[Pain therapy for children and adolescents with hemophilia : Recommendations by an expert panel]

BACKGROUND

Children and adolescents with severe hemophilia commonly suffer from acute and chronic pain as a consequence of hemophilia-related bleeding. Intervention-related pain also plays a major role. Despite its high prevalence in this patient group, hemophilia-related pain is not always adequately addressed and sufficiently treated.

OBJECTIVES

This paper discusses how to improve pain management for children and adolescents (0-18 years) with hemophilia and which specific features in this population should influence decisions in pain management.

MATERIALS AND METHODS

An expert panel discussed challenges in pain treatment in children and adolescents with hemophilia. Recommendations are based on evidence and clinical experience.

RESULT

Pain management in children with hemophilia needs improvement. Children with hemophilia are at risk of developing chronic pain and of suffering traumatization due to insufficient pain management. Pain therapy can be challenging in these children as both their age and the underlying disease limit the options in particular in pain medication. The expert panel developed recommendations to improve pain management in children with hemophilia.

Incidence of infective endocarditis and its thromboembolic complications in a pediatric population over 30years

BACKGROUND

Pediatric infective endocarditis (IE) has been associated with high morbidity and mortality, mostly related to thromboembolic complications (TEC). The objective of our study was to describe the experience in children with IE and to review the changes over a thirty-year period, regarding origin of IE, incidence of vegetations, TEC and their respective morbidity and mortality rates.

METHODS

A retrospective chart review of children aged 0-18years with IE defined by the Duke Criteria and admitted to The Hospital for Sick Children, was conducted. Data were divided into three periods (P); P1 (1979-1988); P2 (1989-1998); and P3 (1999-2008).

RESULTS

The study included 113 patients, median age 7yrs.; females: 46 (41%), congenital heart defects 95 (84%), comparable in all periods. Overall, cardiac vegetations were found in 68/113 patients (60%); large vegetations (≥1cm) in 32 patients (28%). Fourty-five (45/133 [40%]) TEC were documented, 22 patients (20%) developed cerebrovascular events (CVE) and 23 patients (20%) had non-CVE. Patients diagnosed during P3 were older, had more vegetations (p<0.05), and a higher incidence of community acquired-IE (p<0.05). Overall, mortality was 15%, comparable in all periods. Significant risk factors for mortality were vegetations (HR 6.44; 95% CI: 2.07-20.01, p=0.002) and heart failure (HR 28.39; 95% CI: 10.49-76.85, p<0.001).

CONCLUSIONS

Over the study period, we report a growing incidence of community acquired pediatric IE in older children accompanied by an increasing rate of TEC. Heart failure and vegetations were associated with an increased mortality. These preliminary data need to be confirmed by prospective data.

Anti-activated factor II assay for monitoring unfractionated heparin in children: results of the HEARTCAT study

Essentials Unfractionated heparin has variable effects in children and therefore, monitoring is essential. A randomized controlled trial substudy investigating an anti-IIa assay in children was conducted. Anti-IIa values are lower in younger children, an effect more pronounced at low-dose heparin. Heparin effect on Xa and IIa is not equal, particularly in infants and after high-dose heparin.

SUMMARY

Background Unfractionated heparin (UFH) is used for the prophylaxis and treatment of thrombosis in children. Laboratory monitoring of UFH is needed to prevent over-anticoagulation or under-anticoagulation. Objectives To investigate the association between UFH dose and UFH effect as monitored with the anti-activated factor II (FIIa) assay, the relationship between anti-FIIa and anti-activated factor X (FXa) effects, and the influence of patient age and other factors on UFH effect. Patients and methods This was a randomized controlled trial in children during cardiac catheterization, comparing high-dose UFH (100 units kg-1 bolus) with low-dose UFH (50 units kg-1 bolus). Blood samples were drawn at baseline, and after 30 min, 60 min, and 90 min. For the purpose of this study, 49 children and 117 blood samples were evaluated. Results The anti-FIIa assay discriminated well between high-dose and low-dose UFH. Multiple regression demonstrated significant influences of UFH dose and age on anti-FIIa levels. Younger children had lower anti-FIIa levels than older children, an effect that was more pronounced with low-dose UFH. Anti-FXa/anti-FIIa ratios were equal with low-dose UFH. However, anti-FXa levels were relatively increased over anti-FIIa levels in infants and after high-dose UFH bolus administration. Conclusion The UFH effect on anti-FIIa levels is lower in infants than in older children. This influence of age appears to be dose-dependent, being more pronounced with low-dose UFH. Anti-FXa and anti-FIIa levels are not equal, particularly in infants and after high-dose UFH. Monitoring UFH solely with anti-FXa assays may not be sufficient in children, and the anti-FIIa assay may provide important complementary information.

