Publications by authors named "Clay Cohen"

Objective: To describe the incidence, clinical characteristics, and long-term outcomes of cerebral sinus venous thrombosis in children with acute lymphoblastic leukemia.

Methods: This was a retrospective cohort study comprising pediatric patients with newly diagnosed or first-relapse acute lymphoblastic leukemia who developed cerebral sinus venous thrombosis at Texas Children's Hospital from 2002 to 2019.

Results: Nineteen cases (1.

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Neonatal and infant aortic thrombosis is a rare albeit life-threatening thrombotic event, particularly seen in premature infants with an arterial catheter in place. We describe our institutional experience and approach to the management of 11 infants with occlusive or nearly occlusive aortic thrombosis. We observed at least partial thrombus resolution in all patients.

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Background: Comprehensive guidelines for the management of iron deficiency anemia (IDA) in adolescents with heavy menstrual bleeding (HMB) presenting to the emergency department (ED) are lacking, leading to variability in care. We aimed to standardize the evaluation and management of these patients through the development and implementation of an evidence-based algorithm using quality improvement methodology.

Methods: Baseline data of the target population identified variability across four key measures of clinical management: therapy choice and administration, laboratory evaluation, hematology service consultation, and patient disposition.

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Iron deficiency (ID) is a common and challenging problem in adolescence. In order to prevent, recognize, and treat ID in this age range, it is critical to understand the recommended daily intake of iron in relation to an adolescent's activity, dietary habits, and basal iron losses. Adolescents following vegetarian or vegan diets exclusively rely on plant-based, nonheme iron, which has decreased bioavailability compared with heme iron and requires increased total iron intake.

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For infants that present with intracranial hemorrhage in the setting of suspected abusive head trauma (AHT), the standard recommendation is to perform an evaluation for a bleeding disorder. Factor XIII (FXIII) deficiency is a rare congenital bleeding disorder associated with intracranial hemorrhages in infancy, though testing for FXIII is not commonly included in the initial hemostatic evaluation. The current pediatric literature recognizes that trauma, especially traumatic brain injury, may induce coagulopathy in children, though FXIII is often overlooked as having a role in pediatric trauma-induced coagulopathy.

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Iron-deficiency anemia occurs most commonly in young children due to a low-iron diet and adolescent girls due to menstrual blood loss. However, children with gastrointestinal conditions such as intestinal failure, inflammatory bowel disease, celiac disease, and/or other chronic conditions, including chronic kidney disease and heart failure, also commonly have iron deficiency. Many patients with classic iron-deficiency anemia will improve with oral iron therapy.

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Introduction: Diagnosing von Willebrand Disease (VWD) in adolescent females is challenging as menstruation and physiologic stress elevate von Willebrand factor (VWF) laboratory values.

Aim: To develop a VWF prediction model for adolescent females based on initial VWF results.

Methods: We identified female patients aged 9 to 21 years with any VWF laboratory test over a 5-year period (2017-2021) at any Texas Children's Hospital facility.

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The outcomes and characteristics of acquired thrombotic thrombocytopenic purpura (TTP) in adolescents is poorly understood due to an absence of studies focused on this population. To better understand the life-threatening disorder in this age, we performed an analysis of adolescent patients (ages 10-21) with TTP in the Pediatric Health Information Systems database from 2009 to 2020. The primary outcomes evaluated were in-hospital mortality and rate of TTP relapse.

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Coronavirus disease 2019 (COVID-19) infection in children has been associated with thrombosis, though few cases of COVID-associated pulmonary embolism (PE) have been described. We performed a retrospective review of the nine cases of COVID-19-associated PE during the B.1617.

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The mRNA COVID-19 vaccine and COVID-19 infection caused by the SARS-CoV-2 virus may be immunologic triggers for the development of thrombotic thrombocytopenic purpura (TTP). There is not yet literature that discusses TTP induced by COVID-19 vaccination or infection in pediatric or adolescent patients. We describe three adolescents presenting with TTP (both de novo and relapsed disease) following administration of the Pfizer COVID-19 vaccine or after COVID-19 infection.

