaxis – that is, the regular infusion of factor concentrates after the first hemarthrosis and/or before 2 years of age – is now recognized as the first-choice treatment for children with severe hemophilia. Preventing bleeding from an early age enables avoidance of the clinical impact of hemophilic arthropathy and the consequences regarding psychosocial development and quality of life for these children. Interestingly, recent data suggest a role for early prophylaxis in also preventing inhibitor development, the most serious complication of treatment in hemophilia. Secondary prophylaxis, initiated after 2 years of age or after two or more joint bleeds, aims to avoid (or delay) the progression of arthropathy. In addition, better outcomes and better quality of life have been reported with earlier treatment. This review summarizes the evidence, current clinical strategies and open issues regarding prophylxis in children with hemophilia.