92 research outputs found

    Robust Estimators in Generalized Pareto Models

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    This paper deals with optimally-robust parameter estimation in generalized Pareto distributions (GPDs). These arise naturally in many situations where one is interested in the behavior of extreme events as motivated by the Pickands-Balkema-de Haan extreme value theorem (PBHT). The application we have in mind is calculation of the regulatory capital required by Basel II for a bank to cover operational risk. In this context the tail behavior of the underlying distribution is crucial. This is where extreme value theory enters, suggesting to estimate these high quantiles parameterically using, e.g. GPDs. Robust statistics in this context offers procedures bounding the influence of single observations, so provides reliable inference in the presence of moderate deviations from the distributional model assumptions, respectively from the mechanisms underlying the PBHT.Comment: 26pages, 6 figure

    Donor Killer Immunoglobulin Receptor Gene Content and Ligand Matching and Outcomes of Pediatric Patients with Juvenile Myelomonocytic Leukemia Following Unrelated Donor Transplantation

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    Natural killer (NK) cell determinants predict relapse-free survival after allogeneic hematopoietic cell transplantation (HCT) for acute myelogenous leukemia, and previous studies have shown a beneficial graft-versus-leukemia effect in patients with juvenile myelomonocytic leukemia (JMML). However, whether NK cell determinants predict protection against relapse for JMML patients undergoing HCT is unknown. Therefore, we investigated NK cell-related donor and recipient immunogenetics as determinants of HCT outcomes in patients with JMML. Patients with JMML (age 0 to 3 (HR, 0.52; 95% CI, 0.29 to 0.95; P = .032), centromeric A/B score (HR, 0.57; 95% CI, 033 to 0.98; P = .041), and telomeric A/B score (HR, 0.58; 95% CI, 0.34 to 1.00; P = .048). To our knowledge, this is the first study analyzing the association of NK cell determinants and outcomes in JMML HCT recipients. This study identifies potential benefits of donor KIR-B genotypes in reducing aGVHD. Our findings warrant further study of the role of NK cells in enhancing the graft-versus-leukemia effect via recognition of JMML blasts

    Late Effects in Hematopoietic Cell Transplant Recipients with Acquired Severe Aplastic Anemia: A Report from the Late Effects Working Committee of the Center for International Blood and Marrow Transplant Research

