Estimating the potential cost of a high dose immune tolerance induction (ITI) therapy relative to the cost of a combined therapy of a low dose ITI therapy with bypassing agent prophylaxis

INTRODUCTION

The International Immune Tolerance Study (I-ITI) demonstrated comparable success rates between low (FVIII 50 IU/kg/TIW) and high dose (FVIII 200 IU/kg/day) regimens. While costlier, the high dose ITI regimen achieved shorter time-to-treatment success with fewer bleeding episodes compared to the low dose ITI regimen. Adding bypassing agent prophylaxis (BAP) to a low dose ITI regimen may reduce bleeding while still being less costly than high dose ITI.

AIM AND METHODS

An economic model was developed to compare high dose ITI to low dose ITI with BAP. All model inputs were derived from clinical trials. The I-ITI study indicated a median time to negative inhibitor titre of 4.6 and 9.2 months and average number of bleeds/patient of 4.2 and 9.9 for the high and low dose regimens respectively. Based on the BAP trials, aPCC (85 U/kg/TIW) and rFVIIa (90 μg/kg/day) achieved a 62% and 45% reduction in bleeding frequency respectively. Cost analysis was from a US third party payer perspective and limited to drug costs. One-way, two-way and probabilistic sensitivity analyses were performed.

RESULTS

Costs of low dose ITI with aPCC prophylaxis until negative inhibitor titre is achieved was 24.0% less compared to high dose ITI. Low dose ITI with rFVIIa prophylaxis cost 46.5% more compared to high dose ITI. Model results were robust in the majority of the sensitivity analyses.

CONCLUSION

A low dose ITI regimen with aPCC prophylaxis may be cost saving compared to a high dose ITI regimen with the potential to reduce morbidity by lowering the risk for breakthrough bleeds.

Achievements, challenges and unmet needs for haemophilia patients with inhibitors: Report from a symposium in Paris, France on 20 November 2014

Over the past 20 years, there have been many advances in haemophilia treatment that have allowed patients to take greater control of their disease. However, the development of factor VIII (FVIII) inhibitors is the greatest complication of the disease and a challenge in the treatment of haemophilia making management of bleeding episodes difficult and surgical procedures very challenging. A meeting to discuss the unmet needs of haemophilia patients with inhibitors was held in Paris on 20 November 2014. Topics discussed were genetic and non-genetic risk factors for the development of inhibitors, immunological aspects of inhibitor development, FVIII products and inhibitor development, generation and functional properties of engineered antigen-specific T regulatory cells, suppression of immune responses to FVIII, prophylaxis in haemophilia patients with inhibitors, epitope mapping of FVIII inhibitors, current controversies in immune tolerance induction therapy, surgery in haemophilia patients with inhibitors and future perspectives for the treatment of haemophilia patients with inhibitors. A summary of the key points discussed is presented in this paper.

Women with congenital factor VII deficiency: clinical phenotype and treatment options from two international studies

INTRODUCTION

A paucity of data exists on the incidence, diagnosis and treatment of bleeding in women with inherited factor VII (FVII) deficiency.

AIM

Here we report results of a comprehensive analysis from two international registries of patients with inherited FVII deficiency, depicting the clinical picture of this disorder in women and describing any gender-related differences.

METHODS

A comprehensive analysis of two fully compatible, international registries of patients with inherited FVII deficiency (International Registry of Factor VII deficiency, IRF7; Seven Treatment Evaluation Registry, STER) was performed.

RESULTS

In our cohort (N = 449; 215 male, 234 female), the higher prevalence of mucocutaneous bleeds in females strongly predicted ensuing gynaecological bleeding (hazard ratio = 12.8, 95% CI 1.68-97.6, P = 0.014). Menorrhagia was the most prevalent type of bleeding (46.4% of patients), and was the presentation symptom in 12% of cases. Replacement therapies administered were also analysed. For surgical procedures (n = 50), a receiver operator characteristic analysis showed that the minimal first dose of rFVIIa to avoid postsurgical bleeding during the first 24 hours was 22 μg kg(-1) , and no less than two administrations. Prophylaxis was reported in 25 women with excellent or effective outcomes when performed with a total weekly rFVIIa dose of 90 μg kg(-1) (divided as three doses).

CONCLUSION

Women with FVII deficiency have a bleeding disorder mainly characterized by mucocutaneous bleeds, which predicts an increased risk of ensuing gynaecological bleeding. Systematic replacement therapy or long-term prophylaxis with rFVIIa may reduce the impact of menorrhagia on the reproductive system, iron loss and may avoid unnecessary hysterectomies.

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.

Clinical and laboratory characteristics of paediatric and adolescent index cases with venous thromboembolism and antithrombin deficiency. An observational multicentre cohort study

Venous thromboembolism [TE] is a multifactorial disease and antithrombin deficiency [ATD] constitutes a major risk factor. In the present study the prevalence of ATD and the clinical presentation at TE onset in a cohort of paediatric index cases are reported. In 319 unselected paediatric patients (0.1-18 years) from 313 families, recruited between July 1996 and December 2013, a comprehensive thrombophilia screening was performed along with recording of anamnestic data. 21 of 319 paediatric patients (6.6%), corresponding to 16 of 313 families (5.1%), were AT-deficient with confirmed underlying AT gene mutations. Mean age at first TE onset was 14 years (range 0.1 to 17). Thrombotic locations were renal veins (n=2), cerebral veins (n=5), deep veins (DVT) of the leg (n=9), DVT & pulmonary embolism (n=4) and pelvic veins (n=1). ATD co-occurred with the factor-V-Leiden mutation in one and the prothrombin G20210A mutation in two children. In 57.2% of patients a concomitant risk factor for TE was identified, whereas 42.8% of patients developed TE spontaneously. A second TE event within primarily healthy siblings occurred in three of 313 families and a third event among siblings was observed in one family. In an unselected cohort of paediatric patients with symptomatic TE, the prevalence of ATD adjusted for family status was 5.1%. Given its clinical implication for patients and family members, thrombophilia testing should be performed and the benefit of medical or educational interventions should be evaluated in this high risk population.