Exosomal particles secreted by prostate cancer cells are potent mRNA and protein vehicles for the interference of tumor and tumor environment

BACKGROUND

Remodeling of the tumor environment and the modulation of tumor associated non-malignant cells are essential events in tumor progression. Exosomes are small membranous vesicles of 50-150 nm in diameter, which are secreted into the extracellular space and supposedly serve as vehicles for signal and effector molecules to modulate adjacent target cells. We characterized the mRNA and protein composition as well as cellular functions of prostate cancer cell-derived exosomes.

METHODS

Exosomes were prepared from prostate cancer cell culture supernatant by ultracentrifugation and subsequently characterized by dynamic light scattering and electron microscopy. Exosomal mRNA and protein composition were analyzed by DNA microarrays and gel electrophoresis coupled with mass spectrometry. Physiological effects of exosomes were studied by means of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase release cell assays. Using a SILAC approach, putative uptake of exosomal human proteins in canine cells and canine de novo synthesis of proteins specified by exosome-transferred human mRNA was analyzed in MDCK cells via mass spectrometry.

RESULTS

Preparations of exosomes revealed typical cup shaped particles of 150 nm in diameter. Analysis of mRNA and protein composition of exosomes exhibited a wide range of mRNA and protein species. Interestingly, the packaging of at least small proteins into exosomes was apparently unspecific, as shown with the example of two model proteins. In cell culture incubation experiments exosomal preparations of prostate cancer cells caused anti-proliferative effects. MS analysis revealed the uptake of exosomal human proteins into canine cells after 6 hr of incubation.

CONCLUSIONS

The results reveal a distinct exosomal functionality in the modulation of the prostatic tumor adjacent environment. The multitude of translocated factors implies the induction of numerous effects in tumor-associated target cells, including impact on cellular growth.

No impact of endogenous prothrombotic conditions on the risk of central venous line-related thrombotic events in children: results of the KIDCAT study (KIDs with Catheter Associated Thrombosis)

BACKGROUND AND OBJECTIVE

Central venous lines (CVLs) are the major exogenous risk factor for deep venous thrombosis (DVT) in children. The study objective was to assess whether endogenous prothrombotic conditions contribute to the risk of CVL-related DVT in children.

METHODS

This was a cohort study of consecutive children with heart disease requiring CVLs for perioperative care. CVLs were inserted percutaneously in the upper venous system and patients received prophylaxis with continuous unfractionated heparin (50 u kg(-1)  d(-1) ). Blood samples to test for prothrombotic conditions were collected prospectively and assayed in a blinded fashion. Outcome assessment was by screening for DVT by venography, venous ultrasound and echocardiography.

RESULTS

The study population consisted of 90 children, median age 2.7 years (0 months-18 years). Prevalence rates of antithrombin deficiency, protein C deficiency, protein S deficiency, heterozygous factor V Leiden, prothrombin G20210A mutation, methylentetrahydrofolate C677TT genotype, hyperhomocysteinemia, lupus anticoagulant, anticardiolipin antibodies and increased levels of lipoprotein (a) were within the range reported for the general population. At least one prothrombotic condition was present in 38% of children and combined abnormalities in 8%. The incidence of DVT was 28% (25/90), and most DVTs were asymptomatic. None of the prothrombotic conditions showed a significant association with DVT. The population attributable risk (i.e. the risk of DVT in the overall population attributable to a specific condition) did not exceed 2.2%.

