Congenital atresia of the portal vein and extrahepatic portocaval shunt associated with benign neonatal hemangiomatosis, congenital adrenal hyperplasia, and atrial septal defect.

A rare case of congenital atresia of the portal vein and ductus venosus, extrahepatic portocaval shunt, benign neonatal hemangiomatosis, congenital adrenal hyperplasia, and an atrial septal defect is reported. Twenty-two cases of congenital extrahepatic end-to-side shunts have been described before. Although additional anomalies are common in this type of shunt, hemangiomatosis has been described only once. Adrenal hyperplasia has never been reported in this anomaly.

Interaction of fibrinolysis and prothrombotic risk factors in neonates, infants and children with and without thromboembolism and underlying cardiac disease. a prospective study.

UNLABELLED: To evaluate the role of plasminogen activator inhibitor-1 (PAI-1) and tissue-type plasminogen activator (t-PA) in children with an estimated risk of vascular occlusion reported to range from 7% to 16%, we conducted a prospective study in infants and children with underlying cardiac disease. One hundred and twenty-five children (neonate - 16 years) were investigated. In 9 infants out of the 125 children vascular occlusion occurred, closely related to cardiac catheterisation and arterial or venous lines during major cardiac surgery. Six of the nine neonates and infants with (n=6) and without (n=3) prothrombotic risk factors showed evidence of a basically impaired fibrinolytic system. Five of the nine infants showed increased PAI-1 clearly correlated to the 4G/4G genotype of the plasminogen activator-1 promoter polymorphism along with elevated t-PA concentration before the first diagnostic cardiac catheterisation was performed. One infant presented with increased t-PA concentration only. Five of the six children with reduced fibrinolytic capacity had further prothrombotic risk factors. CONCLUSION: Data of this study indicate that neonates and infants with underlying cardiac disease and basically increased PAI-1 due to the 4G/4G variant of the PAI-1 promoter polymorphism along with elevated t-PA levels in combination with further prothrombotic risk factors are at high risk of developing early thromboembolism during cardiac catheterisation.

Infant methylenetetrahydrofolate reductase 677TT genotype is a risk factor for congenital heart disease.

OBJECTIVE: Recently, an association between the homozygous C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene in infants with congenital neural tube defects or congenital oral clefts has been shown. However, no data are available so far with respect to the MTHFR 677TT genotype in children with underlying structural congenital heart disease (CHD). METHODS: We investigated the MTHFR genotype in 114 Caucasian CHD patients aged newborn to 16 years (median 0.6 years; 53% male) and in 228 age- and sex-matched healthy controls. RESULTS: In childhood patients with CHD the homozygous MTHFR 677TT genotype was found in 21 out of 114 subjects (18.4%) compared with 21 out of 228 controls (9.2%; odds ratio (OR) 2.2, 95%-confidence interval (CI) 1.2-4.3; P=0.027). In patients with pulmonary valve stenosis, hypoplastic left heart syndrome, coarctation of the aorta, aortic valve stenosis or subaortic stenosis the frequency of the TT genotype varied between 38 and 67% with corresponding ORs from 6.1 (CI, 1.4-27.5; P=0.034) to 20.4 (CI, 1.8-235.0; P=0.025), whereas in other structural CHD the frequency of this genotype was not significantly different from the controls. CONCLUSIONS: With the present study we can show for the first time that the embryonal MTHFR 677TT genotype is significantly associated with the development of structural congenital heart malformations during early pregnancy. It remains to be clarified, whether this genotype is at least a risk marker or a risk factor for structural congenital heart malformations.

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.

Coagulation and fibrinolysis in children, adolescents, and young adults with inflammatory bowel disease.

BACKGROUND: Patients with Crohn's disease and ulcerative colitis have an increased risk of thromboembolic events. METHODS: Data were collected from 24 patients aged 4.5 to 23 years who had inflammatory bowel disease. Platelet count, antithrombin, fibrinogen, prothrombin fragment F1+2, soluble thrombomodulin, tissue plasminogen activator, D-dimer, and plasminogen activator inhibitor-1 antigen were investigated. In addition the response to activated protein C, the factor V R506Q mutation, protein C, free protein S antigen, and lipoprotein (a) were analyzed. These data were compared with medical treatment, duration, and disease activity, estimated with the Pediatric Crohn's Disease Activity Index or the Clinical Colitis Activity Index. RESULTS: Forty-five percent of our patients showed an increase in fibrinogen, 29% in prothrombin fragment F1+2, and 20% in platelet count, plasminogen activator inhibitor- antigen, and soluble thrombomodulin. Thrombomodulin was higher in active disease than in inactive disease and in Crohn's disease than in ulcerative colitis. Fibrinogen was also higher with Crohn's disease and tended to be higher in active disease than in ulcerative colitis and inactive disease. Plasminogen activator inhibitor-1 antigen was significantly higher in patients with Crohn's disease than in those with ulcerative colitis and was higher in the patient group treated with steroids. CONCLUSION: As has been shown in adults, young patients with active and inactive inflammatory bowel disease were found to have abnormal coagulation and fibrinolysis. The relevance as a thromboembolic risk factor is discussed.

