Publications by authors named "Christopher Dvorak"

Introduction: While clinical practice guidelines (CPGs) for pediatric oncology infection prophylaxis and management exist, few data describe actual management occurring at pediatric oncology centers.

Methods: An electronic survey querying infection management practices in nontransplant pediatric oncology patients was iteratively created by the Children's Oncology Group (COG) Cancer Control and Supportive Care Infectious Diseases Subcommittee and sent to leaders at all COG institutions, limiting each site to one response to represent their institution.

Results: The response rate was 57% (129/227 institutions).

View Article and Find Full Text PDF
Article Synopsis
  • - C1q deficiency is a rare immune disorder that increases the risk of infections and autoimmune diseases similar to systemic lupus erythematosus (SLE), often leading to various health complications.
  • - An international study involving 18 patients evaluated the outcomes of hematopoietic stem cell transplantation (HSCT) for C1q deficiency, showing a 71% overall survival rate and improvement in autoimmune symptoms for most patients.
  • - The study highlights that patients with severe autoimmune symptoms have poorer survival rates, and specific antibodies were linked to different organ involvements, emphasizing the need for careful patient selection and risk assessment for HSCT as a treatment option.
View Article and Find Full Text PDF
Article Synopsis
  • Diffuse alveolar hemorrhage (DAH) is a serious lung complication that can occur after hematopoietic cell transplantation (HCT) in patients under 21, with a low incidence rate of about 1% in this population.
  • A study analyzed data from nearly 7,000 patients to identify risk factors for developing DAH, finding that nonmalignant hematologic disease, specific transplant medication regimens, and severe acute graft-versus-host disease significantly increased the risk.
  • Critical care patients with DAH also showed higher instances of various health issues, including systemic and pulmonary hypertension, and other serious conditions like renal failure.
View Article and Find Full Text PDF
Article Synopsis
  • * Researchers analyzed 562 patients across four IEI subgroups (combined immunodeficiency, severe combined immunodeficiency, neutrophil disorders, and hemophagocytic lymphohistiocytosis-related disorders), focusing on event-free survival (EFS) as the main outcome.
  • * The study concluded that targeting a cumulative busulfan exposure (AUCNONMEM) of around 80 mg × h/L can improve EFS and donor chimer
View Article and Find Full Text PDF

We hypothesized that the inferior disease-free survival (DFS) seen in older patients who underwent αβ-T-cell/CD19-depleted (AB-TCD) haploidentical hematopoietic cell transplantation (HCT) for hematologic malignancies is caused by excessive exposure to rabbit antithymocyte globulin (rATG; Thymoglobulin). Between 2015 and 2023, 163 patients with a median age of 13 years (range, 0.4-27.

View Article and Find Full Text PDF

Transplant associated thrombotic microangiopathy (TA-TMA) is a complication of hematopoietic cell transplant (HCT) associated with endothelial injury resulting in severe end organ damage, acute and long-term morbidity, and mortality. Myeloablative conditioning is a known risk factor, though specific causative agents have not been identified. We hypothesized that the combination of cyclophosphamide and thiotepa (CY + TT) is particularly toxic to the endothelium, placing patients at elevated risk for TA-TMA.

View Article and Find Full Text PDF
Article Synopsis
  • A study examined the incidence, risk factors, and outcomes of pulmonary hypertension (PH) in pediatric patients after hematopoietic stem cell transplants (HCT) conducted in a PICU setting from 2008 to 2014.
  • Out of nearly 7,000 HCT patients, 29 developed PH, revealing a low overall incidence of 0.42%, but a higher prevalence of 2.72% among patients needing intensive care post-transplant.
  • Key risk factors for developing PH included being Black/African American, having metabolic disorders, and a lower functional status prior to transplant, with patients experiencing significant complications and a 6-month survival rate of only 51.7% after PH diagnosis.
View Article and Find Full Text PDF

Hematopoietic cell transplantation (HCT) uses cytotoxic chemotherapy and/or radiation followed by intravenous infusion of stem cells to cure malignancies, bone marrow failure and inborn errors of immunity, hemoglobin and metabolism. Lung injury is a known complication of the process, due in part to disruption in the pulmonary microenvironment by insults such as infection, alloreactive inflammation and cellular toxicity. How microorganisms, immunity and the respiratory epithelium interact to contribute to lung injury is uncertain, limiting the development of prevention and treatment strategies.

