69 research outputs found
Whole-genome sequencing reveals host factors underlying critical COVID-19
Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease
Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures
Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo
Multiancestry analysis of the HLA locus in Alzheimer’s and Parkinson’s diseases uncovers a shared adaptive immune response mediated by HLA-DRB1*04 subtypes
Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson’s disease (PD) and Alzheimer’s disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1*04 subtypes best accounted for the association, strongest with HLA-DRB1*04:04 and HLA-DRB1*04:07, and intermediary with HLA-DRB1*04:01 and HLA-DRB1*04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1*04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1*04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues
Biomarker-based assessment of collagen cross-linking identifies patients at risk of heart failure more likely to benefit from spironolactone effects on left atrial remodelling. Insights from the HOMAGE clinical trial
Abstract
Aims
The HOMAGE randomized trial found that spironolactone reduced left atrial volume index (LAVI), E:A ratio, and a marker of collagen type I synthesis (procollagen type I C-terminal propeptide) in patients at risk of heart failure (HF). Previous trials showed that patients with HF, preserved ejection fraction and low serum collagen type I C-terminal telopeptide to matrix metalloproteinase-1 ratio (CITP:MMP-1), associated with high collagen cross-linking, had less improvement in diastolic function with spironolactone. We evaluated the interaction between serum CITP:MMP-1 and spironolactone on cardiac function in the HOMAGE trial.
Methods and results
Patients at risk of HF were randomized to spironolactone (n = 260) or not (n = 255). Blood sampling and echocardiography were done at baseline, one and nine months. CITP:MMP-1 was used as an indirect measure of collagen cross-linking. Higher baseline CITP:MMP-1 (i.e. lower collagen cross-linking) was associated with greater reductions in LAVI with spironolactone at both one (p = 0.003) and nine (p = 0.01) months, but no interaction was observed for E:A ratio. Spironolactone reduced LAVI after one and nine months only for those patients in the third tertile of CITP:MMP-1 (estimated lowest collagen cross-linking) [mean differencesspiro/control: −1.77 (95% confidence interval, CI −2.94 to −0.59) and −2.52 (95% CI −4.46 to −0.58) mL/m2; interaction pacross-tertiles = 0.005; interaction pthird tertile = 0.008] with a similar trend for N-terminal pro-B-type natriuretic peptide which was consistently reduced by spironolactone only in the lowest collagen cross-linking tertile [mean differencesspiro/control: −0.47 (95% CI −0.66 to −0.28) and −0.31 (95% CI −0.59 to −0.04) ng/L; interaction pacross-tertiles = 0.09; interaction pthird tertile < 0.001].
Conclusions
These findings suggest that, for patients at risk of HF, the effects of spironolactone on left atrial remodelling may be more prominent in patients with less collagen cross-linking (indirectly assessed by serum CITP:MMP-1).
Abstract
Patients at risk of heart failure from the HOMAGE clinical trial were classified according to the baseline degree of myocardial collagen cross-linking, non-invasively assessed by the serum collagen type I C-terminal telopeptide (CITP) to matrix metalloproteinase-1 (MMP-1) ratio (CITP:MMP-1). As highly cross-linked collagen fibres are more resistant to degradation and CITP is a cross-linked peptide, for a given MMP-1 quantity less CITP will be released and, subsequently, serum CITP:MMP-1 will be lower. Whereas patients with low collagen cross-linking (high CITP:MMP-1) benefit from the cardioprotective effects of treatment with spironolactone on left atrial remodelling [i.e. a decrease in left atrial volume index (LAVI)] and on N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, these beneficial effects are not found in patients with higher collagen cross-linking (low CITP:MMP-1)
Biomarker-based assessment of collagen cross-linking identifies patients at risk of heart failure more likely to benefit from spironolactone effects on left atrial remodelling. Insights from the HOMAGE clinical trial
Abstract
Aims
The HOMAGE randomized trial found that spironolactone reduced left atrial volume index (LAVI), E:A ratio, and a marker of collagen type I synthesis (procollagen type I C-terminal propeptide) in patients at risk of heart failure (HF). Previous trials showed that patients with HF, preserved ejection fraction and low serum collagen type I C-terminal telopeptide to matrix metalloproteinase-1 ratio (CITP:MMP-1), associated with high collagen cross-linking, had less improvement in diastolic function with spironolactone. We evaluated the interaction between serum CITP:MMP-1 and spironolactone on cardiac function in the HOMAGE trial.
Methods and results
Patients at risk of HF were randomized to spironolactone (n = 260) or not (n = 255). Blood sampling and echocardiography were done at baseline, one and nine months. CITP:MMP-1 was used as an indirect measure of collagen cross-linking. Higher baseline CITP:MMP-1 (i.e. lower collagen cross-linking) was associated with greater reductions in LAVI with spironolactone at both one (p = 0.003) and nine (p = 0.01) months, but no interaction was observed for E:A ratio. Spironolactone reduced LAVI after one and nine months only for those patients in the third tertile of CITP:MMP-1 (estimated lowest collagen cross-linking) [mean differencesspiro/control: −1.77 (95% confidence interval, CI −2.94 to −0.59) and −2.52 (95% CI −4.46 to −0.58) mL/m2; interaction pacross-tertiles = 0.005; interaction pthird tertile = 0.008] with a similar trend for N-terminal pro-B-type natriuretic peptide which was consistently reduced by spironolactone only in the lowest collagen cross-linking tertile [mean differencesspiro/control: −0.47 (95% CI −0.66 to −0.28) and −0.31 (95% CI −0.59 to −0.04) ng/L; interaction pacross-tertiles = 0.09; interaction pthird tertile < 0.001].
Conclusions
These findings suggest that, for patients at risk of HF, the effects of spironolactone on left atrial remodelling may be more prominent in patients with less collagen cross-linking (indirectly assessed by serum CITP:MMP-1).
Abstract
Patients at risk of heart failure from the HOMAGE clinical trial were classified according to the baseline degree of myocardial collagen cross-linking, non-invasively assessed by the serum collagen type I C-terminal telopeptide (CITP) to matrix metalloproteinase-1 (MMP-1) ratio (CITP:MMP-1). As highly cross-linked collagen fibres are more resistant to degradation and CITP is a cross-linked peptide, for a given MMP-1 quantity less CITP will be released and, subsequently, serum CITP:MMP-1 will be lower. Whereas patients with low collagen cross-linking (high CITP:MMP-1) benefit from the cardioprotective effects of treatment with spironolactone on left atrial remodelling [i.e. a decrease in left atrial volume index (LAVI)] and on N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels, these beneficial effects are not found in patients with higher collagen cross-linking (low CITP:MMP-1)
Evolution of genes and genomes on the Drosophila phylogeny
Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species
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