Coagulation testing in the evaluation of suspected child abuse

Every year in Germany nearly 3000 cases of child abuse were reported. When children are presented at emergency units with suspicious injuries and bruises a detailed documentation an evaluation is necessary after emergency treatment. As differential diagnosis inherited or acquired bleeding disorders should be excluded. In addition to a detailed evaluation of personal and family history and a physical evaluation different coagulation test to exclude defects of primary and secondary hemostasis should be performed. Clinician must know the limitations of these tests and keep in mind that an abnormal coagulation test does not exclude child abuse. Coagulation defects may be the consequence of child abuse and neglect or the two conditions may coexist.

Thrombophilia in the young

Venous thromboembolism (VTE) is a rare disease that is being increasingly diagnosed and recognized in paediatrics in the past decade, usually as a secondary complication of primary severe underlying diseases. Apart from acquired thrombophilic risk factors, such as lupus anticoagulants, inherited thrombophilias (IT) have been established as risk factors for venous thromboembolic events in adults. In children with idiopathic VTE and in paediatric populations in which thromboses were associated with underlying medical diseases, IT have been described as additional prothrombotic risk factors. Follow-up data for VTE recurrence in children are available and suggest a recurrence rate of approximately 3% in neonates and 8% in other children. Here we present a review of the impact of IT on early onset of VTE and recurrence in children. Statistically significant associations between the IT traits investigated, e.g. factor V G1691A, factor II G20210A, protein C-, protein S-, antithrombin deficiency, elevated lipoprotein (a), combined IT and VTE onset were reported. In addition, statistically significant associations with recurrent VTE were calculated for protein S-, antithrombin-deficiency, and the factor II variant and combined IT. The absolute risk increase for VTE recurrence associated with IT ranged from 9.8 % for children carrying the factorII variant to 26% and 29% in children with combined IT and protein S-deficiency, respectively. Data obtained gave evidence that the detection of IT is clinically meaningful in children with VTE and underlines the importance of a paediatric thrombophilia screening program. Based on these data treatment algorithms have to be discussed.

Repeated coagulation testing in children

Background Mild bleeding disorders (BD) such as von Willebrand disease (VWD) type I are often difficult to diagnose because of inconclusive laboratory results. Our study examines the diagnostic value of repeated testing.

Patients, methods Prospective study on 200 children. Extensive laboratory testing was done twice and a standardized history was taken.

Results 165 patients completed the study (median age 5.6 years). Main reason for referral was aPTT prolongation (n = 109). The initial diagnosis was upheld in 74/165 (44.8%) children. Of 18 patients rated normal, 8 had to be reclassified as possible VWD later. Ten patients were diagnosed VWD I. In 36 patients possible VWD was found, 13 of these had normal results at the second visit while in 6 VWD became more likely. The main diagnosis was lupus-anticoagulant (n=79), normalizing in 24. A total of 88 children underwent surgery during the study period.

Conclusion Our study shows frequent changes in the diagnosis and highlights the limitations of single laboratory tests in detecting mild BD. Clinical and laboratory abnormalities have to be followed and tests must be repeated in unclear cases. Normal values at one point do not exclude a BD.

