Impact of von Willebrand disease on health-related quality of life in a pediatric population

BACKGROUND

Von Willebrand disease (VWD) is the most frequent inherited bleeding disorder. Whether VWD is associated with health-related quality of life (HR-QoL) in children is unknown.

OBJECTIVES

This nationwide cross-sectional study measured HR-QoL in children with moderate or severe VWD. Our primary aim was to compare HR-QoL of VWD patients with that of reference populations. Additionally, we studied the impact of bleeding phenotype and VWD type on HR-QoL.

METHODS

HR-QoL was assessed with the Infant/Toddler QoL Questionnaire (0-5 years) and Child Health Questionnaire (6-15 years), and compared with reference population scores. Multivariate analysis was used to evaluate the influence of type of VWD and bleeding phenotype on HR-QoL scores.

RESULTS

Preschool children (0-5 years, n = 46) with VWD had lower HR-QoL scores for general health perceptions and parental time than reference populations. School children (6-15 years, n = 87) with VWD had lower scores for physical functioning, role functioning - emotional/behavioral, general health perceptions, and physical summary. Type of VWD was associated with HR-QoL in school children for bodily pain, general health perceptions, parental emotion, family activities, and physical summary. Scores of children with type 3 VWD were, on average, 15 points lower than those of the reference population on the above-mentioned scales. A more severe bleeding phenotype was associated with a lower score on 11/15 physical, emotional and social scales.

CONCLUSION

HR-QoL is lower in VWD children than in reference populations, in particular in school children. The negative impact of VWD is sensitive to type of VWD and bleeding phenotype; as well as physical scales, emotional and social scales are affected.

Health-related quality of life in preschool children in five health conditions

Objective

To test the responsiveness of the Infant/Toddler Quality of Life Questionnaire (ITQOL) to five health conditions. In addition, to evaluate the impact of the child’s age and gender on the ITQOL domain scores.

Methods

Observational study of 494 Dutch preschool-aged children with five clinical conditions and 410 healthy preschool children randomly sampled from the general population. The clinical conditions included neurofibromatosis type 1, wheezing illness, bronchiolitis, functional abdominal complaints, and burns. Health-related quality of life (HRQoL) was assessed by a mailed parent-completed ITQOL. Mean ITQOL scale scores for all conditions were compared with scores obtained from the reference sample. The effect of patient’s age and gender on ITQOL scores was assessed using multi-variable regression analysis.

Results

In all health conditions, substantially lower scores were found for several ITQOL scales. The conditions had a variable effect on the type of ITQOL domains and a different magnitude of effect. Scores for ‘physical functioning’, ‘bodily pain’, and ‘general health perceptions’ showed the greatest range. Parental impact scales were equally affected by all conditions. In addition to disease type, the child’s age and gender had an impact on HRQoL.

Conclusions

The five health conditions (each with a distinct clinical profile) affected the ITQOL scales differently. These results indicate that the ITQOL is sensitive to specific characteristics and symptom expression of the childhood health conditions investigated. This insight into the sensitivity of the ITQOL to health conditions with different symptom expression may help in the interpretation of HRQoL results in future applications.

Health-related quality of life among adult patients with moderate and severe von Willebrand disease

SUMMARY BACKGROUND

von Willebrand Disease (VWD) is the most frequent inherited bleeding disorder. It is unknown how this disorder affects quality of life.

OBJECTIVES

This nationwide multicenter cross-sectional study determined health-related quality of life (HR-QoL) in adult patients with moderate or severe VWD, and assessed whether bleeding severity and type of VWD are associated with HR-QoL.

METHODS

HR-QoL was assessed using the Short Form (SF)-36, and bleeding severity was measured using the Bleeding Score (BS).

RESULTS

Five hundred and nine patients participated; 192 males and 317 females, median age and range 45 (16-87) and 47 (16-84) years, respectively. Compared with the general population, HR-QoL in VWD patients was lower in the vitality domain (61 vs. 66 P < 0.001 for females, 67 vs. 72 P < 0.001 for males). Patients with the most severe bleeding phenotype (highest quartile BS, BS > 17) had a lower HR-QoL in eight domains than patients with a less severe bleeding type (lowest quartile BS, BS < 7) in the univariate analysis. After adjustment for age, gender, co-morbidity and employment/educational status, a more severe bleeding phenotype was associated with lower scores on the domains of physical functioning, role limitations due to physical functioning, bodily pain, general health, social functioning and physical component summary.

