[Improvement of the diagnostic accuracy in patients with suspected rheumatic disease by preselection in the early arthritis clinic : An alternative to the appointment service point model of the Healthcare Improvement Act]. / Verbesserung der diagnostischen Treffsicherheit bei Patienten mit vermuteter rheumatischer Erkrankung durch Vorselektion in der Früharthritissprechstunde : Eine Alternative zum Termin-Servicestellen-Modell des Versorgungsstärkungsgesetzes?

The diagnosis and treatment of inflammatory rheumatic diseases can be delayed by a long waiting period for an appointment with a rheumatologist. This study investigated whether preselection of patients in an early arthritis clinic is a suitable tool to improve this situation. In 2006 an early arthritis clinic was founded by the Collaborating Center of Rheumatology in Halle (Saale). General practitioners refer patients by using a special registration form that helps to identify patients with an early joint swelling or inflammatory back pain. Patients are then allocated to a pool of participating rheumatologists and are seen by one of them within 2 weeks. For our scientific evaluation the data of 248 patients from the early arthritis clinic and data of 187 regular patients were gathered by means of an additional questionnaire for rheumatologists and patients. In the early arthritis clinic 40.3 % of patients received the diagnosis of an inflammatory rheumatic disease compared with 19.3 % in the control group. In the latter group 51 % were diagnosed as having degenerative joint or spine disorders compared with 22 % in patients from the early arthritis clinic; however, 61 % of patients who were referred to the early arthritis clinic did not fulfill the criteria of the registration form. On the other hand, patients in this group fulfilling these criteria had an inflammatory rheumatic disease in 68.1 % of the cases. The mean duration of symptoms at the time of first rheumatological consultation was significantly shorter in the early arthritis clinic than in the control group (6 vs. 39 months). Our data demonstrate that the preselection of patients can serve as a useful instrument to guide the referral of patients to rheumatologists. The high percentage of patients who did not fulfil the criteria of the registration form indicates that a further improvement of this form is necessary and stresses the need for intensive communication between rheumatologists and general practitioners. Early arthritis clinics may be an alternative to the current efforts of the legislative authorities to improve specialist care by centralized distribution of specialist appointments.

[Von Willebrand disease type 1 and pregnancy]. / Von-Willebrand-Syndrom Typ 1 und Schwangerschaft.

The von Willebrand-Jürgens syndrome (VWJS) type 1 is a common hereditary bleeding disorder with a bleeding tendency located especially in the mucous membranes. Women suffering from VWJS type 1 show menorrhagia and prolonged postoperative bleedings. During pregnancy the clinical presentation varies by the increase of the von Willebrand factors. In this article the laboratory findings and the clinical presentation of patients with VWJS during pregnancy was examined. The necessity of interventions during pregnancy and at the time of delivery was under consideration.

Aspirin versus low-dose low-molecular-weight heparin: antithrombotic therapy in pediatric ischemic stroke patients: a prospective follow-up study.

BACKGROUND AND PURPOSE: We sought to compare different antithrombotic secondary treatments (mainly medium-dose aspirin with low-dose low-molecular-weight heparin [LMWH]) in pediatric patients with a first ischemic stroke onset with regard to the risk of stroke recurrence. METHODS: The population comprised 135 consecutively recruited children aged >/=6 months to

Symptomatic ischemic stroke in full-term neonates : role of acquired and genetic prothrombotic risk factors.