Arterial thrombosis in homozygous antithrombin deficiency

Antithrombin (AT), a serin protease inhibitor (serpin) produced in the liver, inhibits mainly thrombin and factor Xa. Antithrombin deficiency (AD) is associated with a higher incidence of thrombosis. Case report: We report a newborn with uncomplicated birth in the 40+5 week of gestation and postnatal appearance of a reticular, livide haematoma on the right upper arm and a tonic clonic epileptic seizure. Clinical examination revealed weak pulses in the A. radialis and ulnaris. MRI scan showed a large thrombus in the A. carotis interna and externa with large cerebral infarction and a thrombus in the A. subclavia. Laboratory work up showed elevated D-dimers and antithrombin levels < 20% (lowest 15%), age-related values for protein C, protein S, plasminogen, and no other inherited thrombophilia. Therapy: We started anticoagulation with unfractionated heparin intravenously (aPTT: 50–60 s) and under suspicion of an AD the substitution of AT (70 U/kg body weight). In course of time we changed anticoagulation to low molecular weight heparin (Anti Xa 0.6–0.8 U/ml) and substitution of 250 E/kg AT every second day. In the molecular work up we found a homozygous missense mutation in exon 2 of SERPINC1 gene (type „Budapest 3”). Molecular analysis showed also heterozygous mutations in both parents and a homozygous mutation in the asymptomatic brother aged three years. At age of six months we changed the anticoagulation to coumadin (INR 2.5–3.5). Anticoagulation with coumadin was also started in the brother. Discussion: Hereditary AD is associated with an increased risk of thrombosis. The homozygous status mainly leads to intrauterine fetal loss or the occurrence of peri- and postnatal thrombosis. Therapy consists in the substitution of AT and a lifelong anticoagulation with vitamin K antagonists also in asymptomatic patients.

Climbing therapy under PK-tailored prophylaxis

Climbing has a low risk of injury and strengthens the entire musculature. Due to its benefits in physical and mental health as well as its high fun factor climbing is an established way of therapy. So far, the usefulness of climbing therapy has not been shown for people with haemophilia (PWH). A crucial requirement for physical activity in PWH is regular prophylaxis. As the patient’s individual pharmacokinetic (PK) response varies significantly, PK-tailored prophylaxis may decrease bleeding frequency. Case report: We describe a man (age 25 years) with severe haemophilia A who took part in an 8.5-month weekly climbing program under PK-tailored prophylaxis. Bleeding frequency, factor consumption, joint health (Haemophilia Joint Health Score, HJHS), quality of life (Haemo-QoL-A) and climbing performance (UIAA scale) were assessed before and after the training. Prior to the study, the patient was on demand treatment. The patient was started on standard prophylaxis for a 2 months period and then observed for 6.5 months under PK-tailored prophylaxis. PK-tailored prophylaxis was targeted to a trough level of 1–3%. For high-impact activities a factor activity >15%, for low-impact activities a factor activity >5% was suggested. Results: Climbing therapy was safe. The bleeding rate decreased from 14 (2012) to 1 (during the study period of 8.5 months). The one bleeding event was due to a missed infusion and was not triggered by physical activity. The elimination half-life using Bayesian statistics was determined to be 16h. Using this half-life for PK-tailored prophylaxis reduced the factor VIII consumption in comparison to standard prophylaxis. Joint health was particularly improved in the categories range of motion and swelling. Quality of life scores stayed at a high level. Climbing performance improved by 1 grade. Conclusio: The combination of PK-tailored prophylaxis with therapeutic climbing improved clinical outcome in this young adult with severe haemophilia. The tailored concept for high- and low-impact activities appeared to be safe.

Postoperative bleeding in paediatric ENT surgery

Bleeding after ear-nose-and throat surgery in children is a serious complication. With the help of the German Surveillance Unit for Rare Paediatric Disorders (Erhebungseinheit für seltene pädiatrische Erkrankungen in Deutschland; ESPED) a two year survey was performed to record the incidence, severity, reasons and treatment of haemorrhages. During the study period, 1069 bleeds were reported from 720 paediatric hospitals and departments of otorhinolaryngology after adenoidectomy and tonsillectomy. 713 reports could be analyzed. Two deaths occurred after adenoidectomy. Although laboratory screening was performed in more than 70% of all cases, bleeding complications were neither foreseeable nor preventable. Inherited coagulopathies were rare and in most cases not detected, neither by laboratory screening nor by taking a history. Since preoperative measures cannot help much to improve the situation, all efforts have to be taken to improve the postoperative period, especially since more than 20% of the hemorrhages occurred during weekends. Guidelines on postoperative care and behaviour should therefore be implemented and parents and patients must be informed on bleeding risks and on what to do in case of emergency. If bleeding occurs, extensive coagulation testing is mandatory.

