Inherited coagulation disorders in Turkish children: A retrospective, single-center cohort study.

OBJECTIVE: This study aims to investigate the distribution, clinical characteristics and outcome of inherited coagulation disorders (ICD) in Turkish children. SUBJECTS AND METHODS: Data from all children (age<18 years) with ICD examined in our center were retrospectively reviewed. RESULTS: There were 403 children with ICD (233 males and 170 females) with a median age of four years at diagnosis. The percentages of von Willebrand disease (vWd), hemophilia and rare bleeding disorders (RBD) were 40 %, 34 % and 26 %, type-1, type-2 and type-3 vWd were 63 % 17 % and 20 %, hemophilia A and B were 84 % and 16 %, and severe, moderate and mild hemophilia were 48 %, 30 % and 22 %, respectively. Factor VII and FXI deficiencies were the most prevalent, comprising 56 % and 22 % of all children with RBD, respectively. Parental consanguinity rates were 72 % in type-3 vWd and 61 % in severe RBD. The overall prevalence of gastrointestinal bleedings was 4.5 % (18/403), intracranial bleeding (ICB) was 4.96 % (20/403), mortality from ICB was 30 % (6/20) and the overall mortality rate was 1.49 % (6/403). No life-threatening bleeding was seen during regular prophylaxis. Chronic arthropathy prevalence in severe hemophilia was 8 % with primary prophylaxis and 53 % with demand therap. Inhibitor prevalence was 14 % in hemophilia-A and 5 % in hemophilia-B. CONCLUSIONS: These data show that vWd is the most common ICD, type-3 vWd and RBD are prevalent due to frequent consanguineous marriages and diagnosis of ICD is substantially delayed in Turkish children. Prophylactic replacement therapy prevents occurrence of life-threatening bleedings and reduces the development of hemophilic arthropathy.

Hematologic Findings of Inherited Metabolic Disease: They are More Than Expected.

Inherited metabolic diseases are pathologic conditions that generally develop as a result of impairment of the production or breakdown of protein, carbohydrate, and fatty acids. Early determination of hematological findings has a positive effect on the prognosis of metabolic diseases. Three hundred eighteen patients who were being followed-up within the previous 6 months at Department of Pediatric Nutrition and Metabolism, Gazi University, Turkey, were included in the study. The hematological findings were classified under 7 main groups: anemia of chronic disease, iron deficiency anemia, vitamin B12 deficiency anemia, hemophagocytosis, leukocytosis, and thrombocytosis. Nine hundred twenty-two hematological examinations of the 319 patients were included in the study, and 283 hematological findings were determined, 127 anemia of chronic disease, 81 iron deficiency anemia, 56 cytopenia, and 4 vitamin B12 deficiency anemia. Leukocytosis (n=1), thrombocytosis (n=5), and hemophagocytosis (n=9) were also observed. It was determined that, although anemia of chronic disease and nutritional anemia are the most common hematological findings, these may be diagnosed late, whereas neutropenia, thrombocytopenia, pancytopenia, and hemostasis disorders may be diagnosed earlier. Our study is the most comprehensive one in the literature, and we think it would positively contribute to the monitoring and prognosis of congenital metabolic diseases.

Association of CYP3A5 Expression and Vincristine Neurotoxicity in Pediatric Malignancies in Turkish Population.

Vincristine is a widely used chemotherapeutic agent in the treatment of childhood malignancies. Neuropathy is the most common adverse effect. CYP3A4 and CYP3A5 enzymes of cytochrome p450 enzyme system are responsible in vincristine metabolism. Genetic polymorphism may alter the vincristine metabolism and the neurotoxicity rate. In this study, distribution of CYP3A5 alleles among Turkish children with malignancies, relation between CYP3A5 genotype and neurotoxicity rates, as well as severity and duration of neuropathy and total vincristine doses were investigated. Patient group consisted of 115 patients (age, 1 to 17 y) with acute lymphoblastic leukemia and solid tumors, who were treated with vincristine consisting chemotherapy protocols. Control group consisted of 50 children without any neurological symptom or disorders. All patient files were reviewed for presence and severeness of neurotoxicity symptoms. Blood samples were obtained and CYP3A5 genotypes were analyzed. Neurotoxicity occurred in 20.8% of patients. Although it was found to occur more frequently after 4 doses of vincristine, and rates were higher in the low-dose vincristine group suggesting other contributing factors. Although neurotoxicity rate in the CYP3A5*1/*3 genotype was 17.6%, it was 21.6% in the CYP3A5*3/*3 genotype and the difference was not statistically significant (P<0.05). This study suggested that vincristine-related neurotoxicity is dose-independent and genotype is not the only causative factor in the occurrence of neurotoxicity in these patients.