BACKGROUND AND PURPOSE: The present multicenter case-control study was prospectively designed to assess the extent to which single and combined clotting factor abnormalities influence the onset of symptomatic ischemic stroke in full-term neonates. METHODS: Lipoprotein (Lp)(a); the factor V (FV) G1691A mutation; the prothrombin (PT) G20210A variant; the methylenetetrahydrofolate reductase (MTHFR) T677T genotype; antithrombin; protein C; protein S; and anticardiolipin antibodies (ACAs) were investigated in 91 consecutively recruited neonatal stroke patients and 182 age- and sex-matched healthy controls. RESULTS: Sixty-two of 91 stroke patients (68.1%) had at least 1 prothrombotic risk factor compared with 44 control subjects (24.2%) (odds ratio [OR]/95% confidence interval [CI], 6.70/3.84 to 11.67). An increased Lp(a) level (>30 mg/dL) was found in 20 patients and 10 controls (OR/95% CI, 4.84/2. 16 to 10.86); FV G1691A was present in 17 patients and 10 controls (OR/95% CI, 3.95/1.72 to 9.0); the PT G20210A variant was detected in 4 patients and 4 controls (OR/95% CI, 2.04/0.49 to 8.3); the MTHFR TT677 genotype was found in 15 patients and 20 controls (OR/95% CI, 1.59/0.77 to 3.29); and protein C type I deficiency was found in 6 neonates. Neither antithrombin deficiency nor protein S deficiency was found in the neonatal patients studied. Acquired IgG ACAs were found in 3 cases. Additional triggering factors, ie, asphyxia, septicemia, maternal diabetes, and perinatally acquired renal venous thrombosis, were reported in 54.0% of patients. CONCLUSIONS: Besides acquired triggering factors, the data presented here suggest that genetic prothrombotic risk factors play a role in symptomatic neonatal stroke.

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 antithrombin 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.

Prothrombotic risk factors in children with spontaneous venous thrombosis and their asymptomatic parents: a family study.

The present study was designed to assess to what extent single and combined clotting abnormalities influence spontaneous vascular accidents in pediatric patients, and how the children affected differ in their prothrombotic risk profiles from their biological first-degree family members. In addition, this study was performed to investigate if relatively mild thrombophilic polymorphisms not leading to thrombosis in the parents cause severe clinical expression when coinherited with an established prothrombotic risk factor. The factor V (FV) G1691A mutation, the prothrombin (PT) G20210A variant, the methylenetetrahydrofolate reductase (MTHFR) T677T genotype, the plasminogen activator inhibitor (PAI)-1 promoter polymorphism, lipoprotein (Lp)(a), antithrombin, protein C, and protein S were investigated in 48 childhood patients aged neonate to <18 years (median 0.5 years) with spontaneous venous thromboembolism (SVT) compared with the carrier status of their first-degree family members. In 19 of the 48 patients (39.6%), one prothrombotic risk factor was diagnosed, and in 27 of the 48 subjects (56.3%) at least two prothrombotic defects/alleles. In the majority of cases with SVT, the FV G1691A mutation was involved either with a second mutated allele or combined with elevated Lp(a), the 4G/4G genotype of the PAI -1 promoter polymorphism, and the T677T MTHFR genotype. The rate of combined prothrombotic risk factors was significantly higher in childhood patients compared with their parents. In conclusion, based on the data presented here we suggest that early-onset SVT in childhood patients is mainly caused by combinations of at least two prothrombotic risk factors.

Haemophilia and thrombophilia. What do we learn about combined inheritance of both genetic variations?

UNLABELLED: 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.

Clot waveform analysis in patients with haemophilia A.

UNLABELLED: Clot waveform analysis extends the interpretation of aPTT measurement curves. The curve is mathematically processed to obtain information about fibrin formation kinetics including semiquantitative determination of thrombin, prothrombinase and tenase activity. PATIENTS, METHOD: In this study the feasibility of clot waveform analysis for monitoring of haemophilia A was investigated using blood samples from healthy controls as well as haemophilia A patients under various clinical conditions. RESULTS: Thrombin, prothrombinase and tenase activity show a high correlation to factor VIII levels. Tenase activity was found to exhibit a linear relationship to factor VIII levels over a very large concentration range and was able to discriminate patients with severe, moderate and mild haemophilia. CONCLUSION: Clot waveform analysis is an easy, fast and cheap method to access disturbances in clot formation and can be done without any additional measurements beside an aPTT.

[Cardiac surgery in severe haemorrhagical diseases]. / Kardiochirurgische Eingriffe bei schweren Blutungsdiathesen.