Antiphospholipid antibodies in neonates with stroke--a unique entity or variant of antiphospholipid syndrome?

OBJECTIVE

YB current affiliation: Department of Pediatrics, Hadassah-Hebrew University Medical Center, Mount Scopus, Israel YB and MJS contributed equally to the study and should be regarded as joint first authors on this manuscript. Antiphospholipid syndrome (APS) may present with thrombosis and persistently elevated titers of antiphospholipid antibodies (aPL) in the neonatal period. Our aim was to investigate the course and impact of elevated titers of aPL in a cohort of infants presenting with either perinatal arterial ischemic stroke (PAS) or cerebral sinus vein thrombosis (CSVT) during the perinatal period.

STUDY DESIGN

Sixty-two infants with clinically and radiologically confirmed PAS or CSVT presenting in the neonatal period underwent thrombophilia workup that included Factor V Leiden (FVL), PII20210A mutation, MTHFR 677T polymorphism, protein C, protein S, aPL namely either circulating lupus anticoagulant (CLA), anticardiolipin antibodies (aCL) or anti-β2-glycoprotein-1 (β2GP1). Mothers also underwent thrombophilia workup.

RESULTS

Twelve infants with persistently elevated aPL were prospectively followed. Infants with positive aPL showed no concordance with presence of maternal aPL. All children were followed for a median of 3.5 years (range: nine months to 19 years) with repeated aPL testing every three to six months. Anticoagulant therapy initiation and therapy duration varied at the physician's discretion. In 10/12 cases aPL decreased to normal range within 2.5 years; one female with complex thrombophilia risk factors required indefinite prolonged anticoagulation. None of the infants showed recurrent thrombosis or any other APS manifestations, despite lack of prolonged anticoagulation.

CONCLUSIONS

The presence of aPL may be important in the pathogenesis of cerebral thrombosis in neonates. Nevertheless, the nature of thrombophilia interactions in this period and their therapeutic impact warrants further investigation.

Developmental hemostasis: primary hemostasis and evaluation of platelet function in neonates

Hemostasis is a dynamic process and physiologic concentrations of coagulation proteins gradually increase with gestational age. Nevertheless, the risk for bleeding in term neonates is counterbalanced by the protective effects of physiologic deficiencies of the inhibitors of coagulation. Although laboratory diagnosis of coagulation disorders in infants may be difficult to establish, due to the need to adapt all assays for small amounts of blood and the age-related interpretation required for test results - evaluation of infants with secondary hemostatic defects is quite feasible, whereas laboratory assessment of primary hemostasis in neonates remains a challenge. While platelet number and volume are similar in neonates as compared to adult values, neonatal platelets certainly exhibit hyporesponsiveness. Analysis of platelet function may include aggregation studies or flow cytometry assays, using fluorescence-stained monoclonal antibodies against platelet membranes and cellular antigens. Data on platelet function in correlation with gestational age are scarce and the duration of platelet hyporeactivity and its clinical significance have not yet been completely elucidated. Whole-blood-based platelet function assays have shown in neonates as well as in premature infants progressive improvement of clot formation with gestational age. This article reviews platelet function, assessed by various techniques, and its development in the premature as well as healthy term neonate.

Standardization of thromboelastography: a report from the TEG-ROTEM working group

Laboratory evaluation of bleeding disorders has been performed with the standard clotting assays such as the PT and PTT for several decades. Our improved understanding of the process of blood coagulation has now revealed the important role played by the cellular elements such as platelets, monocytes and red blood cells. The need for a test that can assess clotting in a more 'global' manner, beyond the initiation of clot formation, has led to greater interest in assays such as thrombin generation and thromboelastography. Even though there are several publications using thromboelastography it remains a research tool as the methodology is not standardized. In an attempt to show reproducibility and consistency using thromboelastography, a group of investigators from different countries joined hands to form the TEG-ROTEM Working Group. Two studies were performed using PRP and FVIII deficient plasma and an intrinsic pathway activator. This article summarizes the results of the first international effort at standardization of thromboelastography. Both of the instruments using this technology (TEG(®) and ROTEM(®)) were used. Nine laboratories from countries around the globe participated in this effort. The results showed a significant inter-laboratory variance with CV's greater than 10%. Although these results were not satisfactory, this has been the first effort to standardize this methodology and significant work remains to be done to improve reliability and reproducibility. These studies were performed on PRP and the results may be more reliable when preformed on whole blood samples. We believe that it is important to continue this work so that we may investigate the usefulness and potential applications of thromboelastography in the evaluation of bleeding and thrombosis.

Bleeding disorders in neonates

SUMMARY

Bleeding disorders may present during the neonatal period, however, absent patient history along with unique physical signs, physiologically decreased levels of plasma proteins and laboratory variations of platelet function tests may render any diagnosis difficult to establish. Intra cranial haemorrhage (ICH) may be the clinical presenting symptom of a severe coagulation factor deficiency. Haemophilia in the newborn period poses unique challenges in diagnosis and management, Data presented from the UDC and similar surveillance systems world-wide can be used to further clinical research and improve management strategies. Development haemostasis should be considered as well as laboratory variations of coagulation tests while evaluating and diagnosis neonates suspected of bleeding disorders. Therapy of bleeding episodes in the neonate relies upon proper replacement and repeated haemostatic evaluation of patients' status, while dealing with underlying etiological causes. This manuscript discusses the unique aspects of clinical presentation, laboratory assessment, and treatment of various bleeding disorders in neonates.

