Publications by authors named "Allyson Flower"

10 Publications

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Immune profile differences between chronic GVHD and late acute GVHD: results of the ABLE/PBMTC 1202 studies.

Blood 2020 04;135(15):1287-1298

CancerCare Manitoba, University of Manitoba, Winnipeg, MB, Canada.

Human graft-versus-host disease (GVHD) biology beyond 3 months after hematopoietic stem cell transplantation (HSCT) is complex. The Applied Biomarker in Late Effects of Childhood Cancer study (ABLE/PBMTC1202, NCT02067832) evaluated the immune profiles in chronic GVHD (cGVHD) and late acute GVHD (L-aGVHD). Peripheral blood immune cell and plasma markers were analyzed at day 100 post-HSCT and correlated with GVHD diagnosed according to the National Institutes of Health consensus criteria (NIH-CC) for cGVHD. Of 302 children enrolled, 241 were evaluable as L-aGVHD, cGVHD, active L-aGVHD or cGVHD, and no cGVHD/L-aGVHD. Significant marker differences, adjusted for major clinical factors, were defined as meeting all 3 criteria: receiver-operating characteristic area under the curve ≥0.60, P ≤ .05, and effect ratio ≥1.3 or ≤0.75. Patients with only distinctive features but determined as cGVHD by the adjudication committee (non-NIH-CC) had immune profiles similar to NIH-CC. Both cGVHD and L-aGVHD had decreased transitional B cells and increased cytolytic natural killer (NK) cells. cGVHD had additional abnormalities, with increased activated T cells, naive helper T (Th) and cytotoxic T cells, loss of CD56bright regulatory NK cells, and increased ST2 and soluble CD13. Active L-aGVHD before day 114 had additional abnormalities in naive Th, naive regulatory T (Treg) cell populations, and cytokines, and active cGVHD had an increase in PD-1- and a decrease in PD-1+ memory Treg cells. Unsupervised analysis appeared to show a progression of immune abnormalities from no cGVHD/L-aGVHD to L-aGVHD, with the most complex pattern in cGVHD. Comprehensive immune profiling will allow us to better understand how to minimize L-aGVHD and cGVHD. Further confirmation in adult and pediatric cohorts is needed.
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http://dx.doi.org/10.1182/blood.2019003186DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7146024PMC
April 2020

Benefits and challenges with diagnosing chronic and late acute GVHD in children using the NIH consensus criteria.

Blood 2019 07 1;134(3):304-316. Epub 2019 May 1.

British Columbia Children's Hospital, University of British Columbia, Vancouver, BC, Canada.

Chronic graft-versus-host disease (cGVHD) and late acute graft-versus-host disease (L-aGVHD) are understudied complications of allogeneic hematopoietic stem cell transplantation in children. The National Institutes of Health Consensus Criteria (NIH-CC) were designed to improve the diagnostic accuracy of cGVHD and to better classify graft-versus-host disease (GVHD) syndromes but have not been validated in patients <18 years of age. The objectives of this prospective multi-institution study were to determine: (1) whether the NIH-CC could be used to diagnose pediatric cGVHD and whether the criteria operationalize well in a multi-institution study; (2) the frequency of cGVHD and L-aGVHD in children using the NIH-CC; and (3) the clinical features and risk factors for cGVHD and L-aGVHD using the NIH-CC. Twenty-seven transplant centers enrolled 302 patients <18 years of age before conditioning and prospectively followed them for 1 year posttransplant for development of cGVHD. Centers justified their cGVHD diagnosis according to the NIH-CC using central review and a study adjudication committee. A total of 28.2% of reported cGVHD cases was reclassified, usually as L-aGVHD, following study committee review. Similar incidence of cGVHD and L-aGVHD was found (21% and 24.7%, respectively). The most common organs involved with diagnostic or distinctive manifestations of cGVHD in children include the mouth, skin, eyes, and lungs. Importantly, the 2014 NIH-CC for bronchiolitis obliterans syndrome perform poorly in children. Past acute GVHD and peripheral blood grafts are major risk factors for cGVHD and L-aGVHD, with recipients ≥12 years of age being at risk for cGVHD. Applying the NIH-CC in pediatrics is feasible and reliable; however, further refinement of the criteria specifically for children is needed.
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http://dx.doi.org/10.1182/blood.2019000216DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6911839PMC
July 2019

An unusual case of hemophagocytic lymphohistiocytosis diagnosed by spinal nerve root biopsy.

J Neurosurg Pediatr 2019 04 5:1-5. Epub 2019 Apr 5.

Department of Neurosurgery; and

Hemophagocytic lymphohistiocytosis (HLH) is a rare disease process characterized by aberrant immune system activation and an exaggerated inflammatory response. Establishing the diagnosis may be challenging and is achieved by satisfying a number of clinical criteria, in addition to demonstrating tissue hemophagocytosis. This syndrome is rapidly fatal if prompt diagnosis and treatment are not achieved. The authors present the case of a 17-year-old male patient with CNS HLH involving both the brain and spinal cord, highlighting the variable CNS manifestations in pediatric patients with HLH and the challenges that accompany establishing diagnosis.
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http://dx.doi.org/10.3171/2019.1.PEDS18591DOI Listing
April 2019

An Argument for Adolescent and Young Adult Cancer Registry: One Model.

