120 research outputs found

    Crosstalk between hemostasis inhibitors and cholesterol biomarkers in multiple sclerosis

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    The individual roles of cholesterol pathway biomarkers (CPB) and hemostasis inhibitors with neuroimaging outcomes were previously investigated in multiple sclerosis (MS). The purpose of this extension study was to investigate potential crosstalk between plasma CPB [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and apolipoproteins (Apo) ApoA-I, ApoAII, ApoB, ApoC-II and ApoE] and hemostasis inhibitors [heparin cofactor-II (HCII), protein C (PC), protein S (PS), thrombomodulin, ADAMTS13 and PAI-1] in a cohort of 127 MS patients, and 40 healthy individuals (HI). The associations were assessed with regressions. In MS patients, HCII was positively associated with TC, LDL-C, HDL-C and ApoA-I (p=0.028, 0.027, 0.002 and 0.027, respectively) but negatively associated with ApoCII (p=0.018). PC was positively associated with ApoC-II (p=0.001) and ApoB (p=0.016) whereas PS was associated with TC (p=0.024) and ApoE (p=0.003) in MS. The ApoC-II associations were not observed in HI. The negative association between ApoC-II and HCll was an exception amongst other positive associations between CPB and hemostasis inhibitors in MS. CPB do not modulate the PC associations with neurodegeneration in MS

    Crosstalk between hemostasis inhibitors and cholesterol biomarkers in multiple sclerosis

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    The individual roles of cholesterol pathway biomarkers (CPB) and hemostasis inhibitors with neuroimaging outcomes were previously investigated in multiple sclerosis (MS). The purpose of this extension study was to investigate potential crosstalk between plasma CPB [total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and apolipoproteins (Apo) ApoA-I, ApoAII, ApoB, ApoC-II and ApoE] and hemostasis inhibitors [heparin cofactor-II (HCII), protein C (PC), protein S (PS), thrombomodulin, ADAMTS13 and PAI-1] in a cohort of 127 MS patients, and 40 healthy individuals (HI). The associations were assessed with regressions. In MS patients, HCII was positively associated with TC, LDL-C, HDL-C and ApoA-I (p=0.028, 0.027, 0.002 and 0.027, respectively) but negatively associated with ApoCII (p=0.018). PC was positively associated with ApoC-II (p=0.001) and ApoB (p=0.016) whereas PS was associated with TC (p=0.024) and ApoE (p=0.003) in MS. The ApoC-II associations were not observed in HI. The negative association between ApoC-II and HCll was an exception amongst other positive associations between CPB and hemostasis inhibitors in MS. CPB do not modulate the PC associations with neurodegeneration in MS

    Testing a novel sensor design to jointly measure cosmic-ray neutrons, muons and gamma rays for non-invasive soil moisture estimation

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    Cosmic-ray neutron sensing (CRNS) has emerged as a reliable method for soil moisture and snow estimation. However, the applicability of this method beyond research has been limited due to, among others, the use of relatively large and expensive sensors. This paper presents the tests conducted on a new scintillator-based sensor especially designed to jointly measure neutron counts, muons and total gamma rays. The neutron signal is first compared against two conventional gas-tube-based CRNS sensors at two locations. The estimated soil moisture is further assessed at four agricultural sites, based on gravimetric soil moisture collected within the sensor footprint. Muon fluxes are compared to the incoming neutron variability measured at a neutron monitoring station and total gammas counts are compared to the signal detected by a gamma ray spectrometer. The results show that the neutron dynamic detected by the new scintillator-based CRNS sensor is well in agreement with conventional CRNS sensors. The derived soil moisture also agreed well with the gravimetric soil moisture measurements. The muons and the total gamma rays simultaneously detected by the sensor show promising features to account for the incoming variability and for discriminating irrigation and precipitation events, respectively. Further experiments and analyses should be conducted, however, to better understand the accuracy and the added value of these additional data for soil moisture estimation. Overall, the new scintillator design shows to be a valid and compact alternative to conventional CRNS sensors for non-invasive soil moisture monitoring and to open the path to a wide range of applications.</p

    Protein S on the surface of plasma lipoproteins: a potential mechanism for protein S delivery to the atherosclerotic plaques?

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    The anticoagulant protein S (PS) binds phospholipids with very high affinity, but PS interaction with lipoproteins and lipidrich atherosclerotic plaques remains still poorly defined. We investigated PS in plasma lipoproteins and in atherosclerotic plaques from ten patients undergoing endarterectomy. PS was detected by Western blotting after exposure of the necrotic core to liposomes and was found to maintain its ability to bind phosphatidylserine micelles. The amounts of PS bound to low/very low-density lipoproteins in patient' plasmas were higher and more variable than those detected in healthy subjects. A direct correlation between bound PS and low-density lipoproteins (LDL), plasma levels was found only in patients (r=0.921, p<0.001), thereby leading to hypothesize that the PS-phospholipids binding may increase by oxidative processes of LDL in atherosclerotic patients. The presence of the PS into the necrotic core of atherosclerotic plaques and on the surface of lipoproteins, particularly the atherogenic LDL, suggests a LDL-based delivery of PS to the atherosclerotic plaques and emphasizes the deep link between plasma lipids and coagulation in cardiovascular diseases