Risk factors for central venous catheter thrombotic complications in children and adolescents with cancer

BACKGROUND

The use of central venous catheters (CVCs) has greatly improved the quality of care in children with cancer, yet these catheters may cause serious infectious and thrombotic complications. The aim of this prospective registry study was to assess the host and CVC-related risk factors for CVC-created thrombotic complications.

METHODS

Patients undergoing CVC insertion for chemotherapy were followed prospectively for CVC complications. At the time of enrollment, demographic, clinical, and CVC-related data, and family history of thrombosis were collected. Survival and Cox regression analyses were performed.

RESULTS

A total of 423 CVCs were inserted into 262 patients for a total of 76,540 catheter days. The incidence of CVC-related deep-vein thrombosis (DVT) was 0.13 per 1000 catheter-days (95% confidence interval [CI], 0.06-0.24). Insertion of peripherally inserted central catheters (PICCs) and insertion in an angiography suite significantly increased the risk of symptomatic CVC-related DVT. The incidence of CVC occlusion was 1.35 per 1000 catheter-days (95% CI, 1.1-1.63). Positive family history of thrombosis significantly increased the risk of CVC occlusion (hazard ratio [HR], 2.16; 95% CI, 1.2-3.8). The CVC-related risk factors were insertion of Hickman catheters, insertion in angiography suite, and proximal-tip location. Patients developing at least 1 episode of both CVC occlusion and infection had an increased risk for developing symptomatic CVC-related DVT (HR, 4.15; 95% CI, 1.2-14.4).

CONCLUSIONS

Both patient-related and CVC-related factors are associated with higher risk of symptomatic thrombotic complications. These risk factors could be used in the clinical setting and in developing future studies for CVC thromboprophylaxis.

Rate of inhibitor development in previously untreated hemophilia A patients treated with plasma-derived or recombinant factor VIII concentrates: a systematic review

BACKGROUND

Different rates of inhibitor development after either plasma-derived (pdFVIII) or recombinant (rFVIII) FVIII have been suggested. However, conflicting results are reported in the literature.

OBJECTIVES

To systematically review the incidence rates of inhibitor development in previously untreated patients (PUPs) with hemophilia A treated with either pdFVIII or rFVIII and to explore the influence of both study and patient characteristics.

METHODS

Summary incidence rates (95% confidence interval) from all included studies for both pdFVIII and rFVIII results were recalculated and pooled. Sensitivity analysis was used to investigate the effect of study design, severity of disease and inhibitor characteristics. Meta-regression and analysis-of-variance were used to investigate the effect of covariates (testing frequency, follow-up duration and intensity of treatment).

RESULTS

Two thousand and ninety-four patients (1965 treated with pdFVIII, 887 with rFVIII; median age, 9.6 months) from 24 studies were investigated and 420 patients were observed to develop inhibitors. Pooled incidence rate was 14.3% (10.4-19.4) for pdFVIII and 27.4% (23.6-31.5) for rFVIII; high responding inhibitor incidence rate was 9.3% (6.2-13.7) for pdFVIII and 17.4% (14.2-21.2) for rFVIII. In the multi-way anova study design, study period, testing frequency and median follow-up explained most of the variability, while the source of concentrate lost statistical significance. It was not possible to analyse the effect of intensity of treatment or trigger events such as surgery, and to completely exclude multiple reports of the same patient or changes of concentrate.

CONCLUSIONS

These findings underscore the need for randomized controlled trials to address whether or not the risk of inhibitor in PUPs with hemophilia A differs between rFVIII and pdFVIII.

Clot formation of neonates tested by thromboelastography correlates with gestational age

Evaluation of clot formation in neonates is troublesome. Our aim was to investigate cord blood clot formation of pre-term versus full-term infants and adults, using rotating thromboelastogram (ROTEM), Pentafarm, Munich, Germany). ROTEM was investigated in cord blood of 184 full-term and 47 pre-term infants. Measurements of the clotting time (CT), clot formation time (CFT) and maximal clot firmness (MCF) were obtained in order to asses reference values for this age group, and compare between full-term and pre-term neonates and compared to adult controls. For each infant demographic information and data regarding pregnancy and delivery were gathered. Infants were prospectively followed until discharge. CT and CFT were significantly shorter among pre-term and term infants as compared to adults [median CT: 185, 194, 293 seconds respectively, p pound0.001, CFT: 80, 76, 103 seconds respectively, p pound0.001). MCF was lower in pre-term and term as compared to adults (p pound0.001) with significantly lower values in pre-term as compared to full-term neonates (p=0.004). Clotting time and MCF correlated with gestational age (R=0.132, p=0.045, R= 0.259, p<0.001, respectively). No association was found between any ROTEM values and the occurrence of post-natal complications in infants of our study group. This is the first study assessing clot formation by ROTEM in pre-term infants. Clot formation parameters of term and premature infants correlated with gestational age. The predictive value of clot formation tests in neonates deserves further attention.

Influence of the factor II G20210A variant or the factor V G1691A mutation on symptomatic recurrent venous thromboembolism in children: an international multicenter cohort study

OBJECTIVE

To determine the relative importance of the factor (F) II G20210A or FV G1691A mutations as risk factors or predictors for fatal/non-fatal recurrent venous thromboembolism (VTE) in children.

METHODS

In the present cohort, the rate of VTE recurrence and the time to recurrence in relation to FII, FV, age, and sex was determined in consecutively enrolled patients with VTE aged newborn to

RESULTS

Of the 416 children enrolled, 44 had recurrent VTE at a median of 12 months following VTE onset. The overall incidence rate of recurrence was 19.8, 57.9 in patients with the FII variant, 17.9 for FV carriers, and 11.8 in the control cohort. When comparing FII patients, FV children and the control cohort multivariate analysis (Cox regression) adjusted for age and sex showed that the FII variant (hazard ratio 2.6; 95% confidence interval 1.1-5.9) influenced the hazard for recurrent VTE.