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In a previous study, we reported that human endothelial cells (ECs) express and produce their own coagulation factors (F) that can activate cell surface FX without the additions of external proteins or phospholipids. We now describe experiments that detail the expression and production in ECs and fibroblasts of the clotting proteins necessary for formation of active prothrombinase (FV-FX) complexes to produce thrombin on EC and fibroblast surfaces. EC and fibroblast thrombin generation was identified by measuring: thrombin activity; thrombin-antithrombin complexes; and the prothrombin fragment 1.

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Real-world data describing emicizumab prophylaxis in pediatric hemophilia A is limited with current literature providing a heterogenous approach to procedural management. We performed a retrospective review on the 28 patients who have been treated with emicizumab prophylaxis at Texas Children's Hospital from 2018 to 2021. After starting emicizumab, the mean annualized bleeding rate reduced from 3.

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Article Synopsis
  • COVID-19 is generally mild in children, but it can lead to serious thrombotic complications, particularly in cases of multisystem inflammatory syndrome in children (MIS-C).
  • A study of 853 hospitalized children showed a higher incidence of thrombosis in those with MIS-C (6.5%) compared to those with COVID-19 (2.1%) and asymptomatic cases (0.7%).
  • Key risk factors for thrombosis included being 12 years or older, having cancer, having a central venous catheter, and being diagnosed with MIS-C; those with thrombotic events also had a significantly higher mortality rate.
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Effective treatment for acute, extensive, symptomatic lower extremity (LE) thrombosis involves thrombolysis in addition to anticoagulation. There is limited available data on the outcomes and safety of thrombolysis to help guide its use in pediatrics and young adults. A retrospective study of children and young adults (<21 years of age) that received catheter directed thrombolysis (CDT) for LE and inferior vena cava (IVC) thrombosis was performed over a 5-year span at a pediatric tertiary care center.

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Objective: To describe the clinical characteristics, outcomes, and adverse events of treatment for symptomatic infant catheter-related arterial thrombosis.

Study Design: Single-center retrospective medical record review of 99 infants (age <365 days) with catheter-related arterial thrombosis, either following indwelling arterial catheter placement or cardiac catheterization, who were treated with anticoagulation over an 8-year span at a pediatric tertiary care center. Outcomes measured include thrombosis progression, bleeding events, and thrombus resolution following the treatment period.

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May-Thurner syndrome (MTS) predisposes individuals to develop lower extremity deep venous thrombosis (DVT) because of compression of the left common iliac vein. Diagnosis of the anatomic obstruction is critical for effective therapy, as treatment by interventional radiology is often required in addition to anticoagulation to prevent thrombus progression and recurrence. The authors performed a retrospective review of adolescent patients who presented with MTS-associated DVT at a pediatric tertiary care center from 2009 to 2018 to assess for delays in MTS diagnosis after the presentation.

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Human endothelial cells (ECs) synthesize, store, and secrete von Willebrand factor multimeric strings and coagulation factor (F) VIII. It is not currently known if ECs produce other coagulation factors for active participation in coagulation. We found that 3 different types of human ECs in primary culture produce clotting factors necessary for FX activation via the intrinsic (FVIII-FIX) and extrinsic (tissue factor [TF]-FVII) coagulation pathways, as well as prothrombin.

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Article Synopsis
  • Cerebral cavernous malformation 3 (CCM3) is a brain vascular disorder caused by mutations in the PDCD10 gene, leading to slow-flow lesions in the brain.
  • An 8-month-old patient with seizures and brain abscesses was diagnosed with a PDCD10 variant, marking one of the youngest reported cases of CCM3.
  • The patient experienced significant blood-related complications (neutropenia and thrombocytopenia) and eventually developed B acute lymphoblastic leukemia, suggesting that the PDCD10 variant could impact both blood cell formation and brain cell migration.
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Introduction: In patients who are immunocompromised, fever may indicate a life-threatening infection. Prompt time to antibiotic administration in febrile patients at risk for neutropenia has been identified by national and international panels as a key benchmark of quality care in emergent situations. A quality improvement initiative to improve health care provided in a pediatric emergency department (ED) is described.

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