    Epidemiology and complications of late-onset sepsis: an Italian area-based study

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    BACKGROUND: Most studies regarding late-onset sepsis (LOS) address selected populations (i.e., neonates with low birth weight or extremely preterm neonates). Studying all age groups is more suitable to assess the burden of single pathogens and their clinical relevance. METHODS: This is a retrospective regional study involving paediatric departments and NICUs in Emilia-Romagna (Italy). Regional laboratory databases were searched from 2009 to 2012. Records of infants (aged 4 to 90 days) with a positive blood or cerebrospinal fluid (CSF) culture were retrospectively reviewed and analysed according to acquisition mode (whether hospital- or community-acquired). RESULTS: During the study period, there were 146,682 live births (LBs), with 296 patients experiencing 331 episodes of LOS (incidence rate: 2.3/1000 LBs). Brain lesions upon discharge from the hospital were found in 12.3% (40/296) of cases, with death occurring in 7.1% (23/296; 0.14/1000 LBs). With respect to full-term neonates, extremely preterm or extremely low birth weight neonates had very high risk of LOS and related mortality (&gt; 100- and &gt; 800-fold higher respectively). Hospital-acquired LOS (n = 209) was significantly associated with very low birth weight, extremely preterm birth, pneumonia, mechanical ventilation, and death (p&lt; 0.01). At multivariate logistic regression analysis, catecholamine support (OR = 3.2), central venous line before LOS (OR = 14.9), and meningitis (OR = 44.7) were associated with brain lesions or death in hospital-acquired LOS (area under the ROC curve 0.81, H-L p = 0.41). Commonly identified pathogens included coagulase-negative staphylococci (CoNS n = 71, 21.4%), Escherichia coli (n = 50, 15.1%), Staphylococcus aureus (n = 41, 12.4%) and Enterobacteriaceae (n = 41, 12.4%). Group B streptococcus was the predominant cause of meningitis (16 of 38 cases, 42%). Most pathogens were sensitive to first line antibiotics. CONCLUSIONS: This study provides the first Italian data regarding late-onset sepsis (LOS) in all gestational age groups. Compared to full-term neonates, very high rates of LOS and mortality occurred in neonates with a lower birth weight and gestational age. Group B streptococcus was the leading cause of meningitis. Excluding CoNS, the predominant pathogens were Escherichia coli and Staphylococcus aureus. Neonates with hospital-acquired LOS had a worse outcome. Antibiotic associations, recommended for empirical treatment of hospital- or community-acquired LOS, were adequate

    Performance of the model for end-stage liver disease score for mortality prediction and the potential role of etiology

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    Bakground &amp; aims Although discrimination of the model for end stage liver disease (MELD) is generally considered acceptable, its calibration is still unclear. In a validation study, we assessed the discrimination and calibration performance of 3 versions of the model: original MELD-TIPS, used to predict survival after transjugular intra-hepatic portosystemic shunt (TIPS); classic MELD-Mayo; MELD-UNOS, used by United Network for Organ Sharing (UNOS). Recalibration and model updating were also explored. Methods 776 patients submitted to elective TIPS (TIPS cohort), and 445 unselected patients (non-TIPS cohort) were included. Three, 6 and 12-month mortality predictions were calculated by the 3 MELD versions: discrimination was assessed by c-statistics and calibration by comparing deciles of predicted and observed risks. Cox and Fine and Grey models were used for recalibration and prognostic analyses. Results Major patient characteristics in TIPS/non-TIPS cohorts were: viral etiology 402/188, alcoholic 185/130, NASH 65/33; mean follow-up± SD 25±9/19±21months; 3-6-12 month mortality were respectively, 57-102-142/31-47-99. C-statistics ranged from 0.66 to 0.72 in TIPS and 0.66 to 0.76 in non-TIPS cohorts across prediction times and scores. A post-hoc analysis revealed worse c-statistics in non-viral cirrhosis with more pronounced and significant worsening in non-TIPS cohort. Calibration was acceptable with MELD-TIPS but largely unsatisfactory with MELD-Mayo and -UNOS whose performance improved much after recalibration. A prognostic analysis showed that age, albumin, and TIPS indication might be used for a MELD updating. Conclusions In this validation study the MELD performance was largely unsatisfactory, particularly in non-viral cirrhosis. MELD recalibration and candidate variables for a MELD updating are proposed. Lay summary While discrimination performance of the Model for End Stage Liver Disease (MELD) is credited to be fair to good, its calibration, the correspondence of observed to predicted mortality, is still unsettled. We found that application of 3 different versions of the MELD in two independent cirrhosis cohorts yielded largely imprecise mortality predictions particularly in non-viral cirrhosis and propose a validated model recalibration. Candidate variables for a MELD updating are proposed

