Transplant-associated TMA: the conundrum of diagnosis and treatment.

Transplant-associated thrombotic microangiopathy (TA-TMA) after hematopoietic cell transplantation is characterized by microangiopathic hemolytic anemia (MAHA) with persistent schistocytosis, elevated markers of hemolysis, thrombocytopenia, and microvascular thrombosis leading to ischemic injuries in the kidneys and other organs. The initial evaluation of the disease requires confirmation of non-immune MAHA and careful examination of known secondary causes of TMA. Due to increased likelihood of long-term renal failure and overall mortality, a rapid diagnosis and treatment of the underlying trigger is needed.

Management of neonatal and infant aortic thrombosis: A single-center case series.

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.

The Pathology of Pulmonary Disease After Pediatric Hematopoietic Stem Cell Transplantation.

Pulmonary complications continue to cause significant morbidity and mortality in posthematopoietic stem cell transplantation (HSCT) settings. The histopathology of pulmonary diseases in the post-HSCT context is poorly characterized, especially in the pediatric population. We sought to characterize the pathologic spectrum of pulmonary disease post-HSCT in a pediatric cohort.

Hospital acquired venous thromboembolism in children with sickle cell disease.

Sickle cell disease (SCD) is well recognized as a hypercoagulablestate, however, it remains unclear whether a subgroup of children with SCD at higher risk of venous thromboembolic event (VTE) during hospitalization may benefit from thromboprophylaxis. Our objectives were to describe the clinical characteristics, outcomes and recurrence of hospital acquired VTE in patients with SCD younger than 21 years. This was a single center retrospective study.

Implementing a Pediatric Pulmonary Embolism Response Team Model: An Institutional Experience.

Pulmonary embolism is increasing in prevalence among pediatric patients; although still rare, it can create a significant risk for morbidity and death within the pediatric patient population. Pulmonary embolism presents in various ways depending on the patient, the size of the embolism, and the comorbidities. Treatment decisions are often driven by the severity of the presentation and hemodynamic effects; severe presentations require more invasive and aggressive treatment.

Prospective Clinical and Biomarker Validation of the American Society for Transplantation and Cellular Therapy Consensus Definition for Transplantation-Associated Thrombotic Microangiopathy.

Transplantation-associated thrombotic microangiography (TA-TMA) is a disorder that causes severe complications after allogeneic hematopoietic cell transplantation (allo-HCT). Diagnosing TA-TMA is challenging because of the lack of standardized criteria. In this study, we aimed to evaluate the new TA-TMA consensus definition from the American Society for Transplantation and Cellular Therapy (ASTCT) panel as part of an ongoing prospective pediatric cohort study, and also to compare the impact and outcomes of using the current definition of clinical TMA (cTMA) versus the new consensus definition.

Pulmonary Histopathologic Findings in Pediatric Patients After Hematopoietic Stem Cell Transplantation: An Autopsy Study.

Background: Pathologic characterization of pulmonary complications following hematopoietic stem cell transplantation (HSCT) is limited. We describe lung findings in pediatric patients who died following HSCT and attempt to identify potential clinical associations.

Methods: Pathology databases at Texas Children's Hospital and the Children's Hospital of Philadelphia were queried (2013-2018 CHOP and 2017-2018 TCH).

Pathway-driven rare germline variants associated with transplant-associated thrombotic microangiopathy (TA-TMA).

The significance of rare germline mutations in transplant-associated thrombotic microangiopathy (TA-TMA) is not well studied. We performed a genetic association study in 100 adult TA-TMA patients vs. 98 post-transplant controls after matching by race, sex, and year.

Adolescent acquired thrombotic thrombocytopenic purpura: An analysis of the Pediatric Health Information System database.

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.

Haemolytic uraemic syndrome.

Haemolytic uraemic syndrome (HUS) is a heterogeneous group of diseases that result in a common pathology, thrombotic microangiopathy, which is classically characterised by the triad of non-immune microangiopathic haemolytic anaemia, thrombocytopenia, and acute kidney injury. In this Seminar, different causes of HUS are discussed, the most common being Shiga toxin-producing Escherichia coli HUS. Identifying the underlying thrombotic microangiopathy trigger can be challenging but is imperative if patients are to receive personalised disease-specific treatment.

Thrombosis and thromboembolism: Brighton collaboration case definition and guidelines for data collection, analysis, and presentation of immunization safety data.

This is a Brighton Collaboration case definition of thrombosis and thromboembolism to be used in the evaluation of adverse events following immunization, and for epidemiologic studies for the assessment of background incidence or hypothesis testing. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of SARS-CoV-2 vaccines. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation.