Cardiovascular diseases are the most common disorder in the developed countries. Invasive cardiological and cardiosurgical techniques are known therapies. Yet, patients with severe hereditary haemorrhagical diseases (haemophilia, rare deficiencies of coagulation factors) have an increased bleeding risk by the use of anticoagulants. Therefore, the treatment of these patients requires a concomitant therapy. This article shows eight patients with a severe bleeding diathesis and cardiosurgical interventions in the years 2006 to 2011. This case report shall demonstrate that an adequate therapy can be accomplished with the help of a good cooperation between haemostaseologists and colleagues of the cardioinvasive/cardiosurgical disciplines.

[Thrombosis of the iliac artery in a premature neonate: thrombolytic therapy using rt-PA]. / Arteria iliaca-Thrombose bei einem Frühgeborenen: Lysetherapie mit rt-PA.

Thromboembolic events in neonates are very rare. They are often associated with severe disease affecting the newborn or are secondary to central venous lines or arterial catheters. Most of the described cases of thromboses of the iliac or femoral arteries are associated with cardiac catheterisation or femoral invasive blood pressure monitoring. The relationship between single umbilical arteries and an increased incidence of structural and chromosomal anomalies is well known, but a higher rate of thromboembolic disease in infants with single umbilical arteries has not been described. Rt-PA (recombinant tissue plasminogen activator) has been successfully used in small studies and numerous case reports. To date controlled clinical trials giving guidelines for antithrombotic therapy using rt-PA are still lacking. We report the clinical course of a 700 g premature male, who was born by Caesarean section at 29 + 6 gestational weeks. On the fifth day the baby suffered from arterial thrombosis of the right pelvis axis. Antenatally a single umbilical artery was identified. Iliac arteries on the involved site appeared hypoplastic. Additionally, the prothrombin G20210A mutation was found. The patient was treated successfully using recombinant tissue plasminogen activator. In the case of a high risk of limb or organ loss due to arterial thrombosis, thrombolysis using rt-PA is justified. Appropriate rt-PA treatment has been studied for the adult but not the paediatric population. Hence, well-designed clinical trials are necessary to determine the pharmacokinetics and dynamics of thrombolytic agents in children.

[Acute hepatotoxicity with intermediate-dose methotrexate in children with leukemia and non-Hodgkin's lymphoma]. / Akute Hepatotoxizität bei mittelhochdosiertem Methotrexat bei Kindern mit Leukämien und Non-Hodgkin-Lymphomen.

In the period of 1.1.1988 to 1.5.1992 49 children, 28 boys and 21 girls, were treated with 219 MTX infusions. The acute hepatotoxicity was investigated from day--1 to day 5 of treatment duration. 30 patients suffered of a ALL, 6 of a relapse of a ALL, 3 of a ANLL and 10 of a NHL. We studied the MTX dosage and the infusion time. At all patients the determination of the activity of the liver enzymes ASAT, ALAT and GGTP in the serum took place according to the treatment protocol. The increase of enzymes activity correlated with the intensity and kind of hepatocellular damage. Partly the extreme increase of lesion parameters is not the expression of an irreversible cytonecrosis. Beside the ALAT also the GGPT is a sensitive predictor of hepatocellular lesion. The high enzyme activity before the MTX application is a indicator of a preexistent cell damage of the liver. The hepatotoxicity measured in the serum was highly correlated with the AUC.

Factor V G1691A and prothrombin G20210A in childhood spontaneous venous thrombosis--evidence of an age-dependent thrombotic onset in carriers of factor V G1691A and prothrombin G20210A mutation.