Successful total hip replacement with sequential administration of bypassing agents in an adolescent boy with hemophilia A and high inhibitor titers.

: There are only a few reports of total hip replacement in patients with hemophilia A and inhibitors. We performed total hip replacement in an 18-year-old adolescent boy who had high inhibitor titers since infancy. Recombinant factor VIIa (NovoSeven) was used as a bypass agent during the surgery. There was no excessive introperative bleeding; however, postsurgical bleeding occurred and was controlled by sequential administration of recombinant factor VIIa and activated prothrombin complex concentrate (FEIBA). This is the first report of this treatment modality in such a major surgery. Sequential bypassing agent therapy can be effective for treating refractory bleeding in hemophilia patients who have high inhibitor titers but require major surgery.

Influence of Folate-Related Gene Polymorphisms on High-Dose Methotrexate-Related Toxicity and Prognosis in Turkish Children with Acute Lymphoblastic Leukemia.

OBJECTIVE: High-dose methotrexate (HD-MTX) is widely used in the consolidation phase of childhood acute lymphoblastic leukemia (ALL), but the roles that polymorphisms in folate-related genes (FRGs) play in HD-MTX toxicity and prognosis in children with ALL are not understood. The aims of this study were to investigate the frequencies of polymorphisms in the genes for thymidylate synthase (TS), methionine synthase reductase (MTRR), and methylene tetrahydrofolate reductase (MTHFR) in Turkish children with ALL and to assess associations between these polymorphisms and HD-MTX-related toxicity and leukemia prognosis in this patient group. MATERIALS AND METHODS: FRG polymorphisms were assessed by real-time polymerase chain reaction. Survival status, MTX levels, and toxicity data were retrieved from 106 patients' charts. RESULTS: The allele frequencies for the FRG polymorphisms were as follows: TS 2R 41.0%, 3R 57.0%, and 4R 2.0%; MTRR 66A 42.4% and 66G 57.6%; MTHFR 677C 59.3% and 677T 40.7%; and MTHFR 1298A 58.1% and 1298C 41.9%. At the 48th hour of HD-MTX infusion, serum MTX was significantly higher in patients who had TS 2R/3R/4R variants as compared to those with wild-type TS (p<0.05). No significant differences were detected with respect to event-free survival or toxicity between wild-type and other FRG variants. CONCLUSION: The frequencies of FRG polymorphisms in Turkish children with ALL are similar to those reported in other Caucasian populations. This is the first published finding of the TS 3R/4R variant in the Turkish population. The results indicate that HD-MTX can be tolerated by leukemic children with some polymorphic variants of FRG; thus, it may prevent future risk of leukemic relapse.

The effect of CYP2C9 and VKORC1 genetic polymorphisms on warfarin dose requirements in a pediatric population.

OBJECTIVE: The aim was to investigate the frequency of genetic polymorphisms of cytochrome P4502C9 (CYP2C9) and vitamin K epoxide reductase complex subunit1 (VKORC1) and determine the effect of these polymorphisms on warfarin dose requirements in pediatric patients. METHODS: Fifty-eight pediatric patients with cardiac disease, thrombophilia, or other conditions, taking a stable warfarin dose, aged 0.2-18 years, and with international normalized ratio (INR) between 2 and 3 and 149 healthy children as a control group were included in this prospective, observational study. Patients receiving drugs that interact with warfarin, having chronic liver or renal disease, obesity, or thyroid dysfunctions were excluded. Polymerase chain reaction (real time and restriction fragment length polymorphism) was used to analyze the CYP2C9*2, CYP2C9*3, and VKORC1 polymorphisms. The ideal warfarin dose was calculated according to the patient's age, height, and the presence of CYP2C9*2, CYP2C9*3, and VKORC1 genetic polymorphisms. The mean daily administered doses and ideal doses were compared. Analysis of variance, Student's t-test, logistic regression analysis, and Pearson's correlation analysis were used for statistical analyses. RESULTS: The frequency of the CYP2C9 and VKORC1 genetic polymorphisms was determined as CYP2C9*1/*1 (54.6%), *1/*2 (16.4%), *1/*3 (24.2%), *2/*3 (2.9%), *3/*3 (1.9%), wild-type VKORC1 (26.6%), heterozygote alleles (52.7%), and mutant alleles (20.8%). Patients with allelic variants were found to require lower warfarin doses, and a 64.5% correlation was found between the calculated ideal doses and the administered warfarin doses. CONCLUSION: Considering CYP2C9 and VKORC1 genetic polymorphisms prior to commencing warfarin treatment will make it easier to reach target INRs and reduce the rate of complications.

