Search

The diagnosis of von Willebrand disease (VWD) remains difficult in a significant proportion of patients. A Spanish multicentre study investigated a cohort of 556 patients from 330 families who were analysed centrally. VWD was confirmed in 480. Next generation sequencing (NGS) of the whole coding VWF was carried out in all recruited patients, compared with the phenotype, and a final diagnosis established. A total of 238 different VWF mutations were found, 154 were not included in the Leiden Open Variation Database (LOVD). Of the patients, 463 were found to have VWF mutation/s. A good phenotypic/genotypic association was estimated in 96.5% of the patients. One hundred seventy-four patients had two or more mutations. Occasionally a predominant phenotype masked the presence of a second abnormality. One hundred sixteen patients presented with mutations that had previously been associated with increased von Willebrand factor (VWF) clearance. RIPA unavailability, central phenotypic results disagreement and difficult distinction between severe type 1 and type 3 VWD prevented a clear diagnosis in 70 patients. The NGS study facilitated an appropriate classification in 63 of them. The remaining seven patients presented with a VWF novel mutation pending further investigation. In five patients with a type 3 and two with a type 2A or 2B phenotype with no mutation, an acquired von Willebrand syndrome (AVWS) was suspected/confirmed. These data seem to support NGS as a first line efficient and faster paradigm in VWD diagnosis.

Background: Acute lymphoblastic leukemia (ALL) is the most frequent cancer in childhood. Although intensive chemotherapy has improved survival in those patients, important side effects, including hyperbilirubinemia, are frequent. Gilbert syndrome (GS) is a frequent condition that causes a reduction in glucuronidation and intermittent hyperbilirubinemia episodes. This could provoke a greater exposure to some cytotoxic agents used in ALL, increasing the risk of toxicity. On the other hand, unexplained hyperbilirubinemia could lead to unnecessary modifications or even treatment withdrawals, which could increase the risk of relapse, but data regarding this in ALL pediatric population are scarce., Methods: Retrospective study to analyze toxicity, outcome and treatment modifications related to GS in children diagnosed with ALL., Results: A total of 23 of 159 patients were diagnosed with GS. They had statistically higher hyperbilirubinemias during all treatment phases (P < 0.0001) and a slower methotrexate clearance when it was administered during a 24-hr infusion at high doses (patients with GS: 74 hr ± 19 vs. patients without GS: 64 hr ± 8; P <  .002). However, no relevant toxicity or delays in treatment were found in them. Finally, changes in treatment due to hyperbilirubinemia were only done in 5 patients with GS., Conclusions: Differences in outcome were not found in patients with GS. Universal screening for GS appears to be not necessary in pediatric patients with ALL. However, when hyperbilirubinemia is observed, it must be rule out in order to avoid unnecessary changes in treatment., (© 2015 Wiley Periodicals, Inc.)

Intriguing experimental results raised the question about the fundamental mechanisms governing the electron-hole coupling induced bipolar thermal conduction in semiconductors. Our combined theoretical analysis and experimental measurements show that in semiconductors bipolar thermal transport is in general a "conductivity-limiting" phenomenon, and it is thus controlled by the carrier mobility ratio and by the minority carrier partial electrical conductivity for the intrinsic and extrinsic cases, respectively. Our numerical method quantifies the role of electronic band structure and carrier scattering mechanisms. We have successfully demonstrated bipolar thermal conductivity reduction in doped semiconductors via electronic band structure modulation and/or preferential minority carrier scatterings. We expect this study to be beneficial to the current interests in optimizing thermoelectric properties of narrow gap semiconductors.

Introduction: Human parainfluenza virus type 3 (HPIV-3) causes significant morbimortality in immunocompromised patients. Outbreaks of severe pneumonitis have been previously described in this setting., Materials and Methods: Retrospective observational study in children diagnosed with acute leukemia and a documented HPIV-3 infection in the context of a nosocomial outbreak occurred in a single center., Result: During summer 2012, an HPIV-3 infection was detected in six hospitalized children with acute leukemia. All the patients had respiratory symptoms and one of them suffered from parotitis., Conclusion: Early diagnoses using multiplex real-time polymerase chain reaction (PCR) let us control this outbreak. A phylogenetic analysis confirmed person-to-person transmission of a single HPIV-3 variant.