UNLABELLED: Risk factors for venous thrombosis in adults are the prothrombin (PT) G20210A, the factor (F) V G1691A mutations and hereditary deficiencies of protein C, protein S and antithrombin. However, data are limited on the relevance of these risk factors for thrombosis in children and adolescents. We therefore investigated 119 patients aged 0-18 with spontaneous venous thrombosis and controls (n = 100) for the presence of the factor V G1691A mutation and the prothrombin G20210A variant with respect to thrombotic onset and thrombosis location. The following frequencies (patients vs. controls), odds ratios (OR), 95%-confidence intervals (CI) and p-values were found: FV G1691A, 19.3% vs. 5%, OR/CI 4.55/1.66-12.5, p = 0.0038 and prothrombin G20210A, 8.4% vs. 3%, OR/CI 2.96/0.8-11, p = 0.17. A combination of the FV G1691A mutation with the PT G20210A variant was found in 3 children (2.5% of cases) but only once in the controls. With a median (range) age of 2 years (0-17), carriers of the FV mutation were significantly younger compared with patients carrying the PT variant (16 years: 0-18, p < 0.001). Vascular accidents in carriers of the FV mutation occurred in deep veins of the leg (n = 11), cerebral veins (n = 4), renal veins (n = 3) and portal veins (n = 2). Patients with the PT mutation showed spontaneous thrombosis in the majority of cases in the deep veins of the leg (n = 5) and in the central nervous system (n = 2). Combined defects were found in a neonate with renal venous thrombosis and in two adolescents with deep vein thrombosis. CONCLUSION: Data presented here suggest that the heterozygous FV mutation is the most commonly found prothrombotic risk factor responsible for spontaneous thrombosis during infancy and early childhood. In contrast, the PT G20210A variant is likely to be more important during puberty and adolescence.

Role of genetic prothrombotic risk factors in childhood caval vein thrombosis.

UNLABELLED: Childhood caval vein thrombosis has a high incidence especially in the first year of life. Besides deficiencies of protein C, protein S, antithrombin and plasminogen, the factor (F) V G1691A mutation, the prothrombin (PT) G20210A variant, the methylenetetrahydro-folate reductase (MTHFR) TT677 genotype, or increased lipoprotein (Lp) (a) > 30 mg/dl have emerged as important prothrombotic risk factors in childhood vascular accidents. 27 consecutive childhood patients with inferior caval vein thrombosis and 100 healthy age-matched controls were investigated for the presence of these prothrombotic risk factors with respect to the first thrombotic onset. In 19 out of 27, patients thrombosis occurred during infancy; the remaining vascular accidents were diagnosed during puberty. In 13 out of the 19 infants, vascular occlusion occurred spontaneously, five times associated with renal venous thrombosis. 68.4% of patients in the first year of life (n = 13) showed at least one prothrombotic risk factor. The FV mutation (heterozygous n = 4, homozygous n = 1). Lp (a) > 30 mg/dl and kringle 4 repeats < 28 (n = 4), MTH FR TT677 with mild hyperhomocysteinaemia (> 95th age-dependent percentile, i.e. 8.5 micromol/l: n = 3) and antithrombin deficiency type II (n = 1) were diagnosed with an overall odds ratio/95% confidence interval of 9.2/3.1-27.4. In the adolescent group, genetic risk factors were found in 50% of patients investigated (FV mutation (n = 1), PT variant (n = 3); odds ratio/95% confidence interval: 4.2/0.97-18.6). CONCLUSION: Data presented here suggest that genetic prothrombotic risk factors play an important role in childhood caval vein thrombosis. Remarkably, during puberty and adolescence the predominant defect diagnosed was the PT G20210A variant, whereas the FV G1691A mutation had a higher incidence during infancy.

Cerebral venous sinus thrombosis in children with acute lymphoblastic leukemia carrying the MTHFR TT677 genotype and further prothrombotic risk factors.

BACKGROUND: The present study was designed to prospectively evaluate the role of prothrombotic risk factors in leukemic children treated according to the ALL-BFM 90/95 study protocols with respect to the onset of cerebral venous sinus thrombosis. PATIENTS: 317 consecutive leukemic children aged 6 months to 18 years were enrolled in this study. 288 of the 317 patients were available for thrombosis-free survival analysis. RESULTS: In 17 (5.9%) of these 288 patients cerebral venous sinus thrombosis occurred. The overall event-free survival of thrombosis in the central nervous system in patients with at least one prothrombotic defect (n = 12) was significantly reduced compared with patients without a prothrombotic defect (p < 0.0001). 15 patients showed acute clinical symptoms at onset of cerebral venous sinus thrombosis, two were asymptomatic. Three of the 17 patients affected (17.6%) died directly associated with the thrombotic event during induction therapy, the remaining 14 patients did not show prolonged clinical symptoms. CONCLUSIONS: Prothrombotic risk factors should be included in a screening program in ALL children treated according to the BFM study protocols. Further prospective studies are recommended to establish adequate prophylactic anticoagulant treatment during ALL (BFM) polychemotherapy.

