31 research outputs found
Common and Low Frequency Variants in MERTK Are Independently Associated with Multiple Sclerosis Susceptibility with Discordant Association Dependent upon HLA-DRB1*15:01 Status
Common and low Frequency variants in MERTK are independently associated with multiple sclerosis susceptibility with discordant association dependent upon HLA-DRB1*15:01 status
Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. The risk of developing MS is strongly influenced by genetic predisposition, and over 100 loci have been established as associated with susceptibility. However, the biologically relevant variants underlying disease risk have not been defined for the vast majority of these loci, limiting the power of these genetic studies to define new avenues of research for the development of MS therapeutics. It is therefore crucial that candidate MS susceptibility loci are carefully investigated to identify the biological mechanism linking genetic polymorphism at a given gene to the increased chance of developing MS. MERTK has been established as an MS susceptibility gene and is part of a family of receptor tyrosine kinases known to be involved in the pathogenesis of demyelinating disease. In this study we have refined the association of MERTK with MS risk to independent signals from both common and low frequency variants. One of the associated variants was also found to be linked with increased expression of MERTK in monocytes and higher expression of MERTK was associated with either increased or decreased risk of developing MS, dependent upon HLA-DRB1*15:01 status. This discordant association potentially extended beyond MS susceptibility to alterations in disease course in established MS. This study provides clear evidence that distinct polymorphisms within MERTK are associated with MS susceptibility, one of which has the potential to alter MERTK transcription, which in turn can alter both susceptibility and disease course in MS patients
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Plant pest surveillance: from satellites to molecules
Plant pests and diseases impact both food security and natural ecosystems, and the impact has been accelerated in recent years due to several confounding factors. The globalisation of trade has moved pests out of natural ranges, creating damaging epidemics in new regions. Climate change has extended the range of pests and the pathogens they vector. Resistance to agrochemicals has made pathogens, pests, and weeds more difficult to control. Early detection is critical to achieve effective control, both from a biosecurity as well as an endemic pest perspective. Molecular diagnostics has revolutionised our ability to identify pests and diseases over the past two decades, but more recent technological innovations are enabling us to achieve better pest surveillance. In this review, we will explore the different technologies that are enabling this advancing capability and discuss the drivers that will shape its future deployment
Level of agreement between frequently used cardiovascular risk calculators in people living with HIV
Objectives
The aim of the study was to describe agreement between the QRISK2, Framingham and Data Collection on Adverse Events of AntiâHIV Drugs (D:A:D) cardiovascular disease (CVD) risk calculators in a large UK study of people living with HIV (PLWH).
Methods
PLWH enrolled in the Pharmacokinetic and Clinical Observations in People over Fifty (POPPY) study without a prior CVD event were included in this study. QRISK2, Framingham CVD and the full and reduced D:A:D CVD scores were calculated; participants were stratified into âlowâ ( 20%) categories for each. Agreement between scores was assessed using weighted kappas and BlandâAltman plots.
Results
The 730 included participants were predominantly male (636; 87.1%) and of white ethnicity (645; 88.5%), with a median age of 53 [interquartile range (IQR) 49â59] years. The median calculated 10âyear CVD risk was 11.9% (IQR 6.8â18.4%), 8.9% (IQR 4.6â15.0%), 8.5% (IQR 4.8â14.6%) and 6.9% (IQR 4.1â11.1%) when using the Framingham, QRISK2, and full and reduced D:A:D scores, respectively. Agreement between the different scores was generally moderate, with the highest level of agreement being between the Framingham and QRISK2 scores (weighted kappa = 0.65) but with most other kappa coefficients in the 0.50â0.60 range.
Conclusions
Estimates of predicted 10âyear CVD risk obtained with commonly used CVD risk prediction tools demonstrate, in general, only moderate agreement among PLWH in the UK. While further validation with clinical endpoints is required, our findings suggest that care should be taken when interpreting any score alone
Depression, lifestyle factors and cognitive function in people living with HIV and comparable HIV-negative controls
We investigated whether differences in cognitive performance between people living with HIV (PLWH) and comparable HIV-negative people were mediated or moderated by depressive symptoms and lifestyle factors.