CONCLUSIONS

Based on multivariate analysis, the presence of the FII variant was associated with an increased risk of VTE recurrence.

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Key Words Collapse

MESH Headings

• Adolescent
• Age Factors
• Child
• Child, Preschool
• Cohort Studies
• Factor V/genetics
• Female
• Global Health
• Humans
• Infant
• Infant, Newborn
• Male
• Point Mutation
• Polymorphism, Single Nucleotide
• Prothrombin/genetics
• Recurrence
• Sex Factors
• Venous Thromboembolism/genetics

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Grants Collapse

Affiliation(s)

G Young Division of Hematology/Oncology, Children's Hospital Los Angeles, Los Angeles, CA, USA
S Becker
C Düring
F Friedrichs
N Goldenberg
G Kenet
M Manco-Johnson
C Scheffold
U Nowak-Göttl

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Perthes' disease and the search for genetic associations: collagen mutations, Gaucher's disease and thrombophilia

The role of heritable thrombophilic risk factors in the pathogenesis of the Perthes' disease is controversial. The clinical and radiological findings of Perthes' disease may be indistinguishable from those of Gaucher's disease, and the most common Jewish N370S Gaucher mutation is threefold greater in patients with Perthes' disease. Familial osteonecrosis of the femoral head is associated with variant mutations of collagen type II (COL2A1 mutations). We therefore studied the potential role of genetic thrombophilia and the Gaucher and COL2A1 mutations in children with Perthes' disease. Genomic DNA of 119 children with radiologically-confirmed Perthes' disease diagnosed between 1986 and 2005 was analysed for the thrombophilic polymorphisms Factor V Leiden, 677T-MTHFR and FIIG20210A. The results were compared with those of a group of 276 children without Perthes' disease. DNA was also analysed for the Gaucher mutations N370S, G insertion (84GG), L444P, Intron 2 (IVS2+1G>A) and R496H. Enzymic assays confirmed the Gaucher disease status. Collagen (COL2A1) mutations of the 12q13 gene were also analysed. The prevalence of thrombophilic markers was similar among the 119 patients with Perthes' disease and the 276 control subjects. The prevalence of the Gaucher mutation was consistent with Israeli population carriership data and did not confirm an earlier-claimed association with Perthes' disease. All 199 patients were negative for the studied COL2A1 mutations. We found no genetic association between Perthes' disease and either Gaucher's disease or COL2A1 mutations or increased genetic thrombophilia among our patients compared with the control group. A systematic review of case-control studies suggested that there was a positive association between Perthes' disease and Factor V Leiden. The impact of this association upon the disease, although not consistent across the studies, remains unclear.

Applicability and safety of recombinant activated factor VII to control non-haemophilic haemorrhage: investigational experience in 265 children

Experience of recombinant activated factor VII (rFVIIa, NovoSeven; Novo Nordisk A/S, Bagsvaerd, Denmark) to control haemorrhage in non-haemophilic children is limited. The object of this study was to examine the applicability and safety of rFVIIa amongst a group of non-haemophilic paediatric subjects. Details of all non-haemophilic children < or =16 years receiving rFVIIa whose data were recorded in the investigational, internet-based registry, haemostasis.com were analysed. A total of 265 children (mean age 7.7 years) were treated with rFVIIa; the median dose administered was 78.4 microg kg(-1) body weight (range 9.0-393.4) and the median total dose received 100.0 microg kg(-1) body weight (range 10.9-1341.2). Therapeutic areas included surgery (34.5%), coagulopathy (including thrombocytopenia; 29.0%), spontaneous bleeding (17.2%), trauma (8.4%) and intracranial haemorrhage (4.5%). Two patients experienced thromboembolic events following administration of rFVIIa. Thirty-nine patients died on account of haemorrhage or complications relating to their underlying condition; neither the thromboembolic events nor the deaths were related to rFVIIa administration. Bleeding stopped in 118/237 (49.8%), markedly decreased in 54/237 (22.8%), decreased in 51/237 (21.5%), remained unchanged in 13/237 (5.5%) and increased in 1/237 (0.4%) patients. These results suggest that rFVIIa is safe and widely applicable in children to control non-haemophilic haemorrhage.

Clinical trial: evaluation of a clinical decision-support model for upper abdominal complaints in primary-care practice

BACKGROUND

Gastro-oesophageal reflux disease (GERD) and dyspepsia affect 25-40% of the general population. In the absence of alarm symptoms, the current recommended policy in young dyspeptic patients is a 'test and treat' strategy for Helicobacter pylori; in GERD patients, a therapeutic trial with proton pump inhibitors is the treatment of choice.

AIM

To create a short and simple clinical algorithm, for the diagnosis and treatment of patients with upper gastrointestinal complaints.

METHODS

The clinical usefulness and cost-effectiveness of the new algorithm were evaluated in a controlled clinical trial, held in primary-care clinics in Israel. Clinical and economical treatment outcomes were evaluated after 1, 3 and 6 months comparing doctors who used the algorithm (cases) vs. those who did not (controls).

RESULTS

78 cases and 54 controls completed the 6 months of follow up. The improvement in symptom severity and quality of life was greater in the cases than in the controls (P < 0.05). General practitioner clinics visits (P = 0.04), gastroenterology clinics visits (P = 0.02) and medication costs (P = 0.004) were all significantly reduced among cases. Controls underwent also more imaging tests (computerized tomography, ultrasound and X-ray) and endoscopies. The average cost for 6 months' treatment and follow-up was $US 199 for cases compared with an average of $US 336 in the control group.