The 677T genotype of the common MTHFR thermolabile variant and fasting homocysteine in childhood venous thrombosis.

Controlled data on the association of MTHFR genotypes, hyperhomocysteinaemia and their interaction with factor V G1691A with childhood thrombosis are not yet available. Therefore we conducted a case-control study comparing 141 childhood patients with venous thrombosis with 345 healthy controls. The MTHFR C677T genotypes, FV G1691A and prothrombin G20210A were evaluated; in addition, fasting homocysteine concentrations were measured in a subgroup of 60 children and 80 healthy controls. 10.4% of the healthy control population showed the MTHFR TT genotype, 34.2% the CT genotype and 55.4% the CC variant. MTHFR genotypes account for fasting homocysteine concentrations in healthy controls (CC: 5.5 micromol/l (4-7.2); CT: 7 micromol/l (3.9-9.8); TT: 12.1 micromol/l (7.7-13.3)) with an upper age-specific 95th percentile of 8.3 micromol/l. The following frequencies (patients versus controls), odds ratios (OR) and 95% confidence intervals (CI) were found for single defects: MTHFR 677TT genotype (10.6% vs. 10.4%; OR/CI: 1.02/0.54-1.93; P = 0.99) and CT genotype (43.8% vs. 34.2%; OR/CI: 2.12/1.42-3.16; P = 0.0000). A combination of FV G1691A mutation and MTHFR 677CT genotype was found in 9.9% of patients and in 2.9% of the controls (OR/CI: 3.8/1.64-8.75; P = 0.027). Fasting homocysteine median (range) concentrations in the patient group were significantly higher than in the controls (7 micromol/l (3-23) vs. 5.5 micromol/l (3-8.4): P = 0.0004), and homocysteine concentrations >8.3 micromol/l were found in 40% of patients vs. 2.5% of the controls (OR/CI: 22/2.64-183; P = 0.0003). Conclusion Data of this childhood case-control study suggest that mildly elevated fasting homocysteine concentrations >8.3 micromol/l and the CT genotype of the MTHFR C677T variant are significant risk factors for venous vascular occlusion in children.

Abdominal venous thrombosis in neonates and infants: role of prothrombotic risk factors - a multicentre case-control study. For the Childhood Thrombophilia Study Group.

The factor V (FV) G1691A mutation, the prothrombin (PT) G20210A variant, the methylenetetrahydrofolate reductase (MTHFR) T677T genotype, together with fasting homocysteine (HCY) concentration, lipoprotein (Lp)(a), anti-thrombin (AT), protein C (PC), protein S (PS) and anti-cardiolipin antibodies were investigated in 65 consecutively recruited infants (neonate to < 12 months) with renal venous thrombosis (RVT; n = 31), portal vein thrombosis (PVT; n = 24) or hepatic vein thrombosis (HVT n = 10), and 100 age- and sex-matched healthy controls. FV G1691A was found in 14 babies (heterozygous: RVT n = 9, PVT n = 4; homozygous HVT n = 1) and five controls, the MTHFR TT677 genotype together with increased HCY in four infants with thrombosis (RVT n = 2; PVT n = 1; HVT n = 1) compared with one control, and the PT G20210A variant was present in one control only. PC type I deficiency was diagnosed in three patients (RVT n = 2; PVT n = 1) and AT deficiency in two patients (RVT n = 1; PVT n = 1). Three neonates with spontaneous thrombosis showed FV G1691A combined with Lp(a) and the FV G1691A was combined with the PT G20210A genotype in two infants. Additional triggering factors were reported in 27 patients (41.5%). The overall odds ratios (ORs) and 95% confidence intervals (CIs) with respect to the different thrombosis locations were: RVT (OR/CI: 10.9/3.85-31.1; P < 0.0001), PVT (5.47/1.7-17.6; P < 0.0007) and HVT (3.3/0.58-18.7; P = 0.18). The data presented here suggest that genetic prothrombotic risk factors also play an important role in abdominal venous thrombosis during infancy.

