24 research outputs found
Multiple Multilocus DNA Barcodes from the Plastid Genome Discriminate Plant Species Equally Well
A universal barcode system for land plants would be a valuable resource, with potential utility in fields as diverse as ecology, floristics, law enforcement and industry. However, the application of plant barcoding has been constrained by a lack of consensus regarding the most variable and technically practical DNA region(s). We compared eight candidate plant barcoding regions from the plastome and one from the mitochondrial genome for how well they discriminated the monophyly of 92 species in 32 diverse genera of land plants (N = 251 samples). The plastid markers comprise portions of five coding (rpoB, rpoC1, rbcL, matK and 23S rDNA) and three non-coding (trnH-psbA, atpF–atpH, and psbK–psbI) loci. Our survey included several taxonomically complex groups, and in all cases we examined multiple populations and species. The regions differed in their ability to discriminate species, and in ease of retrieval, in terms of amplification and sequencing success. Single locus resolution ranged from 7% (23S rDNA) to 59% (trnH-psbA) of species with well-supported monophyly. Sequence recovery rates were related primarily to amplification success (85–100% for plastid loci), with matK requiring the greatest effort to achieve reasonable recovery (88% using 10 primer pairs). Several loci (matK, psbK–psbI, trnH-psbA) were problematic for generating fully bidirectional sequences. Setting aside technical issues related to amplification and sequencing, combining the more variable plastid markers provided clear benefits for resolving species, although with diminishing returns, as all combinations assessed using four to seven regions had only marginally different success rates (69–71%; values that were approached by several two- and three-region combinations). This performance plateau may indicate fundamental upper limits on the precision of species discrimination that is possible with DNA barcoding systems that include moderate numbers of plastid markers. Resolution to the contentious debate on plant barcoding should therefore involve increased attention to practical issues related to the ease of sequence recovery, global alignability, and marker redundancy in multilocus plant DNA barcoding systems
Long-term follow-up of IPEX syndrome patients after different therapeutic strategies : an international multicenter retrospective study
Background: Immunodysregulation polyendocrinopathy enteropathy x-linked(IPEX) syndrome is a monogenic autoimmune disease caused by FOXP3 mutations. Because it is a rare disease, the natural history and response to treatments, including allogeneic hematopoietic stem cell transplantation (HSCT) and immunosuppression (IS), have not been thoroughly examined.
Objective: This analysis sought to evaluate disease onset, progression, and long-term outcome of the 2 main treatments in long-term IPEX survivors.
Methods: Clinical histories of 96 patients with a genetically proven IPEX syndrome were collected from 38 institutions worldwide and retrospectively analyzed. To investigate possible factors suitable to predict the outcome, an organ involvement (OI) scoring system was developed.
Results: We confirm neonatal onset with enteropathy, type 1 diabetes, and eczema. In addition, we found less common manifestations in delayed onset patients or during disease evolution. There is no correlation between the site of mutation and the disease course or outcome, and the same genotype can present with variable phenotypes. HSCT patients (n = 58) had a median follow-up of 2.7 years (range, 1 week-15 years). Patients receiving chronic IS (n 5 34) had a median follow-up of 4 years (range, 2 months-25 years). The overall survival after HSCT was 73.2% (95% CI, 59.4-83.0) and after IS was 65.1% (95% CI, 62.8-95.8). The pretreatment OI score was the only significant predictor of overall survival after transplant (P = .035) but not under IS.
Conclusions: Patients receiving chronic IS were hampered by disease recurrence or complications, impacting long-term.disease-free survival. When performed in patients with a low OI score, HSCT resulted in disease resolution with better quality of life, independent of age, donor source, or conditioning regimen
Lentiviral hematopoietic stem cell gene therapy for X-linked severe combined immunodeficiency
-linked severe combined immunodeficiency (SCID-X1) is a profound deficiency of T, B, and natural killer (NK) cell immunity caused by mutations in IL2RG encoding the common chain (γc) of several interleukin receptors. Gamma-retroviral (γRV) gene therapy of SCID-X1 infants without conditioning restores T cell immunity without B or NK cell correction, but similar treatment fails in older SCID-X1 children. We used a lentiviral gene therapy approach to treat five SCID-X1 patients with persistent immune dysfunction despite haploidentical hematopoietic stem cell (HSC) transplant in infancy. Follow-up data from two older patients demonstrate that lentiviral vector γc transduced autologous HSC gene therapy after nonmyeloablative busulfan conditioning achieves selective expansion of gene-marked T, NK, and B cells, which is associated with sustained restoration of humoral responses to immunization and clinical improvement at 2 to 3 years after treatment. Similar gene marking levels have been achieved in three younger patients, albeit with only 6 to 9 months of follow-up. Lentiviral gene therapy with reduced-intensity conditioning appears safe and can restore humoral immune function to posthaploidentical transplant older patients with SCID-X1
Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans
Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have
fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in
25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16
regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of
correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP,
while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in
Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium
(LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region.
Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant
enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the
refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa,
an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of
PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent
signals within the same regio
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Safe and Effective Prophylaxis with Bimonthly Intravenous Pentamidine in the Pediatric Hematopoietic Stem Cell Transplant Population.
BackgroundWithout prophylaxis, Pneumocystis jiroveci pneumonia (PCP) develops in 5%-15% of pediatric hematopoietic stem cell transplant (HCT) patients with mortality above 50%. Trimethoprim-sulfamethoxazole is a standard PCP prophylaxis; pentamidine is frequently used as second-line prophylaxis because of trimethoprim-sulfamethoxazole's potential for cytopenias. Monthly intravenous (IV) pentamidine has variable efficacy with PCP infection rates of 0%-10% in pediatric patients, and higher breakthrough rates in those younger than 2 years. We hypothesized that bimonthly (twice monthly) pentamidine might have equivalent safety and improved efficacy; therefore, we conducted a retrospective analysis of bimonthly pentamidine PCP prophylaxis.MethodsWe retrospectively reviewed records of all pediatric HCT patients who received bimonthly IV pentamidine between December 2006 and June 2013, and collected data regarding demographics, clinical course, prophylaxis rationale, laboratory values and adverse events.ResultsBetween December 2006 and June 2013, 111 pediatric HCT patients received bimonthly IV pentamidine (574 doses, 8758 patient-days); 31 patients were younger than 2 years at initiation. In the majority (53% of courses), pentamidine was initiated because of cytopenias. Fourteen patients (12.6% of patients, 2.4% of doses) experienced a side-effect prompting discontinuation, including 3 patients with infusion-related hypotension/anaphylaxis and 3 with acute pancreatic dysfunction. No patients [0% (95% confidence interval: 0-3.2)] developed PCP during or after bimonthly IV pentamidine prophylaxis.ConclusionsBimonthly IV pentamidine for PCP prophylaxis in the HCT pediatric population has comparable safety to monthly IV pentamidine and was highly effective, including in the very young. Bimonthly IV pentamidine should be considered in pediatric patients as second-line PCP prophylaxis
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Safe and Effective Prophylaxis with Bimonthly Intravenous Pentamidine in the Pediatric Hematopoietic Stem Cell Transplant Population
BackgroundWithout prophylaxis, Pneumocystis jiroveci pneumonia (PCP) develops in 5%-15% of pediatric hematopoietic stem cell transplant (HCT) patients with mortality above 50%. Trimethoprim-sulfamethoxazole is a standard PCP prophylaxis; pentamidine is frequently used as second-line prophylaxis because of trimethoprim-sulfamethoxazole's potential for cytopenias. Monthly intravenous (IV) pentamidine has variable efficacy with PCP infection rates of 0%-10% in pediatric patients, and higher breakthrough rates in those younger than 2 years. We hypothesized that bimonthly (twice monthly) pentamidine might have equivalent safety and improved efficacy; therefore, we conducted a retrospective analysis of bimonthly pentamidine PCP prophylaxis.MethodsWe retrospectively reviewed records of all pediatric HCT patients who received bimonthly IV pentamidine between December 2006 and June 2013, and collected data regarding demographics, clinical course, prophylaxis rationale, laboratory values and adverse events.ResultsBetween December 2006 and June 2013, 111 pediatric HCT patients received bimonthly IV pentamidine (574 doses, 8758 patient-days); 31 patients were younger than 2 years at initiation. In the majority (53% of courses), pentamidine was initiated because of cytopenias. Fourteen patients (12.6% of patients, 2.4% of doses) experienced a side-effect prompting discontinuation, including 3 patients with infusion-related hypotension/anaphylaxis and 3 with acute pancreatic dysfunction. No patients [0% (95% confidence interval: 0-3.2)] developed PCP during or after bimonthly IV pentamidine prophylaxis.ConclusionsBimonthly IV pentamidine for PCP prophylaxis in the HCT pediatric population has comparable safety to monthly IV pentamidine and was highly effective, including in the very young. Bimonthly IV pentamidine should be considered in pediatric patients as second-line PCP prophylaxis
Safe and Effective Prophylaxis with Bimonthly Intravenous Pentamidine in the Pediatric Hematopoietic Stem Cell Transplant Population
BackgroundWithout prophylaxis, Pneumocystis jiroveci pneumonia (PCP) develops in 5%-15% of pediatric hematopoietic stem cell transplant (HCT) patients with mortality above 50%. Trimethoprim-sulfamethoxazole is a standard PCP prophylaxis; pentamidine is frequently used as second-line prophylaxis because of trimethoprim-sulfamethoxazole's potential for cytopenias. Monthly intravenous (IV) pentamidine has variable efficacy with PCP infection rates of 0%-10% in pediatric patients, and higher breakthrough rates in those younger than 2 years. We hypothesized that bimonthly (twice monthly) pentamidine might have equivalent safety and improved efficacy; therefore, we conducted a retrospective analysis of bimonthly pentamidine PCP prophylaxis.MethodsWe retrospectively reviewed records of all pediatric HCT patients who received bimonthly IV pentamidine between December 2006 and June 2013, and collected data regarding demographics, clinical course, prophylaxis