CONCLUSION

The use of a clinical decision-support tool can facilitate and promote the implementation of management guidelines by general practitioners. The short algorithm presented in the study was found to be useful and easy to apply in clinical practice. Its effectiveness can be further increased by implementing it in computerized medical systems.

Pharmacokinetics, efficacy, and safety of LMWHs in venous thrombosis and stroke in neonates, infants and children

Since the early nineties it has been shown that low molecular weight heparin (LMWH) has significant advantages over unfractionated heparin and oral anticoagulants for both the treatment and the prevention of thrombosis, not only in adults, but also in children. The present review was based on an 'EMBASE', 'Medline' and 'PubMed' search including literature published in any language since 1980 on LMWH in neonates, infants and children. It included paediatric pharmacokinetic studies, the use of LMWH in children with venous thrombosis, LMWH administration in paediatric patients with ischaemic stroke, and its use in order to prevent symptomatic thromboembolism in children at risk. An increasing rate of off-label use of LMWH in children has been reported, showing that LMWHs offer important benefits to children with symptomatic thromboembolic events and poor venous access. Two well-conducted pharmacokinetic studies in this age group showed that neonates and younger infants require higher LMWH doses than older children to achieve the targeted anti-Xa levels, due to an increased extra vascular clearance. Recurrent symptomatic thromboses under LMWH occur in approximately 4% of children treated for venous thrombosis, and in 7% of children treated for stroke; major bleed was documented in 3% of children with therapeutic target LMWH anti-Xa levels, whereas minor bleeding was reported in approximately 23% of children receiving either therapeutic or prophylactic doses, respectively. Further randomized controlled trials are recommended to evaluate the optimum duration and application for different LMWH indications in children.

Antiphospholipid syndrome and recurrent thrombosis in children

OBJECTIVE

Few studies have addressed antiphospholipid syndrome (APS) among children. Our aims were to analyze the clinical and laboratory manifestations in a pediatric APS cohort and to assess the influence of inherited thrombophilia factors on the outcome of children with APS.

METHODS

This was a multicenter study of children with APS who had no previous systemic autoimmune disease. We retrospectively reviewed their clinical and laboratory data, including hereditary thrombophilic deficits and outcomes.

RESULTS

The cohort comprised 28 patients (17 females, mean +/- SD age at onset 10.6 +/- 6.1 years). The most common initial manifestations of APS were venous thrombosis, stroke, and thrombocytopenia. Lupus anticoagulant was detected in 96% of those tested. After a mean +/- SD followup of 5.7 +/- 4.8 years, 16 children (57.1%) had central nervous system disease, 9 exhibited hematologic involvement, and 5 (all females) had systemic lupus erythematosus (SLE). None had renal, heart, or new skin disease. Seven of 24 patients exhibiting vascular thrombotic events had recurrences. Infants with perinatal stroke had monophasic disease, and other manifestations of APS did not develop later. Hereditary thrombophilia was more common in children who experienced a single episode of APS (8 [53.3%] of 15 patients) than in those who experienced recurrences (2 [28.6%] of 7 patients). However, only 2 patients in the latter group (28.6%) received anticoagulants after the first manifestation, compared with 12 (70.6%) of the 17 patients without recurrences.

CONCLUSION

APS in children has unique features. SLE may develop in a significant percentage of girls presenting with APS. Hereditary thrombophilia did not predict recurrent thrombosis, whereas the preventive impact of anticoagulant treatment following the first thrombotic event was noteworthy.

Non-invasive biomarkers of liver fibrosis in haemophilia patients with hepatitis C: can you avoid liver biopsy?

Liver biopsy remains the gold standard for the evaluation of fibrosis despite its risks and limitations, especially in haemophilia patients. Recently, non-invasive biomarkers have been used to assess histological features. The most thoroughly evaluated biomarker is the FibroTest (FT) (AUROC 0.80 for fibrosis stages F2F3F4 vs. F0F1). To estimate liver fibrosis in haemophilia patients infected with hepatitis C (HCV) using non-invasive biomarkers without liver biopsy. One hundred and thirty-two haemophilia patients (124 male, mean age 38 +/- 14 years) with anti-HCV antibodies were evaluated. These patients were stratified into several groups: patients with features of advanced liver disease - seven, persistently HCV RNA-negative - 21, persistently normal liver function tests (LFTs)- 24, HCV/HIV co-infected - 27. The following biomarkers of fibrosis were used: FT, AST-to-platelet ratio index (APRI), Forns index, age-platelet index and hyaluronic acid. The obtained scores were correlated with the clinical features of the patients. Estimated by the FT, the distribution of the stage of fibrosis in the 132 patients was F0F1 = 65% (86/132), F2 = 5% (7/132), F3 = 13% (17/132) and F4 = 17% (22/132). Using FT, all patients with clinical suspicion of advanced liver disease were classified as F3F4, whereas patients with persistently HCV RNA-negative were all classified as F0F1. Twenty-one per cent (5/24) of the patients with persistently normal LFTs had fibrosis stage F3F4. The proportion of F3F4 among HCV/HIV co-infected patients was significantly higher than among HCV mono-infected (52% vs. 33%; P = 0.05). Concordance of three or more biomarkers was present in 43% (57/132) of the patients. Liver biopsy could be avoided in 70% (92/132) using a practical assumption that if FT is in concordance with APRI and/or Forns, then we may confidently rely on the biomarker. Concordance rate for patients with presumably advanced or minimal liver disease was excellent (100% and 95% respectively). In our HCV-infected haemophilia patients, FT correctly identified clinically advanced or minimal liver disease. Discordance among the various biomarkers of fibrosis was considerate; nevertheless, practical combination of FT, APRI, and Forns may predict stage of fibrosis with accuracy, potentially avoiding liver biopsy in the majority of the patients.