Practical considerations and consensus opinion for children's hospital-based inpatient hemostasis and thrombosis (HAT) consultative services: Communication from the ISTH SSC Subcommittee on Pediatric/Neonatal Thrombosis and Hemostasis.

Caring for children and adolescents with disorders of hemostasis and thrombosis (HAT) has become more specialized and requires a unique skill set that many providers are not able to obtain in standard pediatric hematology/oncology/bone marrow transplant fellowship training programs. The influx of numerous therapeutic advances and increasing medical complexity has expanded the need for experienced HAT providers and subspecialty collaboration in the inpatient setting due to the nuances in the management of patients with HAT complications and concerns. While there are data highlighting the benefits of an inpatient hemostasis, thrombosis, and anticoagulation management service in adult hospitals, there are limited pediatric data supporting such programs.

Comparison of Laboratory and Hemodynamic Time Series Data Across Original, Alpha, and Delta Variants in Patients With Multisystem Inflammatory Syndrome in Children.

Objectives: To compare the clinical, laboratory, and hemodynamic parameters during hospitalization for patients with multisystem inflammatory syndrome in children (MIS-C), across the Original/Alpha and the Delta variants of severe acute respiratory syndrome coronavirus 2 infection.

Design: Retrospective cohort study.

Setting: Single-center quaternary children's hospital.

Pulmonary embolism in pediatric and adolescent patients with COVID-19 infection during the SARS-CoV-2 delta wave.

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.

COVID-19 vaccine (mRNA BNT162b2) and COVID-19 infection-induced thrombotic thrombocytopenic purpura in adolescents.

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.

Role of anticoagulation in the management of tumor thrombus: A 10-year single-center experience.

Background: Children with cancer diagnosis are overall at a higher risk of thrombosis. For a newly diagnosed blood clot, patients are commonly started on anticoagulants to prevent further extension and embolization of the clot. In the rare instance that a pediatric patient has a tumor thrombus, role of anticoagulation is less clear.

Clinical characteristics and outcomes of combined thrombolysis and anticoagulation for pediatric and young adult lower extremity and inferior vena cava thrombosis.

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.

Determination of Antimicrobial Prescribing Practices in an Integrated Health System Emergency Department.

Introduction: Antibiotic stewardship utilizes interprofessional collaborative practices, including professionals from medicine, pharmacy, nursing, social services, and clinical laboratory science, to identify potential problems proactively. A tertiary care integrated health system's Emergency Department (ED) aimed to identify antimicrobials prescribed to the outpatient community as part of a proactive antimicrobial stewardship project.

Methods: A pilot, prospective, snapshot of a tertiary community hospital's outpatient antimicrobial prescribing habits was conducted.

Microvascular thrombosis: experimental and clinical implications.

A significant amount of clinical and research interest in thrombosis is focused on large vessels (eg, stroke, myocardial infarction, deep venous thrombosis, etc.); however, thrombosis is often present in the microcirculation in a variety of significant human diseases, such as disseminated intravascular coagulation, thrombotic microangiopathy, sickle cell disease, and others. Further, microvascular thrombosis has recently been demonstrated in patients with COVID-19, and has been proposed to mediate the pathogenesis of organ injury in this disease.

The alternative complement pathway activation product Ba as a marker for transplant-associated thrombotic microangiopathy.

Background: Transplant-associated thrombotic microangiopathy (TA-TMA) occurs after hematopoietic stem cell transplantation (HSCT) and is characterized by microvascular thrombosis and end-organ injury particularly of the kidneys. TA-TMA is challenging to diagnose and treat, which can lead to long-term complications and death in patients with severe disease. Studies have shown that genetic abnormalities of the alternative complement pathway (AP) are associated with TA-TMA.

In Utero Aortic Arch Thrombosis Masquerading as Interrupted Aortic Arch: A Case Report and Review of the Literature.

Aortic arch thrombosis is an extremely rare but life-threatening diagnosis that is often misdiagnosed in the neonatal period. Strategies including surgical intervention, systemic anticoagulation, and thrombolysis have been previously described in the treatment of these neonates. We describe the case of a neonate who presented with concern for interrupted aortic arch and was diagnosed with an in utero aortic arch thrombosis.

Therapeutic Plasma Exchange does not Improve Renal Function in Hematopoietic Stem Cell Transplantation-Associated Thrombotic Microangiopathy: An Institutional Experience.

Transplantation-associated thrombotic microangiopathy (TA-TMA) is a complication of hematopoietic stem cell transplant (HSCT) that causes severe multiorgan injury. The kidneys are almost universally affected. There is no proven therapy, but therapeutic plasma exchange (TPE) is commonly used to treat TA-TMA at Texas Children's Hospital (TCH).