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    With improvements in hematopoietic cell transplant (HCT) outcomes for severe aplastic anemia (SAA), there is a growing population of SAA survivors after HCT. However, there is a paucity of information regarding late effects that occur after HCT in SAA survivors. This study describes the malignant and nonmalignant late effects in survivors with SAA after HCT. A descriptive analysis was conducted of 1718 patients post-HCT for acquired SAA between 1995 and 2006 reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). the prevalence and cumulative incidence estimates of late effects are reported for 1-year HCT survivors with SAA. of the HCT recipients, 1176 (68.5%) and 542 (31.5%) patients underwent a matched sibling donor (MSD) or unrelated donor (URD) HCT, respectively. the median age at the time of HCT was 20 years. the median interval from diagnosis to transplantation was 3 months for MSD HCT and 14 months for URD HCT. the median follow-up was 70 months and 67 months for MSD and URD HCT survivors, respectively. Overall survival at I year, 2 years, and 5 years for the entire cohort was 76% (95% confidence interval [CI]: 74-78), 73% (95% CI: 71-75), and 70% (95% CI: 68-72). Among 1-year survivors of MSD HCT, 6% had 1 late effect and 1% had multiple late effects. for 1-year survivors of URD HCT, 13% had 1 late effect and 2% had multiple late effects. Among survivors of MSD HCT, the cumulative incidence estimates of developing late effects were all <3% and did not increase over time. in contrast, for recipients of URD HCT, the cumulative incidence of developing several late effects exceeded 3% by 5 years: gonadal dysfunction 10.5% (95% CI: 7.3-14.3), growth disturbance 7.2% (95% CI: 4.4-10.7), avascular necrosis 6.3% (95% CI: 3.6-9.7), hypothyroidism 5.5% (95% CI: 2.8-9.0), and cataracts 5.1% (95% CI: 2.9-8.0). Our results indicated that all patients undergoing HCT for SAA remain at risk for late effects, must be counseled about, and should be monitored for late effects for the remainder of their lives.Public Health Service Grant from the National Cancer InstituteNational Heart, Lung, and Blood InstituteNational Institute of Allergy and Infectious DiseasesNational Cancer InstituteHealth Resources and Services Administration/Department of Health and Human ServicesOffice of Naval ResearchAllosAmgenAngioblastChildrens Hosp Orange Cty, Dept Hematol, Orange, CA 92668 USACIBMTR Med Coll Wisconsin, Dept Biostat, Milwaukee, WI USAMed Coll Wisconsin, CIBMTR Stat Ctr, Milwaukee, WI 53226 USAKing Faisal Specialist Hosp & Res Ctr, Dept Oncol, Riyadh 11211, Saudi ArabiaNew York Med Coll, Dept Pediat Hematol Oncol & Stem Cell Transplanta, Valhalla, NY 10595 USAStemcyte, Covina, CA USADana Farber Canc Inst, Dept Pediat Oncol, Boston, MA 02115 USAUniv Florida, Dept Hematol Oncol, Gainesville, FL USAPrincess Margaret Hosp, Dept Med, Toronto, ON M4X 1K9, CanadaUniv S Florida, All Childrens Hosp, Dept Pediat Hematol & Oncol, St Petersburg, FL 33701 USAUniv Basel Hosp, Dept Hematol, CH-4031 Basel, SwitzerlandOregon Hlth & Sci Univ, Dept Hematol & Oncol, Portland, OR 97201 USAChildrens Natl Med Ctr, Dept Blood & Marrow Transplantat, Washington, DC 20010 USABaylor Coll Med, Ctr Cell Therapy, Dept Hematol & Oncol, Houston, TX 77030 USAUniv N Carolina Hosp, Dept Pediat, Chapel Hill, NC USAUniv Hosp Case, Med Ctr, Dept Med, Cleveland, OH USAUniv Arkansas Med Sci, Dept Hematol & Oncol, Little Rock, AR 72205 USACincinnati Childrens Hosp Med Ctr, Dept Bone Marrow Transplantat & Immune Deficiency, Cincinnati, OH USATufts Med Ctr, Dept Med & Pediat, Boston, MA USAUniv S Florida, Coll Med, H Lee Moffitt Canc Ctr & Res Inst, Dept Hematol & Oncol, Tampa, FL 33612 USAFlorida Ctr Cellular Therapy, Dept Med, Orlando, FL USAUniv Fed Parana, Dept Bone Marrow Transplantat, BR-80060000 Curitiba, Parana, BrazilVanderbilt Univ, Med Ctr, Dept Med, Nashville, TN USAInst Oncol Pediat, Dept Pediat, SĂŁo Paulo, BrazilFred Hutchinson Canc Res Ctr, Dept Clin Res & Transplantat, Seattle, WA 98104 USAMt Sinai Med Ctr, Dept Bone Marrow & Stem Cell Transplantat, New York, NY 10029 USAUniv N Carolina Hosp, Dept Hematol & Oncol, Chapel Hill, NC USAUniv Manitoba, CancerCare Manitoba, Dept Manitoba Blood & Marrow Transplant Program, Winnipeg, MB, CanadaKarolinska Univ Hosp, Ctr Allogene Stem Cell Transplantat, Dept Pediat, Stockholm, SwedenLouisiana State Univ, Hlth Sci Ctr, Childrens Hosp, Dept Pediat, New Orleans, LA USADept Natl Marrow Donor Program, Minneapolis, MN USAPublic Health Service Grant from the National Cancer Institute: U24-CA76518National Heart, Lung, and Blood Institute: 5U01HL069294Office of Naval Research: N00014-06-1-0704Office of Naval Research: N00014-08-1-0058HHSH234200637015CWeb of Scienc

    Late effects in hematopoietic cell transplant recipients with acquired severe aplastic anemia: a report from the late effects working committee of the center for international blood and marrow transplant research (CIBMTR)