Platelet function of newborns as tested by cone and plate(let) analyzer correlates with gestational Age

The issue of platelet function in infants and neonates is of interest, and current data are debatable. A new method for assessing platelet function involves using the cone and plate(let) analyzer (CPA), applicable for small (0.2 ml) whole blood volumes. We used polystyrene surface-coated plates to evaluate cord blood neonatal platelet function under flow. One hundred and sixty full-term and 29 preterm infants born at the Sheba Medical Center between March 2003 and January 2004 were evaluated for platelet adhesion measured as surface coverage (SC; the percentage of total area covered by platelets) and platelet aggregation, defined as the average size (AS) of the aggregates. Platelets from preterm infants displayed less platelet adhesion than did those from full-term infants. Platelet SC correlated with gestational age in all infants (p < 0.05), and both groups exhibited similar aggregation (AS). AS values, however, were significantly lower than the normal adult range in our laboratory. Infants born to mothers with pregnancy-induced hypertension displayed significantly lower SC. No association was found between CPA and postnatal complications.

CONCLUSION

CPA provides a rapid, feasible option for testing platelet function in neonates. Its potential predictive value deserves further attention, and more extensive studies are warranted.

Maternal selective serotonin reuptake inhibitor intake does not seem to affect neonatal platelet function tests

Recently, concerns have been raised regarding the potential impairment of neonatal platelet function and the potential risk of bleeding in neonates born to mothers treated with selective serotonin reuptake inhibitors (SSRI). Our aim was to test whether the platelet function of neonates born to SSRI-treated mothers was impaired when compared to non-SSRI-exposed neonates. In a single-center prospective study, platelet function was evaluated using a cone and platelet analyzer (CPA) device and compared between mother-infant pairs as well as normal non-SSRI-exposed infants. Twenty-seven SSRI-exposed and 27 non-SSRI-exposed full-term neonates and their 23 mothers were tested. No correlation was found between SSRI exposure among either neonates or mothers and parameters of surface coverage (SC) and average size (AS), manifesting platelet function as tested by CPA. SC was similar among SSRI-exposed babies as compared to those in the control group, whereas the size of platelet aggregates (AS) was higher among controls. Neither maternal diseases nor SSRI intake were associated with impaired platelet function and lower SC values, nor were any perinatal conditions. None of the babies suffered from bleeding. We conclude that maternal SSRI therapy does not impair whole-blood CPA-tested platelet function of healthy full-term neonates.

Hepatitis C at the Israeli National Hemophilia Center

Haemophilia patients who received non-virucidally treated large pool clotting factors before 1987 have a high rate of chronic hepatitis C viral infection (HCV). Some patients are coinfected with HIV. Haemophilia patients and other coagulation disorders were treated at one centre since the beginning of the 1970, and the Israeli National Hemophilia Center (INHC) was officially founded in 1987. To characterize patients with HCV as well as patients with HCV/HIV coinfection at the INHC. Patients with haemophilia and other coagulation disorders positive for HCV antibodies were evaluated between 2001 and 2004. Demographic data, type and severity of coagulation disorder, frequency of coagulation factor usage and treatment with concentrated clotting factors prior to 1987 were recorded. Liver enzymes, viral load, genotype and data supporting advanced liver disease were evaluated. About 179 of 239 haemophilia patients (75%) tested positive for anti-HCV antibodies. Our cohort consisted of 165 patients in whom clinical, biochemical and virological data were available. About 117 patients had active HCV infection with HCV-RNA-positive, and 27 were HCV/HIV coinfected. Twenty-one patients (13%) persistently tested HCV-RNA-negative, hence were considered to clear their HCV infection. There was no former USSR immigrants among HCV/HIV coinfected compared with HCV-infected or HCV-RNA-negative groups (0 vs. 30% and 38%, respectively; P < 0.001). HCV-RNA-negative patients used concentrated coagulation factor less frequently than HCV or HCV/HIV-infected patients (48% vs. 73%; P = 0.023, and 48% vs. 74%; P = 0.043, respectively). The use of concentrated clotting factors before 1987 was significantly more frequent in HCV/HIV than in either HCV-infected or HCV-RNA-negative patients (96% vs. 49% and 48%, respectively; P < 0.001). Compared with HCV/HIV subjects, patients with HCV monoinfection were characterized by a higher proportion of infection with genotype 1 (80% vs. 61%; P = 0.027). The rate of persistently normal liver enzymes in these patients was higher (24% vs. 7%; P = 0.05) than in the HCV/HIV-coinfected patients. Advanced liver disease was significantly more common in patients with HCV/HIV-coinfection than in HCV-monoinfected patients (11% vs. 3%; P = 0.045). The majority of haemophilia patients are infected with HCV. Viral clearance occurred in a minority of these patients. HCV monoinfected and HCV/HIV coinfected differ clinically and prognostically.

Bone properties and muscle strength of young haemophilia patients

PURPOSE

To evaluate bone properties, muscle strength and the relationship between the two, in young (7.0-17.7 years) haemophilia patients (h) and healthy boys (c).

SUBJECTS

Twenty-seven boys with severe haemophilia and 33 healthy boys, of similar age, body mass, height, (mean +/- sd for h and c, respectively: 11.2 +/- 3.2 vs. 11.4 +/- 2.9 years, 42.6 +/- 16.6 vs. 41.6 +/- 17.3 kg, 145 +/- 18 vs. 146 +/- 17 cm) and pubertal stage according to secondary sex characteristics, volunteered for the study. all subjects were physically inactive (as determined by questionnaire).