CONCLUSION

Prothrombotic conditions did not have an important impact on the risk of DVT in children with short-term CVLs. The results of the study suggest that screening for prothrombotic conditions is not justified in this setting.

Incidence of thrombotic and bleeding complications during cardiac catheterization in children: comparison of high-dose vs. low-dose heparin protocols

BACKGROUND

During cardiac catheterization (CC) in children, unfractionated heparin (UFH) is used for primary prophylaxis of thrombotic events (TE). However, the optimal UFH dose to minimize TE and bleeding in children has yet to be established.

OBJECTIVES

To (i) objectively assess the incidence of TE and bleeding during pediatric CC using clinical assessment and ultrasound; and (ii) compare a high-dose vs. low-dose UFH protocol for thromboprophylaxis.

METHODS

A randomized controlled trial (RCT) comparing high-dose UFH (100 units kg(-1) bolus, followed by 20 units kg h(-1) continuous infusion) vs. low-dose UFH (50 units kg(-1) bolus) during CC. Outcome assessment was by clinical examination and vascular ultrasound, performed by blinded examiners before and within 48 h after CC. Children with no consent for randomization were followed in a cohort receiving standard-of-care UFH (parallel-cohort RCT).

RESULTS

A total of 227 children were included; 137 were randomized and 90 followed in the cohort study. The overall incidence of TE was 4.6% and bleeding 6.6%. The RCT was stopped early for futility as there were no differences between the high-dose and the low-dose UFH in TE (5% vs. 3%; risk ratios [RR] 1.5, 95% confidence interval [CI] 0.3; 9) and bleeding (7% vs. 12%, RR 0.6, 95% CI 0.2; 2). There were also no differences when RCT and cohort study populations were combined.

CONCLUSIONS

The incidences of TE and bleeding during CC in children were low. There were no differences between the high-dose and the low-dose UFH protocols studied. Although Heparin Anticoagulation Randomized Trial in Cardiac Catheterization (HEARTCAT) was not designed as non-inferiority trial, low-dose UFH (50 units kg(-1) bolus) appears sufficient for thromboprophylaxis during CC.

Prevalence and genetic heterogeneity of SEN virus genotypes D and H in blood donors from Central and Western Europe and West Africa

OBJECTIVES

To establish prevalence and phylogenetic relationship of SEN virus (SENV) D and H in blood donors from Scotland, Czech Republic and Ghana.

AIM

To compare the data between three regions with differing prevalence of blood-borne viruses.

BACKGROUND

Anelloviruses are a ubiquitous group of viruses without a clear disease association. Although there is little evidence that they are pathogenic per se, they may have the ability to modify ongoing disease processes. They have a high degree of heterogeneity both within populations and across geographic regions.

MATERIALS AND METHODS

Three sets of donor samples were analysed by nested polymerase chain reaction (PCR) and hybridisation. A proportion of amplified samples were sequenced and phylogenetic analysis was carried out.

RESULTS

The prevalence figures (including mixed D + H infection) were established for SENV D: 1·0, 8·4 and 25·2% and H: 12·5, 34·8 and 61·0% in Scottish, Czech and Ghanaian blood donors, respectively. The compilation of prevalence figures indicates the changing ratio of SENV D/H in west-east direction, most obvious between Western Europe (D/H < 1) and far East Asia (D/H > 1). Phylogenetic analysis grouped the samples mostly in accordance with geographic origin, despite the variability of short sequence analysed. The previously indicated link between SENV prevalence and age was statistically significant in this study, only for SENV H in Czech samples.

CONCLUSION

SENV D and H appear to reflect the incidence of other blood-borne viruses in these locations. SENV H prevalence of 45·4% in Ghana represents the highest single-SENV-genotype prevalence described in blood donors to date.