Central venous catheter (CVC) removal is indicated when persistent catheter-related bloodstream infection (CRBSI) occurs. This is a retrospective study to analyze the use of linezolid as a salvage therapy for CRBSIs due to coagulase-negative Staphylococci in children diagnosed with acute leukemia. Seven treatment courses of linezolid were administrated to six patients with port-type-CRBSI after non-effective intravenous vancomycin or teicoplanin treatment. Simultaneous lock and systemic therapy with linezolid avoided the removal of port-type-CVC in all cases. Treatment with linezolid was an alternative to catheter removal in these patients. Prospective studies are needed to confirm linezolid effectiveness as a salvage treatment in CRBSI., (Copyright © 2013 Wiley Periodicals, Inc.)

The use of intensive chemotherapy and central devices has improved patients survival, but it is associated with catheter-related blood-stream infections (CRBSI). An educational program was instituted for preventing CRBSI occurrence in acute leukemia pediatric patients having totally implanted central devices. The Centers of Disease Control and Prevention criteria were used as definition for CRBSI. Data collected were age, sex, diagnosis, chemotherapy, inpatient versus outpatient, microbiological data, risk factors, social risk score, and treatment performed. CRBSI rate decreased from 6.7 to 3.7/1000 catheter-days with preventive measures (P=0.05). A further decrease to 1.5/1000 catheter-days was reached after the intensification of the educational program (P=0.01). Severe neutropenia at the time of catheter insertion was related to CRBSI and to infection recurrence (P<0.05). Most of the episodes occurred during induction chemotherapy. Thirty-six CRBSI episodes occurred in 25 of 73 patients. The most frequent microorganism isolated was Staphylococcus spp. Antibiotherapy was successful in 83.3% of episodes. Six patients needed a central venous access device replacement. Our intervention program was successful to decrease the CRBSI rates and its intensification allowed a further decrease, approaching reported rates in this setting. Severe neutropenia at the time of central venous access device insertion was related to CRBSI occurrence and recurrence.

Immune tolerance induction (ITI) can overcome inhibitory factor VIII (FVIII) antibodies in haemophilia A patients receiving FVIII replacement therapy. The objective was to evaluate the use of sucrose-formulated, full-length recombinant FVIII (rFVIII-FS) for ITI therapy. Patients (<8 years at ITI start) with severe haemophilia A and a peak inhibitor titre >5 Bethesda units (BU) who underwent ITI with any rFVIII-FS dose for ≥ 9 months (or until success) were eligible for this retrospective study. Efficacy analyses included descriptions of ITI treatment regimens and outcomes; ITI success was determined solely at the discretion of the investigator. Safety analyses included assessment of adverse events. Of 51 enrolled patients, 32 [high dose (≥ 85 IU kg(-1) day(-1)), n = 21; low dose, n = 11] were eligible for analysis. ITI was successful in 69% (22/32) of patients (high dose, 66.7%; low dose, 72.7%) after a median of 1.4 years (range, 0.1-3.6 years). Influencing factors for ITI success were start of ITI <1 year after inhibitor detection and an inhibitor titre <10 BU at ITI start. All patients successfully tolerized with ITI continued to receive rFVIII-FS prophylaxis as maintenance therapy, with no inhibitor recurrence from the end of ITI until study enrolment. Use of rFVIII-FS for ITI was effective and well tolerated; success rates were similar to those in published studies., (© 2013 Blackwell Publishing Ltd.)

This study describes a cblE type of homocystinuria associated with haemolytic-uremic syndrome (HUS) features. We report on a male infant aged 43 days presenting with failure to thrive, hypotonia, pancytopaenia, HUS symptoms (microangiopathic haemolytic anaemia and thrombocytopaenia with signs of renal involvement) and fatal evolution. An underlying cobalamin disorder was diagnosed after a bone marrow examination revealed megaloblastic changes associated with hyperhomocysteinaemia. An urinary organic acid analysis revealed normal methylmalonic acid excretion. The cblE diagnosis was confirmed with a complementation analysis using skin fibroblasts and genetic studies of the MTRR gene. The patient treatment included parenteral hydroxocobalamin, carnitine, betaine and folinic acid, but there was no response. After the autopsy, the histopathological examination of the kidneys showed marked myointimal proliferation and narrowing of the vascular lumen. The central nervous system showed signs of haemorrhage that affected the putamen and the thalamus; diffuse white matter lesions with spongiosis, necrosis and severe astrogliosis were also observed. Microangiopathy was observed with an increase in vessel wall thickness, a reduction of the arterial inner diameter and capillary oedema. The signs of necrosis and haemorrhage were detected in the cerebellum, the cerebellar peduncles, the tegmentum and the bulbar olives.In conclusion, cblE should be considered when diagnosing patients presenting with HUS signs and symptoms during the newborn period. Despite early diagnosis, however, the specific treatment measures were not effective in this patient.