The Effect of Carbon Dioxide Insufflation Applied at Different Pressures and Periods on Thrombotic Factors.

The aim of this experimantal study which is applied on rats, is to determine the differences on the clotting factors over the application of low and high intraabdominal pressure (IAP) values in different periods of time in carbon dioxide (CO2) pneumoperitoneum. Thirty rats were randomized into five groups (n = 6): a control group (Group K) and 1 h and 6 mm Hg IAP (Group A), 2 h and 6 mm Hg IAP (Group B), 1 h and 12 mm Hg IAP (Group C) and 2 h and 12 mm Hg IAP were created with CO2 pneumoperitoneum (Group D). At the end of the experiment, plasma samples taken from subjects and fibrinogen, FII (prothrombin), FV, FVII, FVIII, FIX, FX, FXI, FXII, von willebrand's factor (vWF), ristocetin cofactor, protein C, protein S, antithrombin III (AT III) levels are studied. There were statistically significant differences in the mean levels of FII, FV, FVII, FVIII, FIX, FX, FXI, FXII, and protein S between the groups. A hypercoagulable state occurred with the following: increase in the coagulation parameters compared to the control group; increase in FVII in the group only Group C; decrease in AT III in all groups compared to the control group; decrease in protein C in the group only XII Group D compared to control group; decrease in protein S in all groups except group D compared to control group. CO2 insufflation predisposes to thromboembolic events both by inducing coagulation factors and by suppressing the fibrinolytic system contrary to the controversies in the literature.

Prognostic Factors and Long-Term Outcome in 52 Turkish Children With Hemophagocytic Lymphohistiocytosis.

OBJECTIVES: Hemophagocytic lymphohistiocytosis is a syndrome of pathologic immune activation that shares similar clinical and laboratory phenotypes with severe sepsis. Recent studies led to better recognition of hemophagocytic lymphohistiocytosis by clinicians, but no consensus exists on the criteria for high-risk patients. DESIGN: We retrospectively reviewed the medical records of patients diagnosed with hemophagocytic lymphohistiocytosis to analyze the risk factors associated with poor outcome. SETTING: Pediatric intensive care and hematology units of three tertiary hospitals in Turkey. PARTICIPANTS: Fifty-two children with hemophagocytic lymphohistiocytosis. INTERVENTIONS: None. MEASUREMENT AND MAIN RESULTS: There were a total of 52 children meeting the diagnostic criteria of Histiocytic Society. Of them, 28 (54%) had a primary hemophagocytic lymphohistiocytosis. Mutation studies were performed in 18 of 28 patients (65%). Fourteen of them had PRF1, STX11, STXBP2, and UNC13D mutations, and four had Rab27a and LYST mutations. The remaining 24 patients (46%) were defined as having secondary hemophagocytic lymphohistiocytosis. Twenty-one of them had infection-associated hemophagocytic lymphohistiocytosis, and three had lysinuric protein intolerance. The mortality rate was significantly higher in primary hemophagocytic lymphohistiocytosis (64%) than in secondary hemophagocytic lymphohistiocytosis (16%) (p < 0.05). There were no significant differences for survival rate between hemophagocytic lymphohistiocytosis 94 (44%) and hemophagocytic lymphohistiocytosis 2004 (64%) protocols (p > 0.05). Age below 2 years, hyperferritinemia, thrombocytopenia, high disseminated intravascular coagulation score at diagnosis, and no clinical response at 2 weeks of treatment were independent prognostic factors for poor prognosis. CONCLUSIONS: Our data suggest that disseminated intravascular coagulation score greater than or equal to 5 can be used in the definition of high-risk patients. Early recognition of poor risk factors has important prognostic and therapeutic implications.