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    CHOC Children’s Hospital - UC Irvine, Orange, CAMedical College of Wisconsin, Milwaukee, WIMedical College of Wisconsin, Milwaukee, WIKing Faisal Specialist Hospital and Research Center, Riyadh, TX, Saudi ArabiaNew York Medical College, Valhalla, NYStemcyte, Covina, CADana Farber Cancer Institute, Boston, MAUniversity of Florida, Gainesville, FLPrincess Margaret Hospital, Toronto, ON, CanadaAll Children’s Hospital, St. Petersburg, FLUniversity Hospital Basel, Basel, SwitzerlandOregon Health and Science University, Portland, ORChildren’s National Medical Center, Washington, DCBaylor College of Medicine Center for Cell Therapy, Houston, TXUniversity of North Carolina Hospitals, Chapel Hill, NCUniversity Hospitals Case Medical Center, Cleveland, OHUniversity of Arkansas for Medical Sciences, Little Rock, ARCincinnati Children’s Hospital Medical Center, Cincinnati, OHTufts Medical Center, Boston, MAH Lee Moffitt Cancer Center and Research Institute, Tampa, FLFlorida Center for Cellular Therapy, Orlando, FLUniversidade Federal de Parana, Curitiba, BrazilVanderbilt University Medical Center, Nashville, TNInstituto de Oncologia Pediatrica, Sao Paulo, BrazilFred Hutchinson Cancer Research Center, Seattle, WAMount Sinai Medical Center, New York, NYUniversity of North Carolina, Chapel Hill, NCCancerCare Manitoba, University of Manitoba, Winnipeg, CanadaKarolinska University Hospital, Center for Allogeneic Stem Cell Transplantation, Stockholm, SwedenChildrens Hospital LSU Health Sciences Center, New Orleans, LANational Marrow Donor Program, Minneapolis, MNWeb of Scienc

    Pulmonary hypertension in the intensive care unit after pediatric allogeneic hematopoietic stem cell transplant: incidence, risk factors, and outcomes

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    ObjectiveTo determine the incidence, risk factors, and outcomes of pulmonary hypertension (PH) in the pediatric intensive care unit (PICU) after pediatric hematopoietic stem cell transplant (HCT).MethodsThis was a retrospective study of pediatric patients who underwent allogeneic HCT between January 2008-December 2014 at a center contributing to the Center for International Blood and Marrow Transplant Research data registry. Incidence of PH was assessed from PICU diagnostic codes from records merged from the Virtual Pediatric Systems database. Regression and survival analyses identified factors associated with post-HCT PH. Additional post-HCT morbidities and survival after PH were also assessed.ResultsAmong 6,995 HCT recipients, there were 29 cases of PH, a cumulative incidence of 0.42% (95% CI 0.27%-0.57%) at 60 months post-HCT. In the sub-cohort of 1,067 patients requiring intensive care after HCT, this accounted for a PH prevalence of 2.72% (95% CI 1.74–3.69%). There was an increased risk of developing PH associated with Black/African American race, metabolic disorders, partially HLA-matched or cord blood allografts, graft-versus-host prophylaxis regimen, and lower pre-HCT functional status. Patients who developed PH had significant PICU comorbidities including heart failure, pulmonary hemorrhage, respiratory failure, renal failure, and infections. Survival at 6 months after diagnosis of post-HCT PH was 51.7% (95% CI 32.5%-67.9%).ConclusionsPH is a rare but serious complication in the pediatric post-HCT population. A significant burden of additional comorbidities, procedural interventions, and risk of mortality is associated with its development. Close monitoring and prompt intervention for this severe complication are necessary in this vulnerable population

    Comparison of Characteristics and Outcomes of Trial Participants and Nonparticipants: Example of Blood and Marrow Transplant Clinical Trials Network 0201 Trial

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    Controversy surrounds the question of whether clinical trial participants have better outcomes than comparable patients who are not treated on a trial. We explored this question using a recent large, randomized, multi-center study comparing peripheral blood (PB) with bone marrow (BM) transplantation from unrelated donors (URD), conducted by the Blood and Marrow Transplant Clinical Trials Network (BMT CTN)
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