Risk of recurrent venous thrombosis in children with combined prothrombotic risk factors.

After a first episode of spontaneous venous thromboembolism (VTE), the risk of recurrence persists for many years. However, comprehensive data about the risk of recurrence in pediatric patients have hitherto not been reported. Thus, this study evaluated the risk of recurrent VTE among children in relation to the presence of single or combined-inherited and/or acquired causes of thrombophilia. A total of 301 patients aged neonate to 18 years (median, 6 years) who were referred for an objectively confirmed first episode of spontaneous VTE were followed prospectively for a median time of 7 years (range, 6 months to 15 years) after withdrawal of anticoagulation. All patients were studied for established acquired and inherited causes of thromboembolism. With reference to all 301 patients, one single prothrombotic risk factor was found in 176 subjects (58.5%), whereas combined defects were found in 20.6% (n = 62). Recurrent VTE occurred in 64 patients (21.3%) within a median time of 3.5 years (range, 7 weeks to 15 years) after withdrawal of anticoagulation, with a significantly shorter cumulative thrombosis-free survival in children carrying combined defects (P <.0001; chi-square, 42.2). The factor V G1691A mutation was present in the majority of patients with recurrent VTE. Including genetic defects, gender, and acquired risk factors, multivariate analysis showed that only the presence of prothrombotic defects increases the risk of recurrent VTE (single defect: odds ratio [OR], 4.6; 95% confidence interval [CI], 2.3-9.0; P <.0001; combined defect: OR, 24.0; 95% CI: 5.3-108.7; P <.0001). As a consequence of the data presented here, it is suggested that screening for genetic risk factors be done among pediatric patients with VTE.

Prospective evaluation of the thrombotic risk in children with acute lymphoblastic leukemia carrying the MTHFR TT 677 genotype, the prothrombin G20210A variant, and further prothrombotic risk factors.

The reported incidence of thromboembolism in children with acute lymphoblastic leukemia (ALL) treated with L-asparaginase, vincristine, and prednisone varies from 2.4% to 11.5%. The present study was designed to prospectively evaluate the role of the TT677 methylenetetrahydrofolate reductase (MTHFR) genotype, the prothrombin G20210A mutation, the factor V G1691A mutation, deficiencies of protein C, protein S, antithrombin, and increased lipoprotein (a) concentrations in leukemic children treated according to the ALL-Berlin-Frankfurt-Muenster (BFM) 90/95 study protocols with respect to the onset of vascular events. Three hundred and one consecutive leukemic children were enrolled in this study. Fifty-five of these 301 subjects investigated had one established single prothrombotic risk factor: 20 children showed the TT677 MTHFR genotype; 5 showed the heterozygous prothrombin G20210A variant; 11 were carriers of the factor V G1691A mutation (heterozygous, n = 10; homozygous, n = 1); 4 showed familial protein C, 4 protein S, and 2 antithrombin type I deficiency; 9 patients were suffering from familially increased lipoprotein (a) [Lp(a)] concentrations (>30 mg/dL). In addition, combined prothrombotic defects were found in a further 10 patients: the FV mutation was combined with the prothrombin G20210A variant (n = 1), increased Lp(a) (n = 3), protein C deficiency (n = 1), and homozygosity for the C677T MTHFR gene mutation (n = 1). Lp(a) was combined with protein C deficiency (n = 2) and the MTHFR TT 677 genotype (n = 2). Two hundred eighty-nine of the 301 patients were available for thrombosis-free survival analysis. In 32 (11%) of these 289 patients venous thromboembolism occurred. The overall thrombosis-free survival in patients with at least one prothrombotic defect was significantly reduced compared with patients without a prothrombotic defect within the hemostatic system (P <.0001). In addition, a clear-cut positive correlation (P <.0001) was found between thrombosis and the use of central lines. However, because the prothrombotic defects diagnosed in the total childhood population studied were all found within the prevalences reported for healthy Caucasian individuals, the interaction between prothrombotic risk factors, ALL treatment, and further environmental factors is likely to cause thrombotic manifestations.