Transcobalamin II Deficiency in Four Cases with Novel Mutations.

OBJECTIVE: Transcobalamin II deficiency is one of the rare causes of inherited vitamin B12 disorders in which the patients have characteristically normal or high vitamin B12 levels related to the transport defect of vitamin B12 into the cell, ending up with intracellular cobalamin depletion and high homocysteine and methylmalonic acid levels. MATERIALS AND METHODS: Herein, we describe the findings at presentation of four patients who were diagnosed to have transcobalamin II deficiency with novel mutations. RESULTS: These patients with transcobalamin II deficiency were found to have novel mutations, of whom 2 had the same large deletion (homozygous c.1106+1516-1222+1231del). CONCLUSION: Transcobalamin II deficiency should be considered in differential diagnosis of any infant with pancytopenia, failure to thrive, diarrhea, and vomiting.

Molecular basis and bleeding manifestations of factor XI deficiency in 11 Turkish families.

Factor XI (FXI) deficiency is an autosomal bleeding disorder characterized by variable bleeding tendency. In the present study, the gene encoding FXI (F11) was analyzed by direct sequencing in 33 individuals belonging to 11 unrelated Turkish families, and the bleeding tendency was quantitatively assessed by means of a bleeding questionnaire in 27 individuals with low FXI clotting activity and/or mutated F11 gene. We identified 10 distinct mutations (five missense, three nonsense and two splice site), four of which were novel. No mutation was found in one family. Of the four novel mutations, homozygosity for a c.89T>C (p.Phe30Ser) mutation and compound heterozygosity for a c.646G>A (p.Asp216Asn) mutation with the known c.403G>T (p.Glu135) type II Jewish mutation were associated with severe deficiency, whilst heterozygosity for the novel c.1655A>C (p.His552Arg) and c.1627G>A (p.Glu543Lys) mutations was associated with partial deficiency. p.Glu135 was found in 19% (5/27) of the mutated alleles. Bleeding score was positive in 57% (4/7) of individuals with severe and 39% (7/18) of those with partial deficiency. It was significantly correlated with clinical severity of bleeding (r = 0.43, P = 0.02), but not with FXI clotting activity (P > 0.05). There was no optimal cut-off level of the bleeding score that could predict FXI deficiency. We conclude that the spectrum of mutations found in this study reflects the genetic heterogeneity of FXI deficiency in the Turkish population. Quantitative assessment of the bleeding symptoms by a bleeding questionnaire seems to be useful for evaluating the severity of bleeding episodes, but it can not be recommended as a screening tool for FXI deficiency.

Evaluation of Pediatric Bleeding Questionnaire in Turkish Children With Von Willebrand Disease and Platelet Function Disorders.

The diagnosis of mild bleeding disorders is not easy as most of the "healthy" individuals also report bleeding symptoms. In order to get a precise bleeding history, Pediatric Bleeding Questionnaire (PBQ) has been developed. In our study, Turkish children diagnosed with Von Willebrand disease (VWD), platelet function defect (PFD), and healthy children without any symptoms (control group 1) and healthy children with symptoms but found hemostatically normal (control group 2) were analyzed with PBQ. The cut off level for "positive bleeding score" was found to be ≥2 (area under the curve [AUC]: 0.785, 95% confidence interval [CI]: 0.718-0.852). The sensitivity, specificity, positive predictive value, and negative predictive value of PBQ to define VWD versus control group 1 was 100%, 97.4%, 96.4%, and 100%; VWD versus control group 2 was 100%, 53.1%, 64.3%, and 100%; PFD versus control group 1 was 93.3%, 53.1%, 73.7%, and 85%; and PFD versus control group 2 was 93.3%, 53.1%, 73.7%, and 85%, respectively.

Severe Myelotoxicity Associated with Thiopurine S-Methyltransferase*3A/*3C Polymorphisms in a Patient with Pediatric Leukemia and the Effect of Steroid Therapy.