    An explainable model of host genetic interactions linked to COVID-19 severity

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    We employed a multifaceted computational strategy to identify the genetic factors contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing (WES) dataset of a cohort of 2000 Italian patients. We coupled a stratified k-fold screening, to rank variants more associated with severity, with the training of multiple supervised classifiers, to predict severity based on screened features. Feature importance analysis from tree-based models allowed us to identify 16 variants with the highest support which, together with age and gender covariates, were found to be most predictive of COVID-19 severity. When tested on a follow-up cohort, our ensemble of models predicted severity with high accuracy (ACC = 81.88%; AUCROC = 96%; MCC = 61.55%). Our model recapitulated a vast literature of emerging molecular mechanisms and genetic factors linked to COVID-19 response and extends previous landmark Genome-Wide Association Studies (GWAS). It revealed a network of interplaying genetic signatures converging on established immune system and inflammatory processes linked to viral infection response. It also identified additional processes cross-talking with immune pathways, such as GPCR signaling, which might offer additional opportunities for therapeutic intervention and patient stratification. Publicly available PheWAS datasets revealed that several variants were significantly associated with phenotypic traits such as "Respiratory or thoracic disease", supporting their link with COVID-19 severity outcome.A multifaceted computational strategy identifies 16 genetic variants contributing to increased risk of severe COVID-19 infection from a Whole Exome Sequencing dataset of a cohort of Italian patients

    Carriers of ADAMTS13 Rare Variants Are at High Risk of Life-Threatening COVID-19

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    Thrombosis of small and large vessels is reported as a key player in COVID-19 severity. However, host genetic determinants of this susceptibility are still unclear. Congenital Thrombotic Thrombocytopenic Purpura is a severe autosomal recessive disorder characterized by uncleaved ultra-large vWF and thrombotic microangiopathy, frequently triggered by infections. Carriers are reported to be asymptomatic. Exome analysis of about 3000 SARS-CoV-2 infected subjects of different severities, belonging to the GEN-COVID cohort, revealed the specific role of vWF cleaving enzyme ADAMTS13 (A disintegrin-like and metalloprotease with thrombospondin type 1 motif, 13). We report here that ultra-rare variants in a heterozygous state lead to a rare form of COVID-19 characterized by hyper-inflammation signs, which segregates in families as an autosomal dominant disorder conditioned by SARS-CoV-2 infection, sex, and age. This has clinical relevance due to the availability of drugs such as Caplacizumab, which inhibits vWF-platelet interaction, and Crizanlizumab, which, by inhibiting P-selectin binding to its ligands, prevents leukocyte recruitment and platelet aggregation at the site of vascular damage

    Gain- and Loss-of-Function CFTR Alleles Are Associated with COVID-19 Clinical Outcomes

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    Carriers of single pathogenic variants of the CFTR (cystic fibrosis transmembrane conductance regulator) gene have a higher risk of severe COVID-19 and 14-day death. The machine learning post-Mendelian model pinpointed CFTR as a bidirectional modulator of COVID-19 outcomes. Here, we demonstrate that the rare complex allele [G576V;R668C] is associated with a milder disease via a gain-of-function mechanism. Conversely, CFTR ultra-rare alleles with reduced function are associated with disease severity either alone (dominant disorder) or with another hypomorphic allele in the second chromosome (recessive disorder) with a global residual CFTR activity between 50 to 91%. Furthermore, we characterized novel CFTR complex alleles, including [A238V;F508del], [R74W;D1270N;V201M], [I1027T;F508del], [I506V;D1168G], and simple alleles, including R347C, F1052V, Y625N, I328V, K68E, A309D, A252T, G542*, V562I, R1066H, I506V, I807M, which lead to a reduced CFTR function and thus, to more severe COVID-19. In conclusion, CFTR genetic analysis is an important tool in identifying patients at risk of severe COVID-19

    A genome-wide association study for survival from a multi-centre European study identified variants associated with COVID-19 risk of death

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    : The clinical manifestations of SARS-CoV-2 infection vary widely among patients, from asymptomatic to life-threatening. Host genetics is one of the factors that contributes to this variability as previously reported by the COVID-19 Host Genetics Initiative (HGI), which identified sixteen loci associated with COVID-19 severity. Herein, we investigated the genetic determinants of COVID-19 mortality, by performing a case-only genome-wide survival analysis, 60 days after infection, of 3904 COVID-19 patients from the GEN-COVID and other European series (EGAS00001005304 study of the COVID-19 HGI). Using imputed genotype data, we carried out a survival analysis using the Cox model adjusted for age, age2, sex, series, time of infection, and the first ten principal components. We observed a genome-wide significant (P-value < 5.0 × 10-8) association of the rs117011822 variant, on chromosome 11, of rs7208524 on chromosome 17, approaching the genome-wide threshold (P-value = 5.19 × 10-8). A total of 113 variants were associated with survival at P-value < 1.0 × 10-5 and most of them regulated the expression of genes involved in immune response (e.g., CD300 and KLR genes), or in lung repair and function (e.g., FGF19 and CDH13). Overall, our results suggest that germline variants may modulate COVID-19 risk of death, possibly through the regulation of gene expression in immune response and lung function pathways
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