View Article and Find Full Text PDF

Viral infections remain a major risk in immunocompromised pediatric patients, and virus-specific T cell (VST) therapy has been successful for treatment of refractory viral infections in prior studies. We performed a phase II multicenter study (NCT03475212) for the treatment of pediatric patients with inborn errors of immunity and/or post allogeneic hematopoietic stem cell transplant with refractory viral infections using partially-HLA matched VSTs targeting cytomegalovirus, Epstein-Barr virus, or adenovirus. Primary endpoints were feasibility, safety, and clinical responses (>1 log reduction in viremia at 28 days).

View Article and Find Full Text PDF

Sinusoidal obstructive syndrome (SOS), or veno-occlusive disease, of the liver has been recognized as a complex, life-threatening complication in the posthematopoietic stem cell transplant (HSCT) setting. The diagnostic criteria for SOS have evolved over the last several decades with a greater understanding of the underlying pathophysiology, with 2 recent diagnostic criteria introduced in 2018 (European Society of Bone Marrow Transplant [EBMT] criteria) and 2020 (Cairo criteria). We sought out to evaluate the performance characteristics in diagnosing and grading SOS in pediatric patients of the 4 different diagnostic criteria (Baltimore, Modified Seattle, EBMT, and Cairo) and severity grading systems (defined by the EBMT and Cairo criteria).

View Article and Find Full Text PDF

Severe combined immunodeficiency (SCID) is characterized by a severe deficiency in T cell numbers. We analyzed data collected (n = 307) for PHA-based T cell proliferation from the PIDTC SCID protocol 6901, using either a radioactive or flow cytometry method. In comparing the two groups, a smaller number of the patients tested by flow cytometry had <10% of the lower limit of normal proliferation as compared to the radioactive method (p = 0.

View Article and Find Full Text PDF

Background: P47phox (neutrophil cytosolic factor-1) deficiency is the most common cause of autosomal recessive chronic granulomatous disease (CGD) and is considered to be associated with a milder clinical phenotype. Allogeneic hematopoietic cell transplantation (HCT) for p47phox CGD is not well-described.

Objectives: We sought to study HCT for p47phox CGD in North America.

View Article and Find Full Text PDF
Article Synopsis
  • Allogeneic hematopoietic cell transplantation (HCT) in pediatric patients can lead to serious complications, requiring intensive care for a notable percentage of patients post-transplant.
  • A study analyzing data from multiple centers found that about 15.3% of patients needed ICU care within 5 years, with factors like patient demographics and pre-existing conditions influencing this need.
  • Although survival to discharge from the ICU is high (85.7%), many patients face ongoing health issues, resulting in a significant drop in long-term survival rates, especially among those with malignancies and poor organ function.
View Article and Find Full Text PDF
Article Synopsis
  • Lung injury is really important for kids' survival after getting special treatments for blood diseases, and scientists want to learn more about how germs and the body work together in the lungs.
  • In a big study, researchers looked at lung samples from 229 kids at 32 hospitals over 8 years and found 4 different groups of patients based on their lung microbe makeup.
  • Each group had different health outcomes: one group had low infection rates and low death rates, while others had high infection and death rates, showing that the type of lung microbes can greatly affect survival.
View Article and Find Full Text PDF

Background: The Primary Immune Deficiency Treatment Consortium (PIDTC) enrolled children in the United States and Canada onto a retrospective multicenter natural history study of hematopoietic cell transplantation (HCT).

Objective: We investigated outcomes of HCT for severe combined immunodeficiency (SCID).

Methods: We evaluated the chronic and late effects (CLE) after HCT for SCID in 399 patients transplanted from 1982 to 2012 at 32 PIDTC centers.