Haemophilia and thrombophilia

For the study presented here 135 pediatric PUP patients with haemophilia consecutively admitted to German pediatric haemophilia treatment centers were investigated. In addition to factor VIII activity, the factor V (FV) G1691A mutation, the factor II (FII) G20210A variant, methylenetetrahydrofolate reductase (MTHFR) T677T genotype, elevated lipoprotein a (Lp a), antithrombin, protein C, and protein S were investigated. 103 out of 122 HA patients (FVIII activity <1%) were suffering from severe HA. The prevalence of prothrombotic risk factors in children with severe haemophilia A (HA) did not differ from previously reported data: FV GA 5.8%, FII GA 3.9%, MTHFR TT 10%, elevated Lp a 7%, protein C type I deficiency 1.1%. The first symptomatic bleeding leading to diagnosis of severe haemophilia occurred with a median age of 1.6 years (range: 0.5-7.1 years) in children carrying prothrombotic risk factors compared to non-carriers (0.9 years (0.1-4.0; p = 0.01). Two patients presenting with neonatal stroke due to elevated Lp a and the FII GA variant showed haemorrhagic stroke transformation triggered by severe haemophilia. In addition, when haemophilia A was corrected by administration of factor VIII concentrates eight out of 25 children with central lines in place developed catheter-related thrombosis. Conclusion: The data of this multicentre cohort study demonstrate that the clinical phenotype of severe haemophilia A in childhood is clearly influenced by the coinheritance of prothrombotic risk factors.

Symptomatic Onset of Severe Hemophilia A in Childhood is Dependent on the Presence of Prothrombotic Risk Factors

It has been recently suggested that the clinical phenotype of severe hemophilia A (HA) is influenced by co-inheritance with the factor V G1691A mutation. We therefore investigated 124 pediatric PUP patients with hemophilia (A: n = 111) consecutively admitted to German pediatric hemophilia treatment centers. In addition to factor VIII activity, the factor V (FV) G1691A mutation, the prothrombin (PT) G20210A variant, antithrombin, protein C, protein S and anti-thrombin were investigated. 92 out of 111 HA patients (F VIII activity < 1%) were suffering from severe HA. The prevalence of prothrombotic risk factors in children with severe HA was no different from previously reported data: FV G1691A 6.5%, PT G20201A 3.2%, and protein C type I deficiency 1.1%. No deficiency states of antithrombin or protein S were found in this cohort of hemophilic patients. The first symptomatic bleeding leading to diagnosis of severe hemophilia (< 1%) occurred with a median (range) age of 1.6 years (0.5-7.1) in children carrying defects within the protein C pathway or the PT gene mutation compared with non-carriers of prothrombotic risk factors (0.9 years (0.1-4.0; p = 0.01). The cumulative event-free bleeding survival was significantly prolonged in children carrying additionally prothrombotic defects (log-rank/Mantel-Cox: p = 0.0098). In conclusion, data of this multicenter cohort study clearly demonstrate that the first symptomatic bleeding onset in children with severe HA carrying prothrombotic risk factors is significantly later in life than in non-carriers.

Risk Factors for the Progression from Low to High Titres in 260 Children with Severe Haemophilia A and Newly Developed Inhibitors

In children with severe haemophilia A, inhibitors to factor VIII (FVIII) usually develop during the first 50 treatment exposure days and are classified as low or high titre depending on the peak inhibitor titre being greater or less than 5 Bethesda units/mL (BU/mL). Classification of the inhibitor may change with time, as some low-titre inhibitors progress to high titre following re-exposure to FVIII concentrate. The aim of this study was to investigate potential risk factors for such a progression in children with severe haemophilia A and newly diagnosed inhibitors. This study was a follow-up study of the PedNet Registry and included 260 children with severe haemophilia A and inhibitors born between 1990 and 2009 and recruited consecutively from 31 haemophilia centres. Clinical and laboratory data were collected from the date of each child's first positive inhibitor test for at least 3 years. At the time of first positive inhibitor test, 49% (n = 127) had low-titre inhibitors, with 50% of them progressing to high titre and only 25% maintaining low titres. The FVIII gene (F8) mutation type was known in 247 patients (95%), and included 202 (82%) null mutations. The progression to high-titre inhibitors was associated with null F8 mutations (odds ratio [OR]: 2.6; 95% confidence interval [CI]: 1.0–6.5), family history of inhibitors (OR: 7.2; 95% CI: 1.8–28.4) and the use of high-dose immune tolerance induction, defined as ≥100 IU FVIII concentrate/kg/d (OR: 3.9; 95% CI: 1.5–10.0). These results suggest that high-dose immune tolerance induction should be avoided as the initial strategy in patients who develop low-titre FVIII inhibitors.