Genetic risk factors of thrombophilia in ischaemic childhood stroke of cardiac origin. A prospective ESPED survey.

UNLABELLED: Ischaemic stroke is a rare event in childhood. In approximately one-fourth of cases an underlying cardiac disease can be detected. We investigated the importance of genetic risk factors of venous thromboembolism in childhood or stroke in adulthood as risk factors for ischaemic stroke in children in a multicentre survey focusing on patients with a cardiac disease. 38 of 162 white infants and children (neonate-18 years) with ischaemic stroke were suffering from a cardiac disorder. An age-matched group of 100 children from the same geographic areas as the patients served as controls. Patients and controls were analysed for increased lipoprotein (a) levels > 30 mg/dl, for the presence of the factor V (FV) G1691A mutation, the prothrombin (PT) G20210 A variant, and deficiencies of protein C, protein S, and antithrombin. The following frequencies (patients vs. controls), odds ratios (OR) and confidence intervals (CI) of single risk factors were found: Lp(a) > 30 mg/dl (18.4% vs. 5%; OR/CI: 4.3/1.3-14.4; p = 0.03), FV G1691A (13.2% vs. 4%; OR/CI 3.63/0.92-14.3; p = 0.12) protein C type I deficiency (15.8% vs. 1%; OR/CI: 18.5/2.15-16.0; p = 0.0017), anticardiolipin antibodies (10.5% vs. 0%; p = 0.0051). No protein S or antithrombin deficiency was found. Combinations of haemostatic disorders were found in 10.5% of cases but in none of the controls (Fisher 0.005). CONCLUSION: While FV G1691A and prothrombin G20210 A mutations show no significant data in our study, lipoprotein (a) levels >30 mg/dl protein C deficiency, anticardiolipin antibodies and combined prothrombotic disorders seem to be important risk factors for manifestation of ischaemic strokes in children with underlying cardiac disorders.

Cerebral venous sinus thrombosis in infancy and childhood: role of genetic and acquired risk factors of thrombophilia.

UNLABELLED: Over a 3 year period the R506Q mutation in the factor V (FV) FV:Q506 gene, FV, factor XII (FXII), prothrombin, protein C, protein S, antithrombin, heparin cofactor II, anticardiolipin antibodies and lipoprotein (a) (Lp(a)) were measured in 32 infants and children with sinus thrombosis. Heterozygous FV:Q506 (n=5), homozygous FV:Q506 (n=2), homozygous FXII deficiency (n=1), protein C deficiency type I (n=5), protein C deficiency type II (n=1), antithrombin deficiency type I (n=1) increased Lp (a) (n=5), activated protein C-resistance without mutation in the FV gene (n=2), and increased anticardiolipin IgG antibodies (n=2) were diagnosed in the children investigated. In a further two patients we found combinations of increased Lp(a) with moderate hyperhomocystinaemia and heterozygous plasminogen deficiency with heterozygous FXII deficiency. In addition, increased anticardiolipin IgG antibodies were found in combination with heterozygous FV:Q506 (n=1) and protein C type I deficiency (n=2) respectively. Out of 32 patients with venous sinus thrombosis, 3 showed additional peripheral venous vascular occlusion. Contributing factors were present in 31 out of 32 patients investigated. Family members of 10 affected children had suffered from venous thrombo-embolism prior to the study. CONCLUSION: Our data suggest that additional contributing factors may promote manifestation of cerebral venous sinus thrombosis in infants and children with an inherited prothrombotic state. Further prospective studies are required to evaluate their potential role as "triggering" agents.

Factor V Leiden and genetic defects of thrombophilia in childhood porencephaly.