J Adolesc Young Adult Oncol 2019 06 1;8(3):379-384. Epub 2019 Feb 1.

1 Department of Pediatrics, New York Medical College, Valhalla, New York.

Over the last several years, there has been increasing awareness around the unique challenges faced by adolescent and young adult (AYA) cancer patients. More cancer centers across the United States are introducing AYA-specific programs to help improve outcomes for these patients. However, given the nature of the United States health care system, there is little ability to track the efficacy of these programs and identify important variables with respect to both interdisciplinary interventions offered and medical and psychosocial outcomes. One program offers an argument as to why tracking these data is important, with a description of the registry they have developed.
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http://dx.doi.org/10.1089/jayao.2018.0122DOI Listing
June 2019

Mature (non-anaplastic, non-cutaneous) T-/NK-cell lymphomas in children, adolescents and young adults: state of the science.

Br J Haematol 2019 05 1;185(3):418-435. Epub 2019 Feb 1.

Department of Pediatrics, New York Medical College, Valhalla, NY, USA.

Mature (non-anaplastic) T-cell and natural killer (NK)-lymphomas rarely occur in children or adolescents. Due to the low incidence and heterogeneity, information regarding the aetiology, physiopathology and genetics of paediatric mature (non-anaplastic) T/NK-cell lymphoma is lacking. In addition, standard treatments have not yet been established. In the absence of randomised clinical trials, anthracycline-containing regimens are usually considered as the first treatment option, but with discouraging outcomes, especially in patients with advanced disease. The implementation of autologous or allogeneic stem cell transplantation as upfront consolidation therapy or for chemotherapy-sensitive relapsed disease have resulted in improved survival for some patient subsets. The recent use of novel targeted molecular and immunotherapeutic agents has also been shown to be promising in small numbers of patients. In this context, we will review the current state of the scientific knowledge on the most common mature (non-anaplastic, non-cutaneous) T/NK-cell lymphomas occurring in children, adolescent and young adults.
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http://dx.doi.org/10.1111/bjh.15767DOI Listing
May 2019

NHL in adolescents and young adults: A unique population.

Pediatr Blood Cancer 2018 08 9;65(8):e27073. Epub 2018 May 9.

Department of Pediatrics, New York Medical College, Valhalla, New York.

Non-Hodgkin lymphoma (NHL) is a heterogeneous group of lymphoid malignancies with high incidence in adolescents and young adults (AYAs). The most common diseases include diffuse large B-cell lymphoma, anaplastic large cell lymphoma, Burkitt lymphoma, lymphoblastic lymphoma, and primary mediastinal large B-cell lymphoma. In comparison to younger children and adults, AYAs (15-39 years) with NHL present a specific set of challenges including variations in tumor biology, inconsistent treatment, pharmacodynamics, and psychosocial barriers. While survival of AYAs with NHL has improved, cure rates remain suboptimal. Incorporation of novel agents into pediatric-inspired treatment regimens specifically designed for NHL in AYAs has led to improved outcomes. Consideration of AYAs as a distinct population in the diagnosis and treatment of NHL is encouraged.
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http://dx.doi.org/10.1002/pbc.27073DOI Listing
August 2018

Levocarnitine for asparaginase-induced hepatic injury: a multi-institutional case series and review of the literature.

Leuk Lymphoma 2018 10 12;59(10):2360-2368. Epub 2018 Feb 12.

g Department of Radiation Medicine , Oregon Health and Science University , Portland , OR , USA.

Asparaginase, an important treatment component for acute lymphoblastic leukemia (ALL), causes severe hepatotoxicity in some patients. Levocarnitine is a mitochondrial co-factor that can potentially ameliorate the mitochondrial toxicity of asparaginase. In this retrospective case series, we describe the clinical presentation and management of six pediatric and young adult patients (mean age 12.7, range 9-24 years) with ALL who developed Grade 3-4 hyperbilirubinemia following administration of asparaginase as part of induction/re-induction therapy. Five of these patients were treated with levocarnitine with subsequent improvement of hyperbilirubinemia, while one patient was given levocarnitine prophylactically during induction and developed Grade 3 hyperbilirubinemia, but did not require therapy adjustments or delays. Increased awareness in the pediatric oncology community regarding asparaginase-associated hepatic toxicity and the potential role of levocarnitine in management is warranted.
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http://dx.doi.org/10.1080/10428194.2018.1435873DOI Listing
October 2018

The evolution of allogeneic stem cell transplant for children and adolescents with acute myeloid leukemia.

Clin Adv Hematol Oncol 2017 Jan;15(1):52-62

New York Medical College, Valhalla, New York.