Myelosuppression is a serious complication during treatment of acute lymphoblastic leukemia and the duration of myelosuppression is affected by underlying bone marrow failure syndromes and drug pharmacogenetics caused by genetic polymorphisms. Mutations in the thiopurine S-methyltransferase (TPMT) gene causing excessive myelosuppression during 6-mercaptopurine (MP) therapy may cause excessive bone marrow toxicity. We report the case of a 15-year-old girl with T-ALL who developed severe pancytopenia during consolidation and maintenance therapy despite reduction of the dose of MP to 5% of the standard dose. Prednisolone therapy produced a remarkable but transient bone marrow recovery. Analysis of common TPMT polymorphisms revealed TPMT *3A/*3C.

Recombinant long-acting glycoPEGylated factor IX in hemophilia B: a multinational randomized phase 3 trial.

This multinational, randomized, single-blind trial investigated the safety and efficacy of nonacog beta pegol, a recombinant glycoPEGylated factor IX (FIX) with extended half-life, in 74 previously treated patients with hemophilia B (FIX activity ≤2 IU/dL). Patients received prophylaxis for 52 weeks, randomized to either 10 IU/kg or 40 IU/kg once weekly or to on-demand treatment of 28 weeks. No patients developed inhibitors, and no safety concerns were identified. Three hundred forty-five bleeding episodes were treated, with an estimated success rate of 92.2%. The median annualized bleeding rates (ABRs) were 1.04 in the 40 IU/kg prophylaxis group, 2.93 in the 10 IU/kg prophylaxis group, and 15.58 in the on-demand treatment group. In the 40 IU/kg group, 10 (66.7%) of 15 patients experienced no bleeding episodes into target joints compared with 1 (7.7%) of 13 patients in the 10 IU/kg group. Health-related quality of life (HR-QoL) assessed with the EuroQoL-5 Dimensions visual analog scale score improved from a median of 75 to 90 in the 40 IU/kg prophylaxis group. Nonacog beta pegol was well tolerated and efficacious for the treatment of bleeding episodes and was associated with low ABRs in patients receiving prophylaxis. Once-weekly prophylaxis with 40 IU/kg resolved target joint bleeds in 66.7% of the affected patients and improved HR-QoL. This trial was registered at www.clinicaltrials.gov as #NCT01333111.

The frequency of menorrhagia and bleeding disorders in university students.

STUDY OBJECTIVE: Menorrhagia is an important health problem in women of reproductive age. The aims of this study were to assess the prevalence of menorrhagia and hemostatic abnormalities associated with menorrhagia in university students. METHODS: The pictorial blood assessment chart (PBAC) was used to identify students with menorrhagia. Those with a PBAC score > 100 were examined by pelvic ultrasound and laboratory tests including complete blood count, levels of clotting factors, von Willebrand factor antigen, and ristocetin cofactor activity and Platelet Function Analyser-100 (PFA-100). Platelet aggregation was studied in students with prolonged PFA-100 closure time. RESULTS: Menorrhagia was identified in 82 (21.8%) of 376 students. Six of 82 students who had pelvic pathologies were excluded. Eleven (14.5%) of the remaining 76 students were found to have bleeding disorders, including von Willebrand disease in five (6.5%), platelet function disorder in four (5.2%), and clotting factor deficiencies in two (2.6%). CONCLUSIONS: Menorrhagia is a common but mostly unrecognized and untreated problem among university students. Underlying bleeding disorders are not rare and require comprehensive hemostatic evaluation for identification.

Leukocyte populations and C-reactive protein as predictors of bacterial infections in febrile outpatient children.

OBJECTIVE: Infections remain the major cause of unnecessary antibiotic use in pediatric outpatient settings. Complete blood count (CBC) is the essential test in the diagnosis of infections. C-reactive protein (CRP) is also useful for assessment of young children with serious bacterial infections. The purpose of the study was to evaluate leukocyte populations and CRP level to predict bacterial infections in febrile outpatient children. MATERIALS AND METHODS: The values of CBC by Cell-DYN 4000 autoanalyzer and serum CRP levels were evaluated in 120 febrile patients with documented infections (n:74 bacterial, n:46 viral) and 22 healthy controls. RESULTS: The mean CRP, neutrophil and immature granulocyte (IG) values were significantly higher in bacterial infections than in viral infections and controls (p<0.05). C-reactive protein was significantly correlated with neutrophil level in bacterial infections (r: 0.76, p<0.05). Specificity of IG was greatest at 93%, only a modest 56% for neutrophil and mild 18% for CRP, whereas 100% for combination of IG, neutrophil and CRP. CONCLUSION: Acute bacterial infection seems to be very unlikely in children with normal leukocyte populations and CRP values, even if clinically signs and symptoms indicate acute bacterial infections.