AIMS: To determine to what extent the Arg506 to Gln point mutation in the factor V gene and further genetic factors of thrombophilia affect the risk of porencephaly in neonates and infants. METHODS: The Arg506 to Gln mutation, factor V, protein C, protein S, antithrombin, antiphospholipid antibodies and lipoprotein (a) (Lp(a)) were retrospectively measured in neonates and children with porencephaly (n = 24). RESULTS: Genetic risk factors for thrombophilia were diagnosed in 16 of these 24 patients: heterozygous factor V Leiden (n = 3); protein C deficiency type I (n = 6); increased Lp (a) (n = 3); and protein S type I deficiency (n = 1). Three of the 16 infants had two genetic risk factors of thrombophilia: factor V Leiden mutation combined with increased familial Lp (a) was found in two, and factor V Leiden mutation with protein S deficiency type I in one. CONCLUSIONS: The findings indicate that deficiencies in the protein C anticoagulant pathway have an important role in the aetiology of congenital porencephaly.

Factor V Leiden, protein C, and lipoprotein (a) in catheter-related thrombosis in childhood: a prospective study.

OBJECTIVE: To determine the association between catheter-related thromboses and hereditary causes of thrombophilia, including the factor V Leiden mutation, deficiencies of protein C or protein S, or increased lipoprotein (a). STUDY DESIGN: To evaluate the incidence of genetic risk factors for familial thrombophilia in catheter-related thrombosis, 163 consecutively admitted infants and children (cardiac disease and catheter placement [C] n = 140; Broviac catheter [B] n = 23) were prospectively investigated. In addition, an age-matched, healthy control group undergoing elective surgery (S: n = 155) was investigated. RESULTS: Heterozygous factor V Leiden mutation was diagnosed in 20 of the 318 study subjects (C: n = 5; B: n = 4; S: n = 11), homozygous factor V Leiden mutation was found in two subjects (C: n = 1; S: n = 1), protein C deficiency type I was diagnosed in nine subjects (C: n = 4; B: n = 1; S: n = 4), and five subjects showed increased lipoprotein (a) (C: n = 3; S: n = 2). The frequency of thrombosis (C: n = 13; B: n = 5) in patients with familial thrombophilia was significantly higher (p < 0.0001; chi square: 27.79) in the catheter groups (15 of 17 subjects) than in control subjects after minor elective surgery (none of 18). Fifteen of the 18 infants with thrombosis had congenital thrombophilia; two children with congenital thrombophilia did not have documented thrombosis, and three infants with vascular occlusion had no inherited predisposition to thrombophilia. CONCLUSIONS: Genetic risk factors for familial thrombophilia play an important role in the manifestation of catheter-related thromboembolism in children.

Arg506 to Gln mutation in the factor V gene causes poor fibrinolytic response in children after venous occlusion.

To determine to what extent the Arg506 to Gln mutation in the factor V gene influences the fibrinolytic response after 20 min venous occlusion (VO) we investigated a population of APC resistant children (n = 60) and a group of age-matched healthy controls (n = 25). After 20 min VO, symptomatic (n = 30) carriers of the common factor V mutation showed significantly reduced t-PA activities compared with asymptomatic (n = 30) carriers (p <0.0001) and healthy controls (p <0.0001). In contrast, PAI 1 activity was significantly (p <0.0001) higher before and after VO in children with the factor V mutation compared with healthy children. No difference was found between symptomatic and asymptomatic probands. A significantly lower PAI 1 antigen decrease along with a lower t-PA antigen release was found in the APC resistant children compared with the controls. No significant difference was seen between individuals with and without previous vascular insults. As the lack of t-PA activity after VO in symptomatic carriers is the most conspicuous result, we suggest that the factor V gene mutation itself might induce the fibrinolytic impairment by increasing the thrombin levels and thus increasing the recently described thrombin-activable fibrinolysis inhibitor (TAFI).

Lipoprotein (a): its role in childhood thromboembolism.

PURPOSE: Elevated lipoprotein (a) [LP (a)] concentrations are independent risk factors of coronary heart disease or stroke in young adults. To clarify its role in childhood thromboembolism, Lp (a) was measured in 72 children with thromboembolism. METHODS: In addition to Lp (a), defects of the protein C anticoagulant system, antithrombin, and antiphospholipid antibodies were investigated in children with arterial (n = 36) or venous (n = 36) thrombosis. RESULTS: Enhanced Lp (a) >50 mg/dL was diagnosed in 8 out of 36 children with arterial and 5 out of 36 patients with venous thrombosis. Of the 72 children, 25 showed the factor V Leiden mutation, 10 showed protein C deficiency, 2 showed antithrombin deficiency, and 4 showed primary antiphospholipid syndrome. Three children with increased Lp (a) were heterozygous for the factor V Leiden mutation, and 1 girl showed additional protein C deficiency. CONCLUSIONS: Data of this study indicate that increased concentrations of Lp (a) play an important role in childhood thrombosis.

Arginine506 to glutamin mutation in the factor V gene in infancy and childhood: evidence of fibrinolytic impairment.