Increased fasting total homocysteine plasma levels as a risk factor for thromboembolism in children

Elevated total homocysteine (tHcy) concentrations are an inde- pendent risk factor for thromboembolic events in adults. In children with moderate hyperhomocysteinemia data are sparse. Therefore, between 1995 and 2002 we consecutively recruited 163 white pediatric patients with a first symptomatic thromboembolic event and 255 healthy controls (mean age: 6.4 years in patients vs. 6.6 years in controls, range: 3 months to 18 years) and measured fasting tHcy levels. Median tHcy levels in patients were significantly higher (6.6 µmol/l, range 2.9-20.4 µmol/l) than in controls (5.7 µmol/l, 2.0-14.0 µmol/l, p<0.0001). 48 of the 163 patients with thromboembolism (29.5%) versus 26 of the 255 controls (10.2%) had tHcy levels above the age- specific normal 90th percentile (OR 2.9, 95%CI: 1.7-4.8). The odds ratio for children in the highest quintile compared to chil- dren with levels in the lowest quintile was 4.3 (1.6-8.1; highest quintile: median tHcy level 9.6 µmol, range 8.0-20.4), showing a significantly increased risk for thromboembolic disease with even mild hyperhomocysteinemia. We conclude that hyperho- mocysteinemia above the age-specific cut-off values is a risk fac- tor for thromboembolic events in children. Therefore, screen- ing for elevated fasting tHcy levels of patients with thromboem- bolism is recommended to stratify the risk of thromboembo- lism.

Role of protein S deficiency in children with venous thromboembolism

Venous thromboembolism [TE] is a multifactorial disease, and protein S deficiency [PSD] constitutes a major risk factor. In the present study the prevalence of PSD and the clinical presentation at TE onset in a cohort of children is reported. In 367 unselected paediatric patients with TE (age 0.1–18 years) recruited between July 1996 and December 2013, a comprehensive thrombophilia screening was performed along with recording of anamnestic data. Thirty of 367 paediatric patients (8.2 %) derived from 27 families had PSD. Mean age at first TE onset was 14.5 years (range 0.1 to 18). Thrombotic locations were cerebral veins (n=8), calf vein TE (n=3) deep veins (DVT) of the leg (n=12), DVT & pulmonary embolism (n=5) and intra-cardiac veins (n=1) or purpura fulminans (n=1). PSD co-occurred with the factor 5 mutation at rs6025 or the homozygous factor 2 susceptibility variant at rs1799963 in one case each. The Heerlen polymorphism detected in five children presented with milder PSD. In 18 patients (60 %) a concomitant risk factor for TE was identified. A second TE event within primarily healthy siblings occurred in three of 27 PSD families (11.0 %). In this cohort of children with symptomatic TE, the prevalence of PSD adjusted for family status was 7.4 %. 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.