Primary immune thrombocytopenia (ITP), formerly known as immune thrombocytopenic purpura, is a disease in which clinical and therapeutic management has always been controversial. The ITP working group of the Spanish Society of Paediatric Haematology and Oncology has updated its guidelines for diagnosis and treatment of ITP in children based on current guidelines, literature review, clinical trials and member consensus. The primary objective was to lessen clinical variability in diagnostic and therapeutic procedures in order to obtain best clinical results with minimal adverse events and good quality of life., (Copyright © 2010 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.)

Deep vein thrombosis (DVT) has an estimated annual incidence of 0.07/10,000 children. Early diagnosis suspicion in the emergency department is important because it is a serious disease that, if untreated, can lead to a postthrombotic disease or a pulmonary thromboembolism. We report 2 cases of DVT whose diagnosis was made in the pediatric emergency department. Case 1 is a 9-year-old boy, evaluated with corticodependent nephrotic syndrome, who presented with pain in the lower left limb and increase in size of 48 hours' evolution suggestive of DVT. The elevation of D-dimer in the blood analysis and images from the Doppler ultrasound confirmed the diagnosis. His clinical evolution was good after beginning treatment with low molecular weight heparin. Case 2 is a 16-year-old adolescent, mother of a 1-year-old infant, who took oral contraceptives and was an occasional smoker, showed increased size and had pain in the lower left limb of a few hours' evolution. Deep vein thrombosis was suspected, and the diagnosis was confirmed by Doppler ultrasound. The evolution was favorable after beginning treatment with low molecular weight heparin. Although DVT is rare in children, early detection is important, requiring a detailed case history in the presence of edematous, painful, and hot limbs that are keys to the diagnostic suspicion. The imaging test and the laboratory tests will confirm the diagnosis, and anticoagulant treatment will prevent complications.

Pandemic influenza A (2009-H1N1) usually results in mild clinical illness, but in some individuals it can be life-threatening. There are no reports of this disease among paediatric patients with acute lymphoblastic leukaemia (ALL). We report ten consecutive patients with ALL and pandemic influenza treated in a single institution. Median age was 7 years (range: 3-12). All were treated with oseltamivir. There were no deaths. Two patients under intensive chemotherapy developed pneumonia and one required ventilatory support. ALL patients under maintenance treatment had mild disease. In conclusion, in our series only patients under intensive treatment developed a moderate to severe disease.

Idiopathic hypereosinophilic syndrome (HES) in children is a very rare disorder; certain clinical differences with adult HES have been described, with no pediatric case with the imatinib-responsive FIP1L1-PDGFRA fusion gene reported to date. The authors describe the clinical course of three children with HES in whom FIP1L1-PDGFRA fusion gene was studied and report the first child with this rearrangement.

Flow cytometry methods currently used for measuring neutrophil activation involve sample manipulation, which may result in cellular depletion and artifactual activation. To design a new methodology for measurement of neutrophil activation with minimal sample manipulation. Oxidative burst and CD 11b neutrophil expression were simultaneously assessed by a new no-lyse no-wash technique and a standard lyse-method in 10 pediatric patients with recurrent infections and two patients with chronic granulomatous disease (CGD). The new technique was based on nucleic acid staining to discriminate erythrocytes and debris without requiring physical separation. Both methods served equally to confirm or eliminate the diagnosis of CGD and leukocyte adhesion deficiency type 1. The values of baseline CD11b and oxidative burst obtained using the lysis method were significantly higher than those obtained by the no-lyse no-wash method. After activation, the lysis method resulted in higher neutrophil depletion (41%vs. 19%, P = 0.03). When compared with standard methods, neutrophil activation assessment by a no-lyse no-wash method resulted in lower neutrophil depletion and differences in oxidative burst and CD11b neutrophil values.

