115 research outputs found

    Pervasive gene content variation and copy number variation in maize and its undomesticated progenitor

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    Individuals of the same species are generally thought to have very similar genomes. However, there is growing evidence that structural variation in the form of copy number variation (CNV) and presence-absence variation (PAV) can lead to variation in the genome content of individuals within a species. Array comparative genomic hybridization (CGH) was used to compare gene content and copy number variation among 19 diverse maize inbreds and 14 genotypes of the wild ancestor of maize, teosinte. We identified 479 genes exhibiting higher copy number in some genotypes (UpCNV) and 3410 genes that have either fewer copies or are missing in the genome of at least one genotype relative to B73 (DownCNV/PAV). Many of these DownCNV/PAV are examples of genes present in B73, but missing from other genotypes. Over 70% of the CNV/PAV examples are identified in multiple genotypes, and the majority of events are observed in both maize and teosinte, suggesting that these variants predate domestication and that there is not strong selection acting against them. Many of the genes affected by CNV/PAV are either maize specific (thus possible annotation artifacts) or members of large gene families, suggesting that the gene loss can be tolerated through buffering by redundant functions encoded elsewhere in the genome. While this structural variation may not result in major qualitative variation due to genetic buffering, it may significantly contribute to quantitative variation

    Allogeneic Hematopoietic Cell Transplantation Provides Effective Salvage Despite Refractory Disease or Failed Prior Autologous Transplant in Angioimmunoblastic T-Cell Lymphoma: A CIBMTR Analysis

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    Background: There is a paucity of data on the role of allogeneic hematopoietic cell transplantation (allo-HCT) in patients with angioimmunoblastic T-cell lymphoma (AITL). Using the CIBMTR registry, we report here the outcomes of AITL patients undergoing an allo-HCT. Methods: We evaluated 249 adult AITL patients who received their first allo-HCT during 2000–2016. Results: The median patient age was 56 years (range = 21–77). Majority of the patients were Caucasians (86%), with a male predominance (60%). Graft-versus-host disease (GVHD) prophylaxis was predominantly calcineurin inhibitor-based approaches while the most common graft source was peripheral blood (97%). Median follow-up of survivors was 49 months (range = 4–170 months). The cumulative incidence of grade 2–4 and grade 3–4 acute GVHD at day 180 were 36% (95% CI = 30–42) and 12 (95% CI = 8–17), respectively. The cumulative incidence of chronic GVHD at 1 year was 49% (95%CI 43–56). The 1-year non-relapse mortality (NRM) was 19% (95% CI = 14–24), while the 4-year relapse/progression, progression-free survival (PFS), and overall survival (OS) were 21% (95% CI = 16–27), 49% (95% CI = 42–56), and 56% (95% CI = 49–63), respectively. On multivariate analysis, chemoresistant status at the time of allo-HCT was associated with a significantly higher risk for therapy failure (inverse of PFS) (RR = 1.73 95% CI = 1.08–2.77), while KPS \u3c 90% was associated with a significantly higher risk of mortality (inverse of OS) (RR = 3.46 95% CI = 1.75–6.87). Conclusion: Our analysis shows that allo-HCT provides durable disease control even in AITL patients who failed a prior auto-HCT and in those subjects with refractory disease at the time of allografting

    Allogeneic Transplantation Provides Durable Remission in a Subset of DLBCL Patients Relapsing after Autologous Transplantation

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    For diffuse large B-cell lymphoma (DLBCL) patients progressing after autologous haematopoietic cell transplantation (autoHCT), allogeneic HCT (alloHCT) is often considered, although limited information is available to guide patient selection. Using the Center for International Blood and Marrow Transplant Research (CIBMTR) database, we identified 503 patients who underwent alloHCT after disease progression/relapse following a prior autoHCT. The 3-year probabilities of non-relapse mortality, progression/relapse, progression-free survival (PFS) and overall survival (OS) were 30, 38, 31 and 37% respectively. Factors associated with inferior PFS on multivariate analysis included Karnofsky performance status (KPS) <80, chemoresistance, autoHCT to alloHCT interval <1-year and myeloablative conditioning. Factors associated with worse OS on multivariate analysis included KPS<80, chemoresistance and myeloablative conditioning. Three adverse prognostic factors were used to construct a prognostic model for PFS, including KPS<80 (4 points), autoHCT to alloHCT interval <1-year (2 points) and chemoresistant disease at alloHCT (5 points). This CIBMTR prognostic model classified patients into four groups: low-risk (0 points), intermediate-risk (2-5 points), high-risk (6-9 points) or very high-risk (11 points), predicting 3-year PFS of 40, 32, 11 and 6%, respectively, with 3-year OS probabilities of 43, 39, 19 and 11% respectively. In conclusion, the CIBMTR prognostic model identifies a subgroup of DLBCL patients experiencing long-term survival with alloHCT after a failed prior autoHCT

    Allogeneic hematopoietic cell transplantation provides effective salvage despite refractory disease or failed prior autologous transplant in angioimmunoblastic T-cell lymphoma: a CIBMTR analysis