CONCLUSIONS

HR-QoL is lower in VWD patients compared with the general population. HR-QoL is strongly associated with bleeding phenotype.

Quantitative differentiation between healthy and disordered brain matter in patients with neurofibromatosis type I using diffusion tensor imaging

BACKGROUND AND PURPOSE

Hyperintensities on T2-weighted images are seen in the brains of most patients with neurofibromatosis type I (NF-1), but the origin of these unidentified bright objects (UBOs) remains obscure. In the current study, we examined the diffusion characteristics of brain tissue in children with NF-1 to test the hypothesis that a microstructural abnormality is present in NF-1.

MATERIALS AND METHODS

Diffusion tensor imaging (DTI) was performed in 50 children with NF-1 and 8 controls. Circular regions of interest were manually placed in 7 standardized locations in both hemispheres, including UBO sites. Apparent diffusion coefficients (ADC), fractional anisotropy (FA), and axial anisotropy (A(m)) were used to differentiate quantitatively between healthy and disordered brain matter. Differences in eigenvalues (lambda(1), lambda(2), lambda(3)) were determined to examine parenchymal integrity.

RESULTS

We found higher ADC values for UBOs than for normal-appearing sites (P < .01) and higher ADC values for normal-appearing sites than for controls (P < .04 in 5 of 7 regions). In most regions, we found no differences in FA or A(m). Eigenvalues lambda(2) and lambda(3) were higher at UBO sites than in normal-appearing sites (P < .04).

CONCLUSION

With ADC, it was possible to differentiate quantitatively between normal- and abnormal-appearing brain matter in NF-1 and also between normal-appearing brain matter in NF-1 and healthy brain matter in controls, indicating subtle pathologic damage disrupting the tissue microstructure in the NF-1 brain. Higher diffusivity for lambda(1), lambda(2), and lambda(3) indicates that this disturbance of microstructure is caused by accumulation of fluid or vacuolation.

[From gene to disease; neurofibromatosis type 1]

Neurofibromatosis type 1 (NF1) is an autosomal dominant disease characterised by café-au-lait spots, freckling in the axillary or inguinal region, dermal and plexiform neurofibromas and Lisch nodules. Complications are severe in one third of patients, and the clinical variability is pronounced, even within families. The NF1 gene has been localised to chromosome 17q11.2 and encodes the protein neurofibromin. The gene is proposed to be a tumour suppressor gene. Inactivation of neurofibromin leads to a disruption in cell growth regulation. Mutation analysis is possible but laborious, and therefore NF1 is generally a clinical diagnosis based on diagnostic criteria.

Functional mapping of anti-factor IX inhibitors developed in patients with severe hemophilia B

Development of inhibitory antibodies is a serious complication of treatment with repeated factor IX infusions in a minority of patients with hemophilia B. Such antibodies detected in 8 patients have been characterized. Typing studies revealed that patients' immune response toward factor IX is highly heterogeneous and involves immunoglobulin G (IgG) antibodies, preferentially IgG1 and IgG4. The preservation of the sequence and the 3-dimensional orientation of the amino acids constituting one epitope are highly important for the assembly of an antibody-antigen complex. To localize the epitopes on the factor IX molecule, an original approach was designed using a set of factor X chimeras carrying regions of factor IX. Results showed that some patients' antibodies were directed against both the domain containing the gamma-carboxy glutamic acid residues (Gla domain) and the protease domain of factor IX. In contrast, no binding was observed to the epidermal growth factor-like domains or to the activation peptide. Functional characterization showed that the purified IgG from patients' serum inhibited the factor VIIIa-dependent activation of factor X. Moreover, patients' IgG directed against the Gla domain inhibited the binding of factor IX to phospholipids as well as the binding of factor VIII light chain to factor IXa. These data demonstrate that inhibitors appearing in patients with severe hemophilia B display specificity against restricted functional domains of factor IX.