METHODS:
A cross-sectional study of 637 'older' PLWH aged â„ 50 years, 340 'younger' PLWH aged < 50 years and 276 demographically matched HIV-negative controls aged â„ 50 years enrolled in the Pharmacokinetic and Clinical Observations in People over Fifty (POPPY) study was performed. Cognitive function was assessed using a computerized battery (CogState). Scores were standardized into Z-scores [mean = 0; standard deviation (SD) = 1] and averaged to obtain a global Z-score. Depressive symptoms were evaluated via the Patient Health Questionnaire (PHQ-9). Differences between the three groups and the effects of depression, sociodemographic factors and lifestyle factors on cognitive performance were evaluated using median regression. All analyses accounted for age, gender, ethnicity and level of education.
RESULTS:
After adjustment for sociodemographic factors, older and younger PLWH had poorer overall cognitive scores than older HIV-negative controls (P < 0.001 and P = 0.006, respectively). Moderate or severe depressive symptoms were more prevalent in both older (27%; P < 0.001) and younger (21%; P < 0.001) PLWH compared with controls (8%). Depressive symptoms (P < 0.001) and use of hashish (P = 0.01) were associated with lower cognitive function; alcohol consumption (P = 0.02) was associated with better cognitive scores. After further adjustment for these factors, the difference between older PLWH and HIV-negative controls was no longer significant (P = 0.08), while that between younger PLWH and older HIV-negative controls remained significant (P = 0.01).
CONCLUSIONS:
Poorer cognitive performances in PLWH compared with HIV-negative individuals were, in part, mediated by the greater prevalence of depressive symptoms and recreational drug use reported by PLWH
Plasticity in foraging strategies of inshore birds: how Little Penguins maintain body reserves while feeding offspring.
International audienceBreeding animals face important time and energy constraints when caring for themselves and their offspring. For long-lived species, life-history theory predicts that parents should favor survival over current reproductive attempts, thus investing more into their own maintenance than the provisioning of their young. In seabirds, provisioning strategies may additionally be influenced by the distance between breeding sites and foraging areas, and offshore and inshore species should thus exhibit different strategies. Here, we examine the provisioning strategies of an inshore seabird using a long-term data set on more than 200 Little Penguins, Eudyptula minor. They alternated between two consecutive long and several short foraging trips all along chick rearing, a strategy almost never observed for inshore animals. Short trips allowed for regular provisioning of the chicks (high feeding frequency and larger meals), whereas long trips were performed when parent body mass was low and enabled them to rebuild their reserves, suggesting that adult body condition may be a key factor in initiating long trips. Inshore seabirds do use dual strategies of alternating short and long trips, but from our data, on a simpler and less flexible way than for offshore birds
Appendix A. Histogram of foraging-trip duration in chick-rearing Little Penguins.
Histogram of foraging-trip duration in chick-rearing Little Penguins
Satellite tag deployment details and movement descriptors from the filtered Argos location data.
<p>Satellite tag deployment details and movement descriptors from the filtered Argos location data.</p
Pygmy blue whale migration (nâ=â11) towards Indonesia in relation to 2° bins of latitude.
<p>a) Distance to coastline (km), b) bathymetric depth (m) and c) distance travelled per day (km). All bars represent mean values with 95% confidence intervals. Map of Australia is included to indicate the position of each longitudinal bin in relation to the Australian and Indonesian coastline.</p
Filtered satellite tag derived locations of pygmy blue whales (nâ=â11) by month.
<p>Individuals were tagged in March (2011: nâ=â7) and April (2009: nâ=â3; 2011: nâ=â1) in the Perth Canyon. The northern terminus of migration occurred in Indonesia. A single whale was tracked intermittently until February 2012 at which time it was located in the subtropical frontal zone.</p