UNLABELLED: Resistance to activated protein C (APCR), in the majority of cases due to arginine506 (Arg506) to glutamine (Gln) mutation in the factor V gene, has emerged as the most important hereditary cause of venous thrombo-embolism. To determine to what extent this relatively common gene mutation influences the fibrinolytic system we investigated a population of APC resistant children (n = 65) in comparison with a control group of sex- and age-matched healthy children (n = 100). Compared to the controls, plasma levels of tissue-type plasminogen activator (t-PA), urokinase-type plasminogen activator (u-PA) and plasminogen activator inhibitor (PAI) 1 antigen, D-Dimer and enhanced thrombin generation were significantly (P < 0.0001) increased in children with the common factor V mutation. No difference was found between symptomatic and non-symptomatic children. Whether high concentrations of t-PA, u-PA and PAI 1 antigen can predict future vascular occlusion in children with APCR requires a more extensive multicentre study. CONCLUSION: Our data indicate that hypercoagulability in children with the Arg506 to Gln mutation in the factor V gene is mainly attributed to the genetic aetiology of the disease.

Elevated levels of soluble thrombomodulin in plasma from children with Arg 506 to Gln mutation in the factor V gene.

To find out to what extent the Arg506 to Gln mutation in the factor V gene affects the defence system against thromboembolism we investigated soluble thrombomodulin, protein C, protein S along with thrombin generation and D-dimer formation in 188 children. Children with the Arg506 to Gln mutation in the factor V gene (n = 48) showed significantly elevated thrombomodulin concentrations compared to nonaffected brothers and sisters (n = 50; p = 0.001) and age-matched healthy controls (n = 90; p < 0.0001). In addition, thrombin generation and D-dimer formation were significantly elevated in children with the mutation. In contrast, protein C and total protein S antigen levels were no different in the populations tested. Thus, with respect to thrombomodulin being a potent inhibitor of coagulation activation, the present data might be interpreted as a counterregulatory mechanism in infants and children with the Arg506 to Gln mutation in the factor V gene, maintaining the coagulation balance. The role of TM and other proteins involved in the coagulation balance in children and adults homozygous for the Arg506 to Gln mutation in the factor V gene remains to be clarified.

APC resistance in childhood thromboembolism: diagnosis and clinical aspects.

Few studies of activated protein C resistance (APCR) and thromboembolism in childhood have been published. In the majority of childhood thromboses reported, the factor V Leiden mutation was associated with venous thromboses; however, one case report and three studies described arterial thromboembolism in infants and children due to the common mutation in the factor V gene. In one neonate purpura fulminans occurred, and heparin-induced thrombocytopenia type II was additionally documented. Two case reports and seven of nine studies reported associated clinical conditions together with inherited coagulation disorders. In three studies homozygous patients were mentioned. There are few studies describing the interaction between APCR and coagulation or the fibrinolytic system in symptomatic and nonsymptomatic infants. Compared with healthy brothers or sisters and a healthy age-matched control group, thrombin generation, D-dimer, PAI-1 activity, and t-PA antigen were found clearly elevated in children with APCR. In addition, infants and children with the Arg506-to-Gln mutation in the factor V gene showed significantly increased thrombomodulin concentrations along with normal protein C activities compared with relatives and healthy controls. No difference was recorded in these studies between heterozygous infants and children without vascular occlusion and patients who previously had suffered from thromboembolism. Until long-term data are available for the treatment of patients with APCR, such children should be treated in the same way as patients with deficiencies of protein C, protein S, or antithrombin.

Inherited defects of the protein C anticoagulant system in childhood thrombo-embolism.

Childhood thrombo-embolism is mostly the result of inherited thrombophilia or vascular insults combined with risk factors such as peripartal asphyxia, fetopathia diabetica, exsiccosis, septicaemia, central lines, congenital heart disease, cancer, trauma, surgery or elevated antiphospholipid antibodies. Inherited thrombophilia includes mainly defects of the protein C pathway, resistance to activated protein C, protein C or protein S deficiency. Resistance to activated protein C, in the majority of cases caused by the point mutation Arg 506 Gln of the factor V gene, has emerged as the most important hereditary cause of thrombo-embolism in adults and children. However, since an acquired risk of thrombo-embolic complications frequently masks the inherited deficiency in affected children, children with thrombo-embolism should have adequate laboratory evaluation for inherited coagulation disorders, especially the protein C pathway. Until more data on childhood thrombo-embolism are available, treatment recommendations will continue to be extrapolated from guidelines for adults.

Thromboembolism and resistance to activated protein C in children with underlying cardiac disease.