rationale, laboratory values and adverse events.ResultsBetween December 2006 and June 2013, 111 pediatric HCT patients received bimonthly IV pentamidine (574 doses, 8758 patient-days); 31 patients were younger than 2 years at initiation. In the majority (53% of courses), pentamidine was initiated because of cytopenias. Fourteen patients (12.6% of patients, 2.4% of doses) experienced a side-effect prompting discontinuation, including 3 patients with infusion-related hypotension/anaphylaxis and 3 with acute pancreatic dysfunction. No patients [0% (95% confidence interval: 0-3.2)] developed PCP during or after bimonthly IV pentamidine prophylaxis.ConclusionsBimonthly IV pentamidine for PCP prophylaxis in the HCT pediatric population has comparable safety to monthly IV pentamidine and was highly effective, including in the very young. Bimonthly IV pentamidine should be considered in pediatric patients as second-line PCP prophylaxis
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Current Knowledge and Priorities for Future Research in Late Effects after Hematopoietic Stem Cell Transplantation (HCT) for Severe Combined Immunodeficiency Patients: A Consensus Statement from the Second Pediatric Blood and Marrow Transplant Consortium International Conference on Late Effects after Pediatric HCT.
Severe combined immunodeficiency (SCID) is 1 of the most common indications for pediatric hematopoietic cell transplantation (HCT) in patients with primary immunodeficiency. Historically, SCID was diagnosed in infants who presented with opportunistic infections within the first year of life. With newborn screening (NBS) for SCID in most of the United States, the majority of infants with SCID are now diagnosed and treated in the first 3.5 months of life; however, in the rest of the world, the lack of NBS means that most infants with SCID still present with infections. The average survival for SCID patients who have undergone transplantation currently is >70% at 3 years after transplantation, although this can vary significantly based on multiple factors, including age and infection status at the time of transplantation, type of donor source utilized, manipulation of graft before transplantation, graft-versus-host disease prophylaxis, type of conditioning (if any) utilized, and underlying genotype of SCID. In at least 1 study of SCID patients who received no conditioning, long-term survival was 77% at 8.7 years (range out to 26 years) after transplantation. Although a majority of patients with SCID will engraft T cells without any conditioning therapy, depending on genotype, donor source, HLA match, and presence of circulating maternal cells, a sizable percentage of these will fail to achieve full immune reconstitution. Without conditioning, T cell reconstitution typically occurs, although not always fully, whereas B cell engraftment does not, leaving some molecular types of SCID patients with intrinsically defective B cells, in most cases, dependent on regular infusions of immunoglobulin. Because of this, many centers have used conditioning with alkylating agents including busulfan or melphalan known to open marrow niches in attempts to achieve B cell reconstitution. Thus, it is imperative that we understand the potential late effects of these agents in this patient population. There are also nonimmunologic risks associated with HCT for SCID that appear to be dependent upon the genotype of the patient. In this report, we have evaluated the published data on late effects and attempted to summarize the known risks associated with conditioning and alternative donor sources. These data, while informative, are also a clear demonstration that there is still much to be learned from the SCID population in terms of their post-HCT outcomes. This paper will summarize current findings and recommend further research in areas considered high priority. Specific guidelines regarding a recommended approach to long-term follow-up, including laboratory and clinical monitoring, will be forthcoming in a subsequent paper
Challenges and Opportunities for International Cooperative Studies in Pediatric Hematopoeitic Cell Transplantation: Priorities of the Westhafen Intercontinental Group
More than 20% of allogeneic hematopoietic cell transplantations (HCTs) are performed in children and adolescents at a large number of relatively small centers. Unlike adults, at least one-third of HCTs in children are performed for rare, nonmalignant indications. Clinical trials to improve HCT outcomes in children have been limited by small numbers and these pediatric-specific features. The need for a larger number of pediatric HCT centers to participate in trials has led to the involvement of international collaborative groups. Representatives of the Pediatric Blood and Marrow Transplant Consortium, European Group for Blood and Marrow Transplantation's Pediatric Working Group, International Berlin-Frankfurt-Munster (iBFm) Stem Cell Transplantation Committee, and Children's Oncology Group's Hematopoietic Stem Cell Transplantation Discipline Committee met on October 3, 2012, in Frankfurt, Germany to develop a consensus on the highest priorities in pediatric HCT. In addition, it explored the creation of an international consortium to develop studies focused on HCT in children and adolescents. This meeting led to the creation of an international HCT network, dubbed the Westhafen Intercontinental Group, to develop worldwide priorities and strategies to address pediatric HCT issues. This review outlines the priorities of need as identified by this consensus group