Survival rates in subsets of pediatric patients who have acute myeloid leukemia (AML) with favorable risk features are now greater than 90%. However, outcomes for patients with high-risk (HR) features remain unacceptably poor. As novel technologies for the identification of HR biomarkers and the detection of residual disease are developed, risk stratification and the application of allogeneic hematopoietic stem cell transplant (HSCT) are evolving. HSCT has been shown to benefit subpopulations of pediatric patients with AML, including those with HR cytogenetic translocations, genetic mutations, and/or residual disease after induction. Targeted therapies have shown promise for improving outcomes, and their integration into standard therapy and HSCT regimens is a critical area of interest. Also, expansion of the donor pool has led to the successful use of alternative donor sources for those patients without a matched sibling. However, transplant-related morbidity and mortality and late effects are major limiting factors. Reduced-intensity conditioning regimens have resulted in outcomes equivalent to those achieved with myeloablative regimens among patients in complete remission. The limitation of transplant-related morbidity and mortality through reduced-intensity conditioning and supportive care, and improved survival through optimal alloreactivity in combination with targeted therapy, are steps toward advancing outcomes for pediatric patients who have AML with HR features.
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January 2017

Genetically re-engineered K562 cells significantly expand and functionally activate cord blood natural killer cells: Potential for adoptive cellular immunotherapy.

Exp Hematol 2017 Feb 17;46:38-47. Epub 2016 Oct 17.

Department of Pediatrics, New York Medical College, Valhalla, NY, USA; Department of Medicine, New York Medical College, Valhalla, NY, USA; Department of Pathology, New York Medical College, Valhalla, NY, USA; Department of Microbiology and Immunology, New York Medical College, Valhalla, NY, USA; Department of Cell Biology and Anatomy, New York Medical College, Valhalla, NY, USA. Electronic address:

Natural killer (NK) cells play a significant role in reducing relapse in patients with hematological malignancies after allogeneic stem cell transplantation, but NK cell number and naturally occurring inhibitory signals limit their capability. Interleukin-15 (IL-15) and 4-1BBL are important modulators of NK expansion and functional activation. To overcome these limitations, cord blood mononuclear cells (CB MNCs) were ex vivo expanded for 7 days with genetically modified K562-mbIL15-41BBL (MODK562) or wild-type K562 (WTK562). NK cell expansion; expression of lysosome-associated membrane protein-1 (LAMP-1), granzyme B, and perforin; and in vitro and in vivo cytotoxicity against B-cell non-Hodgkin lymphoma (B-NHL) were evaluated. In vivo tumor growth in B-NHL-xenografted nonobese diabetic severe combined immune deficient (NOD-scid) gamma (NSG) mice was monitored by tumor volume, cell number, and survival. CB MNCs cultured with MODK562 compared with WTK562 demonstrated significantly increased NK expansion (thirty-fivefold, p < 0.05); LAMP-1 (p < 0.05), granzyme B, and perforin expression (p < 0.001); and in vitro cytotoxicity against B-NHL (p < 0.01). Xenografted mice treated with MODK562 CB experienced significantly decreased B-NHL tumor volume (p = 0.0086) and B-NHL cell numbers (p < 0.01) at 5 weeks and significantly increased survival (p < 0.001) at 10 weeks compared with WTK562. In summary, MODK562 significantly enhanced CB NK expansion and cytotoxicity, enhanced survival in a human Burkitt's lymphoma xenograft NSG model, and could be used in the future as adoptive cellular immunotherapy after umbilical CB transplantation. Future directions include expanding anti-CD20 chimeric receptor-modified CB NK cells to enhance B-NHL targeting in vitro and in vivo.
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http://dx.doi.org/10.1016/j.exphem.2016.10.003DOI Listing
February 2017

Modification of Expanded NK Cells with Chimeric Antigen Receptor mRNA for Adoptive Cellular Therapy.

Methods Mol Biol 2016 ;1441:215-30

Department of Pediatrics, New York Medical College, Valhalla, NY, 10595, USA.

NK cells are bone marrow-derived cytotoxic lymphocytes that play a major role in the rejection of tumors and cells infected by viruses. The regulation of NK activation vs inhibition is regulated by the expression of a variety of NK receptors (NKRs) and specific NKRs' ligands expressed on their targets. However, factors limiting NK therapy include small numbers of active NK cells in unexpanded peripheral blood and lack of specific tumor targeting. Chimeric antigen receptors (CAR) usually include a single-chain Fv variable fragment from a monoclonal antibody, a transmembrane hinge region, and a signaling domain such as CD28, CD3-zeta, 4-1BB (CD137), or 2B4 (CD244) endodimers. Redirecting NK cells with a CAR will circumvent the limitations of the lack of NK targeting specificity. This chapter focuses on the methods to expand human NK cells from peripheral blood by co-culturing with feeder cells and to modify the expanded NK cells efficiently with the in vitro transcribed CAR mRNA by electroporation and to test the functionality of the CAR-modified expanded NK cells for use in adoptive cellular immunotherapy.
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http://dx.doi.org/10.1007/978-1-4939-3684-7_18DOI Listing
December 2017