View Article and Find Full Text PDF

Background: Chronic granulomatous disease (CGD) is caused by defects in any 1 of the 6 subunits forming the nicotinamide adenine dinucleotide phosphate oxidase complex 2 (NOX2), leading to severely reduced or absent phagocyte-derived reactive oxygen species production. Almost 50% of patients with CGD have inflammatory bowel disease (CGD-IBD). While conventional IBD therapies can treat CGD-IBD, their benefits must be weighed against the risk of infection.

View Article and Find Full Text PDF
Article Synopsis
  • Allogeneic hematopoietic cell transplantation (HCT) can lead to complications requiring intensive care, but the risk factors for these complications are not well understood due to differences among treatment centers.
  • The study analyzed data from 6,995 pediatric HCT patients and found that 1,067 of them needed intensive care, with higher admission rates linked to factors like younger age, lower income, and certain pre-existing health conditions.
  • Among those who were admitted to intensive care, the survival rate to discharge was 85.7%, but many experienced readmissions, and overall long-term survival rates were significantly worse for patients with certain risk factors, particularly those with malignant diseases or existing organ dysfunction.*
View Article and Find Full Text PDF
Article Synopsis
  • Chronic granulomatous disease (CGD) is a serious immunodeficiency often treated with hematopoietic cell transplantation (HCT), which has shown a 3-year overall survival rate of 82% in patients studied.
  • Pre-existing inflammatory conditions and infections before HCT did not significantly impact survival, but a lower performance score and HLA mismatches were detrimental to outcomes.
  • Post-transplant, patients experienced significant health improvements, with reduced disease burden and lower medication use compared to non-transplant patients, indicating HCT is a robust treatment option for CGD.
View Article and Find Full Text PDF

Diffuse alveolar hemorrhage (DAH) is a life-threatening complication of hematopoietic cellular therapy (HCT). This study aimed to evaluate the effect of DAH treatments on outcomes using data from consecutive HCT patients clinically diagnosed with DAH from 3 institutions between January 2018-August 2022. Endpoints included sustained complete response (sCR) defined as bleeding cessation without recurrent bleeding, and non-relapse mortality (NRM).

View Article and Find Full Text PDF

The objective of the Cancer Control and Supportive Care (CCL) Committee in the Children's Oncology Group (COG) is to reduce the overall morbidity and mortality of therapy-related toxicities in children, adolescents, and young adults with cancer. We have targeted five major domains that cause clinically important toxicity: (i) infections and inflammation; (ii) malnutrition and metabolic dysfunction; (iii) chemotherapy-induced nausea and vomiting; (iv) neuro- and oto-toxicty; and (v) patient-reported outcomes and health-related quality of life. Subcommittees for each domain prioritize randomized controlled trials and biology aims to determine which strategies best mitigate the toxicities.

View Article and Find Full Text PDF

Background: Severe combined immunodeficiency (SCID) is fatal unless durable adaptive immunity is established, most commonly through allogeneic haematopoietic cell transplantation (HCT). The Primary Immune Deficiency Treatment Consortium (PIDTC) explored factors affecting the survival of individuals with SCID over almost four decades, focusing on the effects of population-based newborn screening for SCID that was initiated in 2008 and expanded during 2010-18.

Methods: We analysed transplantation-related data from children with SCID treated at 34 PIDTC sites in the USA and Canada, using the calendar time intervals 1982-89, 1990-99, 2000-09, and 2010-18.

View Article and Find Full Text PDF

Consolidation with autologous hematopoietic stem cell transplantation (HSCT) has improved survival for patients with central nervous system tumors (CNSTs). The impact of the autologous graft CD34+ dose on patient outcomes is unknown. We wanted to analyze the relationship between CD34 dose, total nucleated cell (TNC) dose, and clinical outcomes, including overall survival (OS), progression-free survival (PFS), relapse, non-relapse mortality (NRM), endothelial-injury complications (EIC), and time to neutrophil engraftment in children undergoing autologous HSCT for CNSTs.

View Article and Find Full Text PDF