The plasminogen activator inhibitor (PAI)-1 promoter 4G/4G genotype is not associated with ischemic stroke in a population of German children. Childhood Stroke Study Group.

OBJECTIVES: To investigate the relationship between an insertion/deletion (4G/5G) polymorphism of the plasminogen activator inhibitor (PAI)-1 gene and childhood patients with a past history of ischemic stroke. METHODS: The PAI-1 4G/4G genotype and the coinheritance with lipoprotein (Lp) (a) levels, the factor V (FV) G1691A mutation, the prothrombin (PT) G20210A variant, and the methylene-tetrahydrofolate reductase (MTHFR) T677T genotype were studied in 198 Caucasian children with stroke and 951 controls (same age, sex and ethnical distribution). In a randomly selected subgroup of patients/controls (n=60) PAI-I activities have been investigated. RESULTS: The distribution of the 4G/5G genotypes was no different in childhood stroke patients and controls, with a 4G allele frequency of 55.8% in patients compared with 53.8% in control subjects (P=0.49). The 4G/4G genotype compared with the remaining genotypes was present in 43 cases and 167 (17.6% vs. 21.7%; OR/CI: 1.30/0.89-1.98; P=0.3). PAI-1 activity was significantly elevated (P < 0.001) in the patient group. CONCLUSIONS: Data presented here suggest that the 4G/4G genotype is not a major risk factor in the aetiology of childhood ischemic stroke.

Prevalence of factor V Leiden in children with thrombo-embolism.

UNLABELLED: Hereditary resistance to the anticoagulatory action of activated protein C (APC resistance, APCR) was identified as a possible new thrombophilic factor in a high percentage (17%-60%) of young adults with thrombotic events. A single missense mutation (R506Q) due to a G/A transition (G1691A) in exon 10 of the factor V gene is regarded as the causative molecular defect, resulting in factor V Leiden which is correlated with APCR. Identification of this mutation by polymerase chain reaction-based methods is easy to perform and prevents pre-analytical and analytical errors in the coagulometric assay for APCR. Since the impact of this mutation in children with thrombo-embolic disease has not been determined to date, we initiated a multi centre prevalence study in two paediatric populations, with and without thrombo-embolic events. We compared 125 paediatric patients with thrombosis, divided into three different age groups (0 to < 0.5 years; > 0.5 to < 10 years; > 10 to < 18 years) with a normal population of 159 children. Although the mutation G1691A was found with an unexpectedly high prevalence of 12% in our normal controls, the prevalence was significantly higher in the age groups; 0 to < 0.5 years (26%) and > 10 to < 18 years (30%). In patients between > 0.5 and < 10 years the overall prevalence was similar to that of the control group (13%). However, in patients of this age with spontaneous thrombosis, G1691A was also a significant risk factor (5/17 approximately equal to 29%). Homozygosity for G1691A was detected in three patients but not in the control group. Including deficiencies of protein C, protein S, antithrombin, and the presence of anti-phospholipid antibodies, thrombosis was correlated with endogenous thrombophilic factors in 38/125 patients (30.4%). CONCLUSION: Our results emphasize the impact of factor V Leiden on thrombogenesis in children. However, the significance is age-dependent and may reflect the different physiology of haemostasis in the three age groups. The diagnostic workup of children with thrombosis should include tests for factor V Leiden. The correlation of factor V Leiden with the clinical course of thrombo-embolism in children is essential to establish rational guidelines for therapy and prophylaxis of APCR-related thrombosis which are not yet available.