A novel mutation of ABCG5 gene in a Turkish boy with phytosterolemia presenting with macrotrombocytopenia and stomatocytosis.

Phytosterolemia is a rare autosomal recessive sterol storage disease caused by mutations in ABCG5 and ABCG8 genes. A 9-year-old Turkish boy who was presented with exclusively hematologic abnormalities had elevated plant sterol levels. Sequencing of ABCG5 and ABCG8 genes revealed a novel homozygous IVS10-1 G>T mutation in ABCG5 gene. Four of the 13 family members had xanthoma but they had neither hematologic abnormalities nor IVS10-1 G>T mutation. Ezetimibe therapy reduced plant sterol levels in association with marked clinical improvement. Plant sterol levels and ABCG5/ABCG8 genes should be analysed in patients with unexplained hemolytic anemia and macrothrombocytopenia.

The risk factors for thrombosis in children with acute lymphoblastic leukemia.

We aimed to scrutinize the risk factors for thrombosis in children with acute lymphoblastic leukemia treated with the Berlin-Frankfurt-Münster 95 protocol. The study population was 82 children younger than 16 years of age. The children were followed up for 10 years until January 2007. Thrombosis occurred in 10 (12%) of 82 patients during the treatment course, mainly after the M protocol. The most common risk factor was factor V Leiden (FVL; 15.6%). This was followed by methyleneterahydrofolate reductase (MTHFR; 9.3%), elevated lipoprotein (1.5%), and prothrombin (PT) 20210A (1.5%) in descending order. The risk of thrombosis was found to be significantly high in patients with FVL mutation (odds ratio = 7.1, 95% confidence interval = 1.6-30.5). The risk of thrombosis was not significant in patients with MTHFR and PT20210A mutation (P = .2). Age, catheter usage, FVL mutation, and prednisolone treatment are significant risk factors for thromboemboli occurrence.

Resolution of inflammatory colitis with pegfilgrastim treatment in a case of severe congenital neutropenia due to glucose 6 phosphatase catalytic subunit-3 deficiency.

Glucose 6 phosphatase catalytic subunit-3 (G6PC3) deficiency is a heterogenous disorder characterized by severe congenital neutropenia and a variety of extrahematopoietic manifestations. Inflammatory bowel disease like colitis is an uncommon complication of G6PC3 deficiency, described only in adolescent and adults. Herein, we describe inflammatory colitis in a 10-year-old girl with severe congenital neutropenia due to G6PC3 deficiency while she was on a high-dose filgrastim. Switching from filgrastim to (pegylated filgrastim) Pegfilgrastim led to rapid resolution of colitis, weight gain, and decreased infections. Pegfilgrastim seems to be a better remedy for treatment of G6PC3 deficiency complicated with inflammatory bowel disease.

Life-threatening agranulocytosis, anemia, and plasmacytosis after dipyrone use for fever in a child.

Dipyrone or metamizole Na (Novalgin) is commonly used as an antipyretic, analgesic, and spasmolytic agent in some parts of the world; however, it is banned in developed countries because of severe side effects. Here we present a case of a 4-year-old boy who developed life-threatening agranulocytosis, anemia, and marked plasmacytosis in his bone marrow after dipyrone use for fever, which resolved with steroid therapy.

Plasma levels and distribution of gene polymorphisms of factor VII in Turkish population.

Three factor VII (FVII) promoter haplotypes are associated with stratified plasma FVII levels. To our knowledge, this is the first study examining the distribution of FVII gene polymorphism and levels in Turkish population. The study population was classified into 3 groups according to the absence of coronary arterial disease and presence or absence of a history of myocardial infarction. It was found that the levels of FVII coagulant activity (FVIIc) were higher in the event group than that of the other groups. Participants with high FVIIc levels were found to have 2-fold increased risk for myocardial infarction. The alleles at the FVII loci in all cases are similar. In conclusion, our results indicate that FVIIc levels have an important predictive role in cardiovascular events. The distribution of FVII gene polymorphisms in the Turkish population shows significant differences when compared with European populations.