Determinants of factor VIII plasma levels in carriers of haemophilia A and in control women

Factor VIII (FVIII) levels show a considerable variability in female carriers of haemophilia A. Presently, the reasons for this are poorly understood. The aim of the study was to elucidate the influence of genetic and non-genetic parameters on FVIII plasma levels in carriers (n = 42). Results were compared with age-matched healthy women without carriership of haemophilia A (n = 42). Each carrier was tested for the family-specific mutation, ABO blood group, FVIII level, von Willebrand factor (VWF) antigen and activity and C-reactive protein (CRP). FVIII levels were lower in carriers compared to non-carriers [74% (51-103) vs. 142% (109-169), P < 0.001]. No statistically significant differences were observed between the two groups with respect to VWF activity, prothrombin-time, hs-CRP, fibrinogen, body mass index (BMI), age and smoking status as well as the distribution of ABO blood groups. In non-carriers, FVIII was statistically significantly correlated with BMI, activated partial thromboplastin time (APTT), VWF antigen, hs-CRP and fibrinogen. In carriers, significant correlations between FVIII and APTT, VWF antigen and activity were found, whereas BMI, hs-CRP or fibrinogen did not correlate with FVIII. In non-carriers, the association of FVIII with ABO blood groups was statistically significant (P = 0.006), but not in carriers of haemophilia A (P = 0.234). The type of FVIII gene mutation did not influence FVIII levels. Carrier status is the major determinant of a carrier;s FVIII plasma level. Factors known to influence FVIII levels in the general population do not significantly affect FVIII activity in carriers, neither does the type of mutation influence FVIII levels.

Spontaneous disappearance of high titre factor VIII inhibitor 15 years after unsuccessful ITI

The most serious complication of haemophilia A is development of a high-titre factor VIII (FVIII) inhibitor which renders the patient unresponsive to FVIII replacement. Bleeding complications can only be controlled using FVIII-inhibitor bypassing agents but their effect is less certain. The ultimate goal is to eliminate the inhibitor by immune tolerance induction therapy (ITI) using daily high doses of FVIII. The success rate of ITI using various protocols is between 56 and 79% (1, 2). If ITI is unsuccessful, the inhibitor usually persists throughout life. We report on a patient with a high titre FVIII inhibitor that persisted after ITI but spontaneously disappeared 15 years later.

Spontaneous disappearance of high titre factor VIII inhibitor 15 years after unsuccessful ITI

The most serious complication of haemophilia A is development of a high-titre factor VIII (FVIII) inhibitor which renders the patient unresponsive to FVIII replacement. Bleeding complications can only be controlled using FVIII-inhibitor bypassing agents but their effect is less certain. The ultimate goal is to eliminate the inhibitor by immune tolerance induction therapy (ITI) using daily high doses of FVIII. The success rate of ITI using various protocols is between 56 and 79% (1, 2). If ITI is unsuccessful, the inhibitor usually persists throughout life.

We report on a patient with a high titre FVIII inhibitor that persisted after ITI but spontaneously disappeared 15 years later.

Salmonella serotypes isolated from pet chews in New Zealand

AIMS

To survey the prevalence of Salmonella in imported and domestic pet chews for assessing their potential in introducing novel pathogenic and antimicrobial resistant Salmonella serotype clones into New Zealand, and as vehicles of salmonellosis in the domestic home environment.

METHODS AND RESULTS

Three hundred samples, each of imported and domestic pet chews, were examined bacteriologically for the presence of Salmonella. Salmonella cells in the pre-enrichment culture were concentrated by using Dynabeads, and then selective enrichment and plating were performed by a method described in the Bacteriological and Analytical Manual, USFDA. Salmonella was isolated from 16 (5.3%) of the imported and 20 (6.7%) of the domestic pet chews, but the prevalences of Salmonella in imported and domestic products were not significantly different. All Salmonella isolates were serotyped and genotyped by pulsed-field gel electrophoresis and antimicrobial susceptibility determined by the Clinical and Laboratory Standards Institute disc diffusion methods. Salmonella Borreze has never been recorded earlier in New Zealand and was detected from Australian raw hide. Three isolates of Salmonella London were resistant to ampicillin and gentamicin, and two isolates of Salmonella Infantis were resistant to nalidixic acid, one of which was also resistant to streptomycin.