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    Abstract Background There is a paucity of data on the role of allogeneic hematopoietic cell transplantation (allo-HCT) in patients with angioimmunoblastic T-cell lymphoma (AITL). Using the CIBMTR registry, we report here the outcomes of AITL patients undergoing an allo-HCT. Methods We evaluated 249 adult AITL patients who received their first allo-HCT during 2000–2016. Results The median patient age was 56 years (range = 21–77). Majority of the patients were Caucasians (86%), with a male predominance (60%). Graft-versus-host disease (GVHD) prophylaxis was predominantly calcineurin inhibitor-based approaches while the most common graft source was peripheral blood (97%). Median follow-up of survivors was 49 months (range = 4–170 months). The cumulative incidence of grade 2–4 and grade 3–4 acute GVHD at day 180 were 36% (95% CI = 30–42) and 12 (95% CI = 8–17), respectively. The cumulative incidence of chronic GVHD at 1 year was 49% (95%CI 43–56). The 1-year non-relapse mortality (NRM) was 19% (95% CI = 14–24), while the 4-year relapse/progression, progression-free survival (PFS), and overall survival (OS) were 21% (95% CI = 16–27), 49% (95% CI = 42–56), and 56% (95% CI = 49–63), respectively. On multivariate analysis, chemoresistant status at the time of allo-HCT was associated with a significantly higher risk for therapy failure (inverse of PFS) (RR = 1.73 95% CI = 1.08–2.77), while KPS < 90% was associated with a significantly higher risk of mortality (inverse of OS) (RR = 3.46 95% CI = 1.75–6.87). Conclusion Our analysis shows that allo-HCT provides durable disease control even in AITL patients who failed a prior auto-HCT and in those subjects with refractory disease at the time of allografting.https://deepblue.lib.umich.edu/bitstream/2027.42/146782/1/13045_2018_Article_696.pd

    Myeloablative vs Reduced-Intensity Conditioning Allogeneic Hematopoietic Cell Transplantation for Chronic Myeloid Leukemia

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    Allogeneic hematopoietic cell transplantation (allo-HCT) is a potentially curative treatment of chronic myeloid leukemia (CML). Optimal conditioning intensity for allo-HCT for CML in the era of tyrosine kinase inhibitors (TKIs) is unknown. Using the Center for International Blood and Marrow Transplant Research database, we sought to determine whether reduced-intensity/nonmyeloablative conditioning (RIC) allo-HCT and myeloablative conditioning (MAC) result in similar outcomes in CML patients. We evaluated 1395 CML allo-HCT recipients between the ages of 18 and 60 years. The disease status at transplant was divided into the following categories: chronic phase 1, chronic phase 2 or greater, and accelerated phase. Patients in blast phase at transplant and alternative donor transplants were excluded. The primary outcome was overall survival (OS) after allo-HCT. MAC (n = 1204) and RIC allo-HCT recipients (n = 191) from 2007 to 2014 were included. Patient, disease, and transplantation characteristics were similar, with a few exceptions. Multivariable analysis showed no significant difference in OS between MAC and RIC groups. In addition, leukemia-free survival and nonrelapse mortality did not differ significantly between the 2 groups. Compared with MAC, the RIC group had a higher risk of early relapse after allo-HCT (hazard ratio [HR], 1.85; P = .001). The cumulative incidence of chronic graft-versus-host disease (cGVHD) was lower with RIC than with MAC (HR, 0.77; P = .02). RIC provides similar survival and lower cGVHD compared with MAC and therefore may be a reasonable alternative to MAC for CML patients in the TKI era

    Association between the choice of the conditioning regimen and outcomes of allogeneic hematopoietic cell transplantation for myelofibrosis

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    Allogeneic hematopoietic cell transplantation (allo-HCT) remains the only curative treatment for myelofibrosis. However, the optimal conditioning regimen either with reduced intensity conditioning (RIC) or myeloablative conditioning (MAC) is not well known. Using the Center for International Blood and Marrow Transplant Research database, we identified adults aged ≥18 years with myelofibrosis undergoing allo-HCT between 2008-2019 and analyzed the outcomes separately in the RIC and MAC cohorts based on the conditioning regimens used. Among 872 eligible patients, 493 underwent allo-HCT using RIC (Fludarabine/busulfan=166, Fludarabine/melphalan=327) and 379 using MAC (Fludarabine/busulfan=247, Busulfan/cyclophosphamide=132). In multivariable analysis with RIC, Fludarabine/melphalan was associated with inferior overall survival (HR 1.80, 95% CI 1.15-2.81, p=0.009), higher early non-relapse mortality (HR 1.81, 95% CI 1.12-2.91, p=0.01) and higher acute graft versus host disease (GVHD) (grade II-IV- HR 1.45, 95% CI 1.03-2.03, p=0.03; grade III-IV HR 2.21, 95%CI 1.28-3.83, p=0.004) compared to Fludarabine/busulfan. In the MAC setting, Busulfan/cyclophosphamide was associated with a higher acute GVHD (grade II-IV HR 2.33, 95% CI 1.67-3.25, p\u3c0.001; grade III-IV HR 2.31, 95% CI 1.52-3.52, p\u3c0.001) and inferior GVHD-free relapse-free survival (GRFS) (HR 1.94, 95% CI 1.49-2.53, p\u3c0.001) as compared to Fludarabine/busulfan. Hence, our study suggests that Fludarabine/busulfan is associated with better outcomes in RIC (better overall survival, lower early non-relapse mortality, lower acute GVHD) and MAC (lower acute GVHD and better GRFS) in myelofibrosis
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