METHODS

Subjects performed isokinetic elbow and knee extension and flexion tests at two angular velocities (biodex system ii dynamometer). Bone properties were evaluated by qualitative ultrasound (sunlight omnisense), at the distal radius and tibial mid-shaft. H subjects received prophylactic factor viii treatment within the 24 h preceding testing. No test was performed in the presence of haemorrhage.

RESULTS

Muscle strength was consistently higher in c compared with h, especially in the lower limbs (e.g. knee extension: 1.80 +/- 0.44 vs 1.48 +/- 0.53 N x m x kg(-1) body mass, respectively, p = 0.01). No differences were observed in tibial or radial speed of sound between groups. Correlations between muscle strength and bone properties were observed only in the lower limbs and only in c (r = 0.37-0.48).

CONCLUSION

Muscle strength, especially lower limbs' strength, was lower in haemophilia patients compared with a matched, similarly inactive population of healthy boys. Nevertheless, at this age range, this relative weakness is not associated with inferior bone properties.

Recombinant factor VIIa: review of efficacy, dosing regimens and safety in patients with congenital and acquired factor VIII or IX inhibitors

Recombinant factor (rF)VIIa has been available to clinicians since 1996 and has an excellent safety record after almost three-quarters of a million doses have been administered. This paper will review the current clinical experience with rFVIIa dosing in acquired and congenital hemophilia with inhibitors and chronicle all spontaneous and clinical trial reports of thrombotic adverse events as of April 2003. Standard dosing of rFVIIa (90 micro g kg(-1)) allows binding of FVIIa to the surface of an activated platelet and can directly activate factor X in the absence of tissue factor. Experience with bolus dosing suggests that higher dosing (>200 micro g kg(-1)) may be more efficacious in treating hemophilia patients. Clinical trials are ongoing to validate this observation. Continuous infusion dosing may be efficacious for major surgery but high infusion rates (50 micro g kg(-1) h(-1)) might be needed. The relationship between dose of rFVIIa, amount of thrombin generated and measurable FVIIa level is still not known and perhaps newer testing which measures thrombin generation might be more advantageous. Relatively few thrombotic events have been associated with rFVIIa. Known factors predisposing to thrombosis were present in 20 of the 25 (80%) hemophilia patients who were reported spontaneously or who developed a thrombosis during a clinical trial. Additionally, thrombotic events have not increased despite a growing experience with higher dosing of rFVIIa.

The 1226G (N370S) Gaucher mutation among patients with Legg-Calve-Perthes disease

Legg-Calve-Perthes disease (LCPD) is an avascular necrosis of the femoral head with an annual incidence of 5-15/100,000. The estimated incidence of Gaucher disease, a lysosomal recessive storage disease, is 1:850, with a carrier rate of 1:17.5 for the 1226G (N370S) mutation among Ashkenazi Jews in whom there is a predilection. Since clinical and radiological findings of avascular hip necrosis due to either Gaucher disease or LCPD may be indistinguishable, misdiagnosis may occur. The purpose of this study was to evaluate the incidence of 1226G Gaucher mutation in a cohort of radiologically confirmed LCPD patients (diagnosed 1986-2000) in Israel. Enzyme assay was performed for confirmation of affected versus carrier status in patients with the 1226G mutation. In all, 78 LCPD patients, 86% males, 51% with severe bone disease, were studied. Family history was negative for Gaucher disease. Ethnic origin was 39% Ashkenazi Jewish, 6% Arab, and 55% other ethnicities. One Ashkenazi Jewish LCPD patient was homozygous for the 1226G mutation, and 4 LCPD patients were carriers: 3 Ashkenazi Jewish and 1 Arab patient. The frequency of the 1226G mutation among the LCPD patients was increased relative to historical Ashkenazi Jewish Israeli controls (P = 0.01). Since Gaucher disease may be misdiagnosed as LCPD, glucocerebrosidase enzyme testing is recommended among Ashkenazi Jewish children diagnosed with LCPD.

A new approach to treatment of bleeding episodes in young hemophilia patients: a single bolus megadose of recombinant activated factor VII (NovoSeven)

Recombinant activated factor VII (rFVIIa, NovoSeven) represents an effective treatment for hemophilia patients with inhibitors, but no consensus as to the best dosing regimen exists. We assessed the efficacy and safety of a rFVIIa 'megadose' (300 micro g kg(-1) bolus) as treatment for bleeds in three young inhibitor patients. Of 114 bleeds, 95 responded to a single dose. Pain relief was faster and therapy duration significantly shorter than with continuous infusion (CI) regimens or standard boluses (90 micro g kg(-1) every 3 h). Rebleeding occurred in 9.6% of cases and 19/114 episodes required a second bolus injection. Although rFVIIa consumption per bleed (median: 300 micro g kg(-1)) was higher than with standard boluses (180-270 micro g kg(-1)), patients found single bolus administration more convenient than recurrent injections or CI. With two exceptions, no complications occurred within 3 h of treatment, despite high FVII:C levels (median: 27.4 U mL(-1); range: 19.8-54 U mL(-1)). Treatment of bleeds with a rFVIIa megadose in young inhibitor patients is effective and well tolerated.