Deletions spanning the neurofibromatosis type 1 gene: implications for genotype-phenotype correlations in neurofibromatosis type 1?

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder characterized by abnormalities of tissues predominantly derived from the neural crest. Symptoms are highly variable and severity cannot be predicted, even within families. DNA of 84 unrelated patients with NF1, unselected for clinical features or severity, were screened with intragenic polymorphic repeat markers and by Southern analysis with cDNA probes. Deletions of the entire gene were detected in five patients from four unrelated families. Their phenotype resembled that of five previously reported patients with deletions, including intellectual impairment and dysmorphic features, but without an excessive number of dermal neurofibromas. This report supports the hypothesis that large deletions spanning the entire NF1 gene may lead to a specific phenotype.

Continuous infusion of recombinant factor VIIa in patients with haemophilia and inhibitors. Experience in The Netherlands and Belgium

BACKGROUND

Initial clinical experience with recombinant factor VIIa (rVIIa) for treatment of haemophilia patients with inhibitors against factor VIII or IX has been obtained by administration of rVIIa by repeated intravenous bolus injections. However, continuous infusion of rVIIa may be a more appropriate administration method if prolonged treatment is indicated.

METHODS

We have surveyed and analysed the initial experience with continuous infusion of rVIIa in the Netherlands and Belgium.

RESULTS

Five hospitals treated 7 haemophilia patients with inhibitors on 9 different occasions (4 bleedings, 5 surgical interventions) by continuous infusion of rVIIa over a total of 59 days. Haemostatic coverage was considered effective in 8 out of 9 cases and partially effective in 1 case. Continuous infusion of rVIIa was aimed at rVIIa target plasma levels of 10 U/ml and a decrease in prothrombin time (PT) of 3 s compared to control levels. This was obtained by an initial bolus injection of 90 micrograms/kg prior to continuous infusion of rVIIa at doses between 30-6 micrograms/kg/h (mean 17.5 micrograms/kg/h). A conventional one-stage factor VII coagulation assay, often used in combination with a PT, was satisfactory in monitoring rVIIa treatment. The additional clinical value of anti-fibrinolytic and anti-thrombophlebitic treatment was unclear.

CONCLUSION

In our experience, rVIIa appeared to be efficacious and safe when administered by continuous infusion. Continuous infusion of rVIIa is more convenient than bolus injections or rVIIa, easy to monitor and provides a cost reduction of > 50%. These advantages make continuous infusion an attractive administration method for prolonged treatment with rVIIa.

Minor disease features in neurofibromatosis type 1 (NF1) and their possible value in diagnosis of NF1 in children < or = 6 years and clinically suspected of having NF1. Neurofibromatosis team of Sophia Children's Hospital

OBJECTIVE

To establish the frequency of minor disease features in children with neurofibromatosis type 1 (NF1) and to evaluate the value of minor disease features in children < or = 6 years with a suspected diagnosis of NF1, considering that the disease is virtually 100% penetrant at 6 years of age.

DESIGN

During this 10 year, prospective, multidisciplinary, follow up study, 209 children suspected of having NF1 were examined; 150 were diagnosed with NF1 and 59 were not. The present analysis included children in whom NF1 was considered to be present at 6 years of age (n=85) and children without NF1 at 6 years of age (n=42).

RESULTS

The minor disease features macrocephaly (52.9%), short stature (24.7%), hypertelorism (63.5%), and thorax abnormalities (37.6%) were highly prevalent in children with NF1 and significantly associated with a diagnosis of NF1 at 6 years of age. In addition, the mean number of minor disease features was significantly higher in children with NF1 at 6 years of age compared to the group without a diagnosis at 6 years of age (mean 1.8 v 0.8, p<0.001). Moreover, children with three or more minor disease features were all diagnosed with NF1 under the age of 6 years. Multivariate analysis using a logistic regression model showed that macrocephaly, short stature, hypertelorism, and thorax abnormalities were all independently associated with the presence of NF1 at 6 years of age.

