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ABSTRACT: Pediatric stroke is a rare but highly penetrant disease with a strong genetic background. While there is an increasing number of genome-wide association studies (GWAS) for stroke in adults, such studies for stroke of pediatric onset are lacking. Here we report the results of the first GWAS on pediatric stroke using a large cohort of 270 family-based trios. GWAS was performed using the Illumina 370 CNV SNP array and analyzed using the transmission disequilibrium test (TDT) as implemented in PLINK. An enrichment analysis was performed to identify additional true association signals among lower P- value signals, and searched for cumulatively associated genes within protein interaction data using dmGWAS. We observed clustering of association signals in four genes belonging to one family of metalloproteinases at high (ADAMTS12 P=2.9×10(-6), ADAMTS2 P=8.0×10(-6)) and moderate (ADAMTS13 P=9.3×10(-4), ADAMTS17 P=8.5×10(-4)) significance levels. Overrepresentation and gene-network analyzes highlight the importance of the extracellular matrix in conjunction with members of the phosphoinositide (PIP) and calcium signaling pathways in the susceptibility for pediatric stroke. Associated extracellular matrix components like ADAMTS proteins in combination with misbalanced coagulation signals as unveiled by gene network analysis suggest a major role of postnatal vascular injury with subsequent thrombus formation as the leading cause of pediatric stroke.
Blood 09/2012; · 9.90 Impact Factor
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ABSTRACT: OBJECTIVE: Previous studies in adults and mice have implicated ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13), also known as von Willebrand factor (VWF)-cleaving protease, as a protective factor for stroke. Here we investigated ADAMTS13 in 208 pediatric patients with arterial ischemic stroke (AIS) and 125 population-based control children in a frequency-matched case-control study. METHODS: The proportion of patients/controls with ADAMTS13 activity levels below and above the 10th percentile was compared. Additionally, in a quintile comparison, the proportion of patients versus controls in the lowest ADAMTS13 quintile was compared to those in the 2nd to 5th quintiles. Adjustment was performed for VWF antigen (VWF:Ag), factor VIII activity (FVIII:C), blood group, and age. RESULTS: Forty-six of 208 patients (22%) showed ADAMTS13 levels below the 10th percentile, compared with 5 of 125 controls (4%; p < 0.001). Odds ratios/95% confidence intervals were 7.30/2.73-19.50 for the lowest percentile and 2.44/1.15-5.16 in the quintile comparison after adjustment for VWF:Ag, FVIII:C, blood group, and age. Comparing the proportion of patients with ADAMTS13 activity below the 10th percentile within the different stroke subtypes (undetermined, cardioembolic, steno-occlusive arteriopathies), no statistically significant differences were found (undetermined, 16 of 89; cardioembolic, 6 of 40; steno-occlusive arteriopathies, 24 of 79; p = 0.08). ADAMTS13 levels did not significantly differ among stroke subtypes (p = 0.29). INTERPRETATION: Our findings implicate reduced ADAMTS13 activity as a risk factor for pediatric AIS, and support the concept that ADAMTS13 has a role in the pathogenesis of pediatric AIS. ANN NEUROL 2012.
Annals of Neurology 08/2012; · 11.09 Impact Factor
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ABSTRACT: Screening for inherited thrombophilia (IT) is controversial; persons at high risk for venous thromboembolism (VTE) who benefit from screening need to be identified. We tested 533 first- and second-degree relatives of 206 pediatric VTE patients for IT (antithrombin, protein C, protein S, factor V G1691A, factor II G20210A) and determined the incidence of symptomatic VTE relative to their IT status. The risk for VTE was significantly increased among family members with, versus without, IT (hazard ratio = 7.6; 95% confidence interval [CI], 4.0-14.5; P < .001) and highest among carriers of antithrombin, protein C, or protein S deficiency (hazard ratio = 25.7; 95% CI, 12.2-54.2; P < .001). Annual incidences of VTE were 2.82% (95% CI, 1.63%-4.80%) among family members found to be carriers of antithrombin, protein C, or protein S deficiency, 0.42% (0.12%-0.53%) for factor II G202010A, 0.25% (0.12%-0.53%) for factor V G1691A, and 0.10% (0.06%-0.17%) in relatives with no IT. Given the high absolute risk of VTE in relatives with protein C, protein S, and antithrombin deficiency, we suggest screening for these forms of hereditary thrombophilia in children with VTE and their relatives. Interventional studies are required to assess whether thromboembolism can be prevented in this high-risk population.