Efficacy and safety of a factor VIII-von Willebrand factor concentrate 8Y: stability, bacteriological safety, pharmacokinetic analysis and clinical experience

The present study was undertaken to evaluate stability, pharmacokinetic profile and efficacy of continuous infusion of 8Y in patients with different types of von Willebrand disease (vWD). Following reconstitution, 8Y levels of von Willebrand factor ristocetin cofactor (vWF:Rco), vWF antigen and factor VIII coagulant activity (FVIII:C) decreased to about 80% of the baseline levels; addition of low molecular weight heparin decreased the level of FVIII:C even further. Reconstituted 8Y was found to be sterile for up to 6 days postreconstitution. Ten vWD patients (four with type 2A, three with type 3, two with type 1 and one with 2N) underwent pharmacokinetic analysis. The recovery of vWF: RCo was significantly lower in patients with type 3 vWD (1.4 +/- 0.05% U(-1) kg(-1)) compared with that of the patients with types 1 (2.3 +/- 0.52% U(-1) kg(-1)) or 2A (2.0 +/- 0.06% U(-1) kg(-1)) vWD (P = 0.015). Type 3 vWD patients exhibited significantly higher vWF:RCo clearance (5.1 +/- 1.1 mL kg(-1) h(-1)) compared with that of patients with type 2A (2.8 +/- 0.7 mL kg(-1) h(-1)) and type 1 (2.6 +/- 1.0 mL kg(-1) h(-1)) vWD (P = 0.028). Accordingly, terminal half-life was lower in patients with type 3 vWD (8.0 +/- 0.6 h(-1)) compared with type 2A (12.7 +/- 5.9 h(-1)) or type 1 (14 +/- 1.2 h(-1)) vWD patients. Multimeric pattern of vWF from patients' plasma was similar to that of 8Y. In two patients treated with 8Y by continuous infusion for prevention or treatment of bleeding haemostasis was achieved. Thus, 8Y is suitable and haemostatically effective for continuous infusion treatment in patients with vWD.

The impact of chronic disease on the family

Haemophilia is a chronic disease, affecting patients and their families. The impact of such a disease upon each family is dependent upon family type and characteristics and adjustment to it varies with time, in concordance with the family's lifecycle. In the National Hemophilia Center in Israel we lead a special support system and conduct group therapy from the very early stage of haemophilia diagnosis throughout the lifetime of patients. The general definitions of a family's lifecycle, the effect of the disease and the required adjustment to it are described in this paper. We refer to special difficulties associated with haemophilia as a chronic, genetic disease and describe ways to cope, discussing the support systems that have been established in our centre.

Amelioration of experimental colitis by thalidomide

BACKGROUND

Rectal administration of iodoacetamide induces colitis by blocking sulphhydryl groups and generating inflammatory mediators. Thalidomide, a non-barbiturate hypnotic, also has an anti-inflammatory effect, presumably by suppressing the production of tumor necrosis factor alpha. In patients with Crohn's disease, neutralization or suppression of TNF alpha reduces inflammation.

OBJECTIVES

To evaluate the effects of thalidomide in a model of experimental colitis.

METHODS

Colitis was induced in rats by intracolonic administration of 3% iodoacetamide. In the treatment group, thalidomide 50 mg/kg was given daily by gavage and continued for 7 days until the rats were sacrificed. Their colons were then processed for wet weight, lesion area, weight of mucosal scraping, myeloperoxidase activity and histology. Serum levels of TNF were determined.

RESULTS

Colonic wet weight, lesion area, myeloperoxidase activity and serum levels of TNF alpha were significantly lower (P < 0.05) in the treatment group (iodoacetamide + thalidomide) than the control group (iodoacetamide only). Histologically, colonic inflammation in the treated group was markedly decreased.

CONCLUSIONS

Thalidomide effectively decreases colitis induced by iodoacetamide. The mechanism is probably associated with inhibition of TNF alpha, and should be further studied.

Recombinant activated factor VII for adjunctive hemorrhage control in trauma

BACKGROUND

Recombinant activated factor VII (rFVIIa) was approved for treatment of hemorrhages in patients with hemophilia who develop inhibitors to factors VIII or IX. Conditions with increased thromboembolic risk, including trauma with or without disseminated intravascular coagulation, were considered a contraindication for the drug. The mechanism of action of rFVIIa suggests enhancement of hemostasis limited to the site of injury without systemic activation of the coagulation cascade. Therefore, use of the drug in trauma patients suffering uncontrolled hemorrhage appears to be rational.

METHODS

Seven massively bleeding, multitransfused (median, 40 units [range, 25-49 units] of packed cells), coagulopathic trauma patients were treated with rFVIIa (median, 120 microg/kg [range, 120-212 microg/kg]) after failure of conventional measures to achieve hemostasis.

RESULTS

Administration of rFVIIa resulted in cessation of the diffuse bleed, with significant decrease of blood requirements to 2 units (range, 1-2 units) of packed cells (p < 0.05); shortening of prothrombin time and activated partial thromboplastin time from 24 seconds (range, 20-31.8 seconds) to 10.1 seconds (range, 8-12 seconds) (p < 0.005) and 79 seconds (range, 46-110 seconds) to 41 seconds (range, 28-46 seconds) (p < 0.05), respectively; and an increase of FVII level from 0.7 IU/mL (range, 0.7-0.92 IU/mL) to 23.7 IU/mL (range, 18-44 IU/mL) (p < 0.05). Three of the seven patients died of reasons other than bleeding or thromboembolism.

CONCLUSION

The results of this report suggest that in trauma patients rFVIIa may play a role as an adjunctive hemostatic measure, in addition to surgical hemostatic techniques, and provides the motivation for controlled animal and clinical trials.

Successful pregnancy after high-dose cyclophosphamide and ifosfamide treatment in two postpubertal women

Alkylating agents, especially cyclophosphamide, are known to have a destructive effect on the ovaries and to result in sterility in many young women treated with these drugs. This is especially true when the treatment is given to postpubertal women. The authors describe 2 postpubertal women aged 16 and 25 suffering from Ewing sarcoma who were treated with the very aggressive Sloan-Kettering protocol, which includes high-dose cyclophosphamide and ifosfamide in addition to other drugs. Both women had spontaneous pregnancies and delivered normal babies. The significance of these cases in view of the experimental various reproductive preservation measures offered to such women is discussed.