Effects of primary and secondary prophylaxis on the clinical expression of joint damage in children with severe haemophilia A

Patients with severe haemophilia A (HA) can either be treated by regular FVIII infusions twice or three times per week (prophylaxis), or only in case of bleeding episodes (on-demand). Whereas prophylaxis reduces the number of bleeding episodes and may therefore prevent the development of haemophilic arthropathy, there is still a lot of controversy surrounding recommendations on age and dose at start of prophylactic regimens. The present database study was performed to investigate the role of primary versus secondary prophylaxis in HA children. The outcome variable was imaging-proven haemophilic joint damage. Forty-two children were initially treated with primary prophylaxis following the first bleeding episode, and were frequency-matched (year of birth, catchment area) to 67 pa- tients receiving “on-demand” therapy with an early switch to “secondary prophylaxis”. In multivariate analysis adjusted for the HA mutation type and the presence or absence of thrombophilia, the Pettersson score investigated at a median age of 12.5 years in joints with at least one documented bleeding episode was not significantly different between the two patient groups (p=0.944),and no statistically significant differences were found in patients with target joints (p=0.3), nor in children in whom synovitis had occurred (p=0.77). No conclusion can be drawn from the data presented herein whether primary prophylaxis or an early start of secondary prophylaxis is superior with respect to joint outcome in children with severe HA.

Epileptic Seizure, Postictal Hemiparesis, and Hyperleukocytosis

Introduction: Acute ischemic stroke (AIS) is a rare event in infancy. Besides vasculopathy, thrombophilia, or cardiac disorders, cancer and chemotherapy are known predisposing factors for AIS. Leukemia can be associated with different abnormal coagulation parameters, but severe bleeding or thrombosis occurs rarely. Clinical Course: We report the case of a 2-year-old boy who was presented to our emergency ward after a prolonged seizure with right sided postictal hemiparesis. Cranial computed tomography scan revealed a large infarction and edema due to thrombosis of the left carotid artery, the middle cerebral artery, and the anterior cerebral artery. Laboratory workup showed 196 g/L leukocytes with 75% myeloid blast cells. Immediate exchange transfusion, hydration, and chemotherapy with cytarabine were started. During the hospital course intracranial pressure increased and the patient developed a unilateral dilated pupil unresponsive to light. Cranial computed tomography scan revealed a new infarction in the right middle cerebral artery territory. Refractory increased intracranial pressure and brain stem herniation developed, and the child died 3 days after admission to hospital. Conclusion: Seizures with postictal hemiparesis due to cerebral infarction can be a rare manifestation of acute myeloid leukemia. Leukocytosis and cancer-induced coagulopathy are main reasons for thrombosis and/or hemorrhage. High leukocyte counts need immediate interventions with hydration, careful chemotherapy, and perhaps exchange transfusion or leukapharesis. In the presence of thrombosis, anticoagulation must be discussed despite the risk of bleeding due to hyperfibrinolysis and low platelet counts. Mortality may be reduced by awareness of this rare presentation of leukemia and prompt institution of leucoreductive treatment.

Ultrasound Assisted Endovascular Thrombolysis in Adolescents: 2 Case Reports

Descending iliofemoral thrombosis in children is a rare event. Anticoagulation therapy with low-molecular-weight-heparin is standard of care. However, patency cannot be achieved in all cases, increasing the risk for rethrombosis and postthrombotic syndrome. To reduce the risk of venous valve failure in adults, local catheter-directed thrombolysis is used to reopen vessels. Two adolescent girls (17 and 15 years old) presented with acute descending iliofemoral thrombosis of the left common iliac, external, and common femoral veins. Anticoagulation with enoxaparin was started until insertion of an EkoSonic Mach 4e catheter for ultrasound-assisted local thrombolysis with recombinant tissue plasminogen activator and administration of unfractionated heparin. Success was monitored by increases in D-dimer levels and ultrasound findings. After 24 hours respectively 48 hours, complete recanalization was obtained. No complication occurred except minimal local bleeding. Screening for hereditary thrombophilia revealed a heterozygous antithrombin mutation in 1 girl (ie, the 15-year-old). May-Thurner syndrome was identified in both girls, necessitating stenting of the left common iliac veins and continuation of anticoagulation therapy with enoxaparin and acetylsalicylic acid. No rethrombosis or complications occurred during the follow-up period. Ultrasound-assisted catheter-directed local thrombolysis with the EkoSonic Mach 4e system was effective in achieving immediate recanalization of the occluded veins and should be considered in children experiencing descending iliofemoral thrombosis. The fast recanalization might reduce the incidence of postthrombotic syndrome. May-Thurner syndrome is regularly found in these patients, and if present, requires stenting of the common iliac vein to avoid early reocclusion. However, long-term patency of iliac vein stenting in children remains to be examined.