CONCLUSION

In children with insufficient diagnostic criteria aged < or = 6 years, documentation of minor disease features may be a helpful aid in predicting the diagnosis of NF1 in years to come.

A prospective 10 year follow up study of patients with neurofibromatosis type 1

OBJECTIVE

To establish the prevalence and incidence of symptoms and complications in children with neurofibromatosis type 1 (NF1) and to assess possible risk factors for the development of complications.

DESIGN

A 10 year prospective multidisciplinary follow up study.

PATIENTS

One hundred and fifty children diagnosed with NF1 according to criteria set by the National Institutes of Health.

RESULTS

In 62 of 150 children (41.3%) complications were present, including 42 (28.0%) children with one complication, 18 (12.0%) with two complications, and two (1.3%) with three complications (mean (SD) duration of follow up 4.9 (3.8) years). Ninety five of the 150 children presented without complications (follow up, 340.8 person-years). The incidence of complications was 2.4/100 person-years in this group. An association was found between behavioural problems and the presence of complications.

CONCLUSION

This is the largest single centre case series of NF1 affected children followed until 18 years of age. Children with NF1, including those initially presenting without complications, should have regular clinical examinations.

Endocrinologic disorders and optic pathway gliomas in children with neurofibromatosis type 1

OBJECTIVE

To establish the prevalence of endocrinologic disorders in children with neurofibromatosis type 1 (NF1) and the relationship between these disorders and cerebral abnormalities on magnetic resonance imaging.

DESIGN

A prospective follow-up study. Setting. A multidisciplinary neurofibromatosis clinic.

PATIENTS

A total of 122 children diagnosed with NF1 according to diagnostic criteria set by the National Institutes of Health.

RESULTS

Central precocious puberty (CPP) was diagnosed in 3 children and growth hormone deficiency (GHD) in 3 children. Optic pathway gliomas were observed in 15 children; in 9 of the 15 cases, the optic chiasm was involved. Of the 3 children with CPP, only 1 showed a chiasma glioma on magnetic resonance imaging. In 1 case with GHD, an optic chiasm glioma was detected on neuroimaging. Two of the 9 children with an optic chiasm glioma presented with CPP or GHD.

CONCLUSIONS

It has been suggested that CPP in children with NF1 is found exclusively in the presence of a chiasma glioma. We conclude that chiasma glioma may not be obligatory in children with NF1 and CPP or GHD. Moreover, we report a prevalence of GHD in children with NF1 of 2.5%, which has not been established earlier.

Diagnostic delay in neurofibromatosis type 1

Since 1985 a multidisciplinary team in the Sophia Children's University Hospital in Rotterdam provides diagnostic follow up and genetic counseling services for neurofibromatosis type 1 (NF1) patients and their families. Parents of 68 affected children as well as 24 affected parents were interviewed. Of the affected children, 50% and 33% of the affected adults were treated for symptoms related to NF1 before a specific diagnosis was made. Although the disease is fully penetrant by the age of 5 years, 35% of the affected children had not been diagnosed by this age. Parents stated a preference for early diagnosis of NF1. Diagnosis of NF1 did not seem to be a reason to refrain from having children. The general attitude towards prenatal diagnosis was positive; however few parents would actually terminate an affected pregnancy.

CONCLUSION

Overall delay in diagnosis of NF1 is significant. Knowledge of symptoms should make an early diagnosis possible with beneficial effects for the patient and family members.

[Neurofibromatosis in pediatrics]

The diagnostic criteria and complications of neurofibromatosis (Von Recklinghausen's neurofibromatosis or peripheral neurofibromatosis) are summarized. Patients and their relatives were studied in pediatric departments of the University Hospitals at Amsterdam (n = 23) and Rotterdam (n = 39) using a multidisciplinary approach and a standardized protocol. This comprehensive evaluation enables improved detection of serious complications and their management, and information to the parents about this highly variable disorder. Also, more insight is obtained into the natural history of the disease. Genetic counseling and family studies will become more precise in the near future, now the gene for NF I has been localised on chromosome 17, and for NF II (central NF) on chromosome 22, enabling DNA-marker studies.