OBJECTIVES: In the majority of cases, resistance to activated protein C is caused by the point mutation Arg506 to Gln in the factor V gene and has emerged as the most important hereditary cause of thromboembolism. METHODS: To determine to what extent resistance to activated protein C was present in children with thromboembolism and underlying cardiac disease, its occurrence was retrospectively investigated. By using a method based on activated partial thromboplastin time, with DNA technique derived from the polymerase chain reaction, we investigated nine children with underlying cardiac disease in whom thromboembolism had previously occurred. RESULTS: Heterozygous Arg506-to-Gln mutation in the factor V gene was diagnosed in five of the nine children investigated. In addition, protein C type I deficiency w as found in three patients, and two of the nine children showed increased lipoprotein (a) plasma values. Risk factors were present in all children with symptoms. CONCLUSIONS: These data indicate that deficiencies in the protein C anticoagulant pathway are likely to play an important role in the early manifestation of thromboembolism in children with underlying cardiac disease.

Ischaemic stroke in infancy and childhood: role of the Arg506 to Gln mutation in the factor V gene.

Dahlbäck et al. recently described in vitro resistance to the anticoagulant response of activated protein C (APC), in the majority of cases associated with the Arg506 to Gln point mutation in the factor V gene in thrombophilic patients. To determine to what extent this common gene mutation affects the risk of childhood stroke, its occurrence was prospectively investigated in a population of children with ischaemic stroke. Over a 2-year period the Arg506 to Gln mutation, factor V, protein C, protein S, antithrombin, antiphospholipid antibodies and lipoprotein (a) [Lp(a)] were measured in 14 infants and children with acute ischaemic stroke. Heterozygous factor V Leiden mutation (n = 4), homozygous factor V Leiden mutation (n = 1), protein C deficiency type I (n = 3) and increased Lp(a) (n = 2) were diagnosed in the children investigated. Seven of 14 patients showed an underlying disease and additionally risk factors were present in nine of 14 children. Data of this study indicate that deficiencies in the protein C anticoagulant pathway play an important role in the aetiology of childhood stroke. However, additional triggering factors may promote early manifestation of thromboembolism in children with inherited defects of clotting inhibitors.

Left atrial thrombus in a 10-month-old boy--successful thrombolysis with recombinant tissue-type plasminogen activator after open-heart surgery: review of the literature.

A 10-month-old boy with major left atrial thrombus following cardiac surgery was treated with intravenously administered recombinant tissue-type plasminogen activator (rt-PA; Actilyse, Thomae-Behring, Germany). The left atrial thrombus was diagnosed by Doppler echocardiography 8 days after complete correction of a ventricular septal defect. rt-PA therapy was administered over a 10-day period. Significant hemopericardium occurred 50 h after the start of thrombolytic therapy. rt-PA infusion was discontinued for 20 h to insert a pericardial drainage. The initial rt-PA dose was 0.1 mg/kg over 10 min followed by a continuous daily infusion of 1.7 mg/kg together with low-dose heparin. Thrombolytic therapy was restarted 20 h after pericardial drainage was inserted. The daily rt-PA dose was gradually raised to 3 mg/kg (total dose: 18 mg/kg). On day 7 and 8 a clear decrease in P-plasminogen and P-antithrombin occurred, requiring additional fresh frozen plasma and P-antithrombin concentrate substitution. One day later, without further side effects, complete thrombolysis occurred. Although hemopericardium demanded discontinuation of thrombolytic therapy, rt-PA administration, closely monitored by Doppler echocardiography, was continued, leading to complete thrombolysis of the left atrial thrombus in the early postoperative period. We consider the literature dealing with rt-PA thrombolysis in infancy we discuss this case report.

Plasma thrombomodulin concentrations in infants and children undergoing cardiac catheterization.

Circulating plasma thrombomodulin (TM) is an endothelial cell marker which may reflect endothelial injury. To find out to what extent diagnostic cardiac catheterization irritates vascular endothelium we conducted a prospective study in 91 children. Soluble TM concentrations, along with thrombin generation, were measured before, at the end of and 24 hours after cardiac catheterization. Compared to starting values, TM concentrations showed a clearly significant increase at the end of cardiac catheterization and returned to pretreatment values 24 hours later. Thrombin generation followed a similar pattern. Five out of the 91 children demonstrated resistance to activated protein C (APCR). With respect to the remaining 86 children, all five APCR cases showed increased thrombomodulin concentrations along with enhanced thrombin generation. Data from this study indicate that increased TM concentrations after cardiac catheterization in children are a sign of short-term endothelial damage. Furthermore, together with enhanced thrombin generation, elevated plasma concentration of soluble TM may reflect this receptor's possible anticoagulant properties.