Purpura fulminans (PF) is an infrequent complication of varicella characterized by the progressive development of purpuric or painful ecchymotic lesions associated with biochemical alternations typical of consumption coagulopathy. Activation of coagulation is due to a marked and prolonged decrease in protein S, which is probably secondary to the formation of antiprotein S antibodies. The mechanism responsible for the synthesis of these autoantibodies is unknown. We present three cases of postvaricella PF and review the clinical and biochemical characteristics of this entity, as well as current diagnostic and therapeutic recommendations.

Introduction: Venous thrombosis is infrequent in paediatrics. A lot of prothrombotic risk factors have been described. Disturbances of coagulation are present in more than half of children with stroke. Leiden V factor mutation is emphasized as one of the most common genetic cause of deep venous thrombosis in Caucasian children and adults, which represents 20-25%, depending on series., Case Report: Two years-old girl with hypoxic-ischemic disease and West syndrome, which presents a deep venous thrombosis in both legs. This evolved to gangrene, requiring surgical exceresis of scar and amputation of 2nd, 3rd and 4th fingers of left foot. She also presented a right frontoparietal intraparenchima haemorrhagic stroke with tetraventricular bleeding and hydrocephalus. It required an external ventricular derivation and later a Ventricular-peritoneal valve., Conclusions: The coagulation study confirmed the Leiden V factor mutation in our patient. Later studies showed the same mutation in the father. The risk of recurrence and the severity of venous thrombosis indicate life antiaggregant treatment, currently maintained with aspirin.

Autoimmune hemolytic anemia (AIHI) is an infrequent disease in the pediatric age group. Its diagnosis is given by the direct antiglobulin test (DAT) or Coombs' test, which determines which type of globulin (IgG or complement) is the cause of the hemolysis. The type of globulin involved determines the etiology of AIHI, which is usually confirmed by positive results of other laboratory investigations such as cold agglutinin determination or the Donath-Landsteiner test. We present three cases of AIHI. DAT was positive to complement with diverse etiology: warm antibody with IgG-negative DAT, cold agglutinins associated with infectious mononucleosis, and Doth-Landsteiner antibodies. In all patients, empirical treatment with corticosteroids was initiated. The treatment was withdrawn or continued, depending on the final etiology of AIHI.

Case Report: Girl, aged 4, without antecedents who was admitted to our hospital for drowsiness and progressive sensorial depression. Within 24 hours the clinical picture deteriorated with partial seizures of the right hand side of the body and right hemiparesis. A brain CAT scan showed a left temporoparietal parenchymatous haematoma with collapse of the left lateral ventricle and moderate obliteration of the basal cisterns. MR angiography and cerebral arteriography displayed images that were compatible with thrombosis of the superior sagittal, the left transverse and the sigmoid sinuses. The patient was heterozygotic for the G A mutation in position 20210 of the prothrombin gene, which is linked with a high risk of thrombosis. She was given heparin intravenously, but continued to display endocranial hypertension and tissue ischemia with partial response to hyperosmolar agents and barbituric coma. She was therefore submitted to selective catheterization of the superior sagittal sinus and continuous local fibrinolysis with urokinase for 72 hours. The outcome was satisfactory, with repermeabilisation of the thrombosed sinuses and a good clinical response with no complications. At present the patient has functional paresis of the right hand and receives treatment with oral anticoagulants., Conclusions: We advocate the use of early local fibrinolytic treatment with urokinase in children affected by thrombosis of the venous sinuses who do not respond to treatment with sodium heparin. We consider it necessary to include the molecular study of the G20210A mutation of the prothrombin gene in screening for prothrombotic risk factors in small children

Objective: Thrombotic thrombocytopenic purpura (TTP) or Moschovitz' syndrome is rare and is even rarer in childhood. Clinically, it is characterized by microangiopathic hemolytic anemia, thrombocytopenia, neurologic abnormalities, fever and renal dysfunction. The etiology is still unknown, although different factors such as large von Willebrand factor multimers and prostacyclin have been implicated. The acute form is more frequent, and in most cases the course is fulminant if treatment is not initiated. Laboratory data typically reveal hemolytic anemia, with schistocytes on the peripheral smear, diminished serum haptoglobin, and thrombocytopenia., Material and Methods: We present the clinical cases of two children, aged 4 and 7 respectively, with TTP, but with different evolution and treatment. Evolution was favorable in both patients. The first child recovered spontaneously. In the second plasmapheresis was required and produced remission of all the symptomatology. Normality has been maintained for 36 and 24 months respectively, and the children have presented no clinico-biological alterations.