CONCLUSIONS

Novel pathogenic and antimicrobial-resistant Salmonella are being introduced into New Zealand through the import of pet chews. This indicates that pet chews are a potential source of exposure to Salmonella in the domestic home environment.

SIGNIFICANCE AND IMPACT OF THE STUDY

Contaminated pet chews are potential sources of Salmonella infection for domestic pets, and humans are at risk of exposure either directly by contact through handling or inadvertently by cross-contamination of food or food-contact surfaces in home environments.

Progression towards AIDS leads to increased torque teno virus and torque teno minivirus titers in tissues of HIV infected individuals

Torque teno virus (TTV) and Torque teno minivirus (TTMV) are highly prevalent in the general population and although no disease has been associated with these viruses yet, co-infections with other pathological viruses are frequent. Both viruses are extremely heterogeneous, especially for DNA viruses, and the role of the immune system in controlling the infections has yet to be established. In this study the TTV/TTMV viral loads in HIV positive tissues have been investigated for the first time. The titers of both TTV and TTMV were compared in the bone marrow and spleen tissues from three groups: HIV negative individuals, HIV positive individuals and HIV positive individuals who had progressed to AIDS, leading to immunosuppression. Limiting dilution PCR using primers situated in the UTR region of the genome were used to semi-quantitate the virus, and TTV and TTMV were differentiated using melting curve analysis of the PCR product. The AIDS group had significantly higher titers compared with both the HIV positive and negative groups for both bone marrow (AIDS vs. HIV positive P = 0.006, AIDS vs. HIV negative P < 0.001) and spleen (AIDS vs. HIV positive P = 0.022, AIDS vs. HIV negative P < 0.001). Analysis of TTV/TTMV titer with CD4 T lymphocyte count showed a significant inverse correlation however neither HCV co-infection or type of Anellovirus infection (single TTV or TTMV, or mixed TTV/TTMV) showed any significant correlation with virus titer. The results show a link between deterioration of the immune system and increased the viral loads in studied tissues.

Distribution of TT virus (TTV), TTV-like minivirus, and related viruses in humans and nonhuman primates

TT virus (TTV) and TTV-like minivirus (TLMV) are small DNA viruses with single-stranded, closed circular, antisense genomes infecting man. Despite their extreme sequence heterogeneity (>50%), a highly conserved region in the untranslated region (UTR) allows both viruses to be amplified by polymerase chain reaction (PCR). TTV/TLMV infection was detected in 88 of 100 human plasma samples; amplified sequences were differentiated into TTV and TLMV by analysis of melting profiles, showing that both viruses were similarly prevalent. PCR with UTR primers also detected frequent infection with TTV/TLMV-related viruses in a wide range of apes (chimpanzees, gorillas, orangutans, gibbons) and African monkey species (mangabeys, drills, mandrills). These findings support the hypothesis for the co-evolution of TTV-like viruses with their hosts over the period of primate speciation, potentially analogous to the evolution of primate herpesviruses.

Aerobic growth and survival of Campylobacter jejuni in food and stream water

When 40 Campylobacter jejuni isolates from human clinical cases, raw chicken and water were tested, 29 (72.5%) could be adapted to grow on nutrient agar under aerobic conditions. Once adapted, these isolates could grow on repeated aerobic subculture. An aerobically-grown Camp. jejuni isolate survived almost as well as the same isolate grown microaerophilically in sterile chicken mince at 5 degrees C, and survival of a cocktail of Camp. jejuni isolates under both atmospheres was comparable at 25 degrees C. However, at 37 degrees C, the decline in numbers of the aerobically-grown cells was greater. Survival of cells on chicken nuggets was poorer than in chicken mince. In filter-sterilized stream water incubated aerobically at 5 degrees C, survival of inocula grown under different atmospheres was again similar, but slightly better with the microaerophically-grown cells. Adaptation to aerobic growth was not found to enhance survival under aerobic conditions.