Impact of high-risk thrombophilia status on recurrence among children with a first non-central-venous-catheter-associated VTE: an observational multicentre cohort study

Deficiency of antithrombin (AT), protein C (PC) or protein S (PS) constitutes a major risk factor for venous thromboembolism (VTE). Individuals at high risk for recurrence who benefit from screening need to be identified. The primary study objective was to determine the individual recurrence risk among children with a first non-central-venous-catheter-associated VTE with respect to their thrombophilia status and to evaluate if the clinical presentation at first VTE onset differs between children with AT, PC or PS deficiency versus no thrombophilia. We calculated the absolute risk of VTE recurrence and event-free-survival adjusted for thrombophilia, age, sex and positive family VTE history in 161 consecutively enrolled paediatric VTE patients. The presence of a deficiency relative to no thrombophilia was evaluated as a potential predictor of recurrence. Predictors for recurrence were AT deficiency (hazard ratio/95% CI: 6·5/2·46-17·2) and female gender (2·6/1·1-6·35). The annual recurrence rates (95% CIs) were 5·4% (2·6-10) in AT-deficient children, 1·3% (0·3-3·8) in patients with PC deficiency, 0·7% (0·08-2·4) in the PS-deficient cohort and 0·9% (0·4-1·8) in patients with no thrombophilia. Positive family VTE history or combined thrombophilias did not predict recurrence. Given the overall annual incidence rate of recurrence of 1·5% we suggest screening for AT deficiency in children with VTE.

[Haemostatic disorders in children]

Haemorrhagic and thrombotic events occur in both children and adults. The underlying causes are congenital or acquired disorders. In contrast to haemorrhagic disorders, inherited thrombotic disorders nearly exclusively in association with additional external risk factors lead to thrombotic events predominantly during the newborn period and adolescence. It is necessary to be aware of age-specific properties of coagulation in order to correctly interpret clinical and laboratory findings and to provide optimal care for children with haemorrhagic and thrombotic complications.

Increased inhibitor incidence in severe haemophilia A since 1990 attributable to more low titre inhibitors

Many studies have reported an increased incidence of inhibitors in previously untreated patients (PUPs) with severe haemophilia A after the introduction of recombinant products. It was the objective of this study to investigate whether the inhibitor incidence has increased between 1990 and 2009 in an unselected cohort of PUPs with severe haemophilia A (FVIII< 1 %). Patients were consecutively recruited from 31 haemophilia treatment centres in 16 countries and followed until 50 exposure days or until inhibitor development. Inhibitor development was studied in five-year birth cohorts comparing cumulative incidences. Furthermore the risk for inhibitor development per five-year birth cohort was studied using multivariable Cox regression, adjusting for potential genetic and treatment-related confounders. A total of 926 PUPs were included with a total cumulative inhibitor incidence of 27.5 %. The inhibitor incidence increased from 19.5 % in 1990-1994 (lowest) to 30.9 % in 2000-2004 (highest; p-value 0.011). Low titre inhibitor incidence increased from 3.1 % in 1990-1994 to 10.5 % in 2005-2009 (p-value 0.009). High titre inhibitor incidences remained stable over time. After 2000, risk of all inhibitor development was increased with adjusted hazard ratios 1.96 (95 % CI 1.06-2.83) in 2000-2004 and 2.34 (1.42-4.92) in 2005-2009. Screening for inhibitors was intensified over this 20-year study period from a median of 1.9 to 2.9 tests/year before 2000 to 2.7 to 4.3 tests/year after 2000. In conclusion, the cumulative inhibitor incidence has significantly increased between 1990 and 2009. The high titre inhibitor incidence has remained stable.