Blood 05/2012; 120(7):1510-5. · 9.90 Impact Factor
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ABSTRACT: Within the last two decades low molecular weight heparins (LMWH) have gained increasing widespread use as anticoagulants in children. The use of LMWH has been implemented into clinical care even though there is a lack of firm evidence on the efficacy and safety of LMWH in this population due to the absence of sufficiently powered randomized controlled trials. In the absence of clinical trials, we performed a meta-analysis of available single-arm studies using LMWH in children. A systematic search of electronic databases (Medline, EMBASE, OVID, Web of Science, The Cochrane Library) for studies published from 1980 to 2010 was conducted using keywords in combination both as MeSH terms and text words. Two authors independently screened citations and those meeting a priori defined inclusion criteria were retained. Data on year of publication, study design, country of origin, number of patients, ethnicity, venous thromboembolic events type, and frequency of recurrence and major bleedings were abstracted. Pooled incidence rates (IR) including 95% confidence intervals (95% CIs) on efficacy and safety data of LMWH administration on primary prophylaxis, as well as on secondary prophylaxis in children following symptomatic thromboembolism (TE) were shown. We included 2251 pediatric patients derived from 35 single-arm studies from 12 study countries who were eligible for analysis in the present systematic review. Pooled incidence rates (95% CI) to develop first TE on primary prophylaxis, further TE event on LMWH secondary prophylaxis, or a major bleeding event on LMWH were 0.047 (0.023 to 0.091), 0.052 (0.037 to 0.073) for efficacy, and 0.054 (0.039 to 0.074) for safety (treatment data only), respectively. Efficacy and safety data are comparable with adult data. The present systematic review suggests that use of LMWH in children as primary prophylaxis and in treatment of symptomatic thrombosis is effective and safe. However, properly designed randomized controlled trials are needed.
Seminars in Thrombosis and Hemostasis 10/2011; 37(7):814-25. · 4.52 Impact Factor
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ABSTRACT: In neonates and infants with idiopathic venous thrombosis (VTE) and in pediatric populations in which thromboses were associated with medical diseases, inherited thrombophilia (IT) have been described as risk factors. Follow-up data for VTE recurrence in neonates suggest a recurrence rate between 3% in provoked and 21% in idiopathic VTE. Apart from underlying medical conditions, recently reported systematic reviews on pediatric VTE have shown significant associations between factor V G1691A, factor II G20210A, and deficiencies of protein C, protein S and antithrombin, even more pronounced when combined IT were involved. Independent from the age at first VTE onset, the pooled odds ratios (OR: single IT) for VTE ranged from 2.4 for the factor II G20210A mutation to 9.4 in neonates and infants with antithrombin deficiency. The pooled OR for persistent antiphospholipid antibodies/lupus anticoagulants was 4.9 for pediatric patients with venous VTE. The factor II G20210A mutation (OR: 2.1), and deficiencies of protein C (OR: 2.4), S (OR: 3.1) and antithrombin (OR: 3.0) also played a significant role at recurrence. Based on these data, screening and treatment algorithms must be discussed.
Seminars in Fetal and Neonatal Medicine 08/2011; 16(6):345-8. · 3.91 Impact Factor
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ABSTRACT: Limited data are available on health-related quality of life (HR-QoL) in pediatric stroke survivors. The aim of the present study was to assess HR-QoL by self-assessment and parent/proxy-assessment in children and adolescents who survived a first stroke episode.
We investigated HR-QoL in pediatric stroke survivors (71 preschool children [G1] and 62 school children/adolescents [G2]) and in 169 healthy controls. HR-QoL was assessed in patients and parents/proxies with the generic KINDL-R questionnaire exploring overall well-being and 6 well-being subdimensions (physical, psychological, self-esteem, family-related, friend-related, and school-related). In pediatric stroke survivors the neurological long-term outcome was measured with the standardized Pediatric Stroke Outcome Measure.
Of stroke survivors, 65% exhibited at least 1 neurologic disability. Pediatric stroke survivors reported lower overall well-being compared with healthy controls. In G2 stroke patients, friend-related well-being respectively emotional well-being was significantly reduced compared with healthy controls (73.0 vs 85.0 points; p < 0.001 respectively 80.2 vs 84.5 points; p = 0.049). Parents/proxies of both stroke survivors rated the overall well-being and all subdimensions (except family-related and school-related well-being in G1 and G2 stroke survivors and physical functioning in G2 stroke survivors) lower compared with parents/proxies of healthy children/adolescents. Overall well-being was significantly reduced in children with moderate/severe neurological deficits compared with normal/mildly affected patients (75.5 vs 83.3 points, p = 0.01). Neonatal stroke survivors reported a significantly better neurological long-term outcome compared to childhood stroke survivors (82.0 vs 75.0 points; p = 0.005).
Pediatric stroke survivors compared with healthy controls are strongly affected regarding their overall well-being and older children/adolescents regarding their well-being with peers.
Annals of Neurology 01/2011; 70(1):70-8. · 11.09 Impact Factor
