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15 result(s) for "McFarland, Alexandra"
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COVID-19 susceptibility and severity risks in a cross-sectional survey of over 500 000 US adults
ObjectivesThe enormous toll of the COVID-19 pandemic has heightened the urgency of collecting and analysing population-scale datasets in real time to monitor and better understand the evolving pandemic. The objectives of this study were to examine the relationship of risk factors to COVID-19 susceptibility and severity and to develop risk models to accurately predict COVID-19 outcomes using rapidly obtained self-reported data.DesignA cross-sectional study.SettingAncestryDNA customers in the USA who consented to research.ParticipantsThe AncestryDNA COVID-19 Study collected self-reported survey data on symptoms, outcomes, risk factors and exposures for over 563 000 adult individuals in the USA in just under 4 months, including over 4700 COVID-19 cases as measured by a self-reported positive test.ResultsWe replicated previously reported associations between several risk factors and COVID-19 susceptibility and severity outcomes, and additionally found that differences in known exposures accounted for many of the susceptibility associations. A notable exception was elevated susceptibility for men even after adjusting for known exposures and age (adjusted OR=1.36, 95% CI=1.19 to 1.55). We also demonstrated that self-reported data can be used to build accurate risk models to predict individualised COVID-19 susceptibility (area under the curve (AUC)=0.84) and severity outcomes including hospitalisation and critical illness (AUC=0.87 and 0.90, respectively). The risk models achieved robust discriminative performance across different age, sex and genetic ancestry groups within the study.ConclusionsThe results highlight the value of self-reported epidemiological data to rapidly provide public health insights into the evolving COVID-19 pandemic.
mtDNA heteroplasmy level and copy number indicate disease burden in m.3243A>G mitochondrial disease
Mitochondrial disease associated with the pathogenic m.3243A>G variant is a common, clinically heterogeneous, neurogenetic disorder. Using multiple linear regression and linear mixed modelling, we evaluated which commonly assayed tissue (blood N  = 231, urine N  = 235, skeletal muscle N  = 77) represents the m.3243A>G mutation load and mitochondrial DNA (mtDNA) copy number most strongly associated with disease burden and progression. m.3243A>G levels are correlated in blood, muscle and urine ( R 2  = 0.61–0.73). Blood heteroplasmy declines by ~2.3%/year; we have extended previously published methodology to adjust for age. In urine, males have higher mtDNA copy number and ~20% higher m.3243A>G mutation load; we present formulas to adjust for this. Blood is the most highly correlated mutation measure for disease burden and progression in m.3243A>G‐harbouring individuals; increasing age and heteroplasmy contribute ( R 2  = 0.27, P  < 0.001). In muscle, heteroplasmy, age and mtDNA copy number explain a higher proportion of variability in disease burden ( R 2  = 0.40, P  < 0.001), although activity level and disease severity are likely to affect copy number. Whilst our data indicate that age‐corrected blood m.3243A>G heteroplasmy is the most convenient and reliable measure for routine clinical assessment, additional factors such as mtDNA copy number may also influence disease severity. Synopsis The m.3243A>G pathogenic mtDNA variant is associated with a highly heterogeneous multisystem disorder and varying mutation levels across tissues. In this study, mutation levels were characterised in three commonly sampled tissues ‐ blood, urine, skeletal muscle ‐ and correlated with disease burden. Urine m.3243A>G heteroplasmy levels display more variability than blood levels and must be corrected for a ˜20% lower level in females. Blood m.3243A>G heteroplasmy levels must be corrected for a decline of ˜2.3% per year. Disease burden and progression are more strongly associated with blood m.3243A>G heteroplasmy levels than urine levels. 27% of the variance in disease burden can be attributed to blood m.3243A>G heteroplasmy and age. Age, m.3243A>G heteroplasmy level and mtDNA copy number in skeletal muscle explain 40% of the variance in disease burden. Graphical Abstract The m.3243A>G pathogenic mtDNA variant is associated with a highly heterogeneous multisystem disorder and varying mutation levels across tissues. In this study, mutation levels were characterised in three commonly sampled tissues ‐ blood, urine, skeletal muscle ‐ and correlated with disease burden.
De novo mtDNA point mutations are common and have a low recurrence risk
BackgroundSevere, disease-causing germline mitochondrial (mt)DNA mutations are maternally inherited or arise de novo. Strategies to prevent transmission are generally available, but depend on recurrence risks, ranging from high/unpredictable for many familial mtDNA point mutations to very low for sporadic, large-scale single mtDNA deletions. Comprehensive data are lacking for de novo mtDNA point mutations, often leading to misconceptions and incorrect counselling regarding recurrence risk and reproductive options. We aim to study the relevance and recurrence risk of apparently de novo mtDNA point mutations.MethodsSystematic study of prenatal diagnosis (PND) and recurrence of mtDNA point mutations in families with de novo cases, including new and published data. ‘De novo’ based on the absence of the mutation in multiple (postmitotic) maternal tissues is preferred, but mutations absent in maternal blood only were also included.ResultsIn our series of 105 index patients (33 children and 72 adults) with (likely) pathogenic mtDNA point mutations, the de novo frequency was 24.6%, the majority being paediatric. PND was performed in subsequent pregnancies of mothers of four de novo cases. A fifth mother opted for preimplantation genetic diagnosis because of a coexisting Mendelian genetic disorder. The mtDNA mutation was absent in all four prenatal samples and all 11 oocytes/embryos tested. A literature survey revealed 137 de novo cases, but PND was only performed for 9 (including 1 unpublished) mothers. In one, recurrence occurred in two subsequent pregnancies, presumably due to germline mosaicism.ConclusionsDe novo mtDNA point mutations are a common cause of mtDNA disease. Recurrence risk is low. This is relevant for genetic counselling, particularly for reproductive options. PND can be offered for reassurance.
Gut CD4+ T cell phenotypes are a continuum molded by microbes, not by TH archetypes
CD4 + effector lymphocytes (T eff ) are traditionally classified by the cytokines they produce. To determine the states that T eff cells actually adopt in frontline tissues in vivo, we applied single-cell transcriptome and chromatin analyses to colonic T eff cells in germ-free or conventional mice or in mice after challenge with a range of phenotypically biasing microbes. Unexpected subsets were marked by the expression of the interferon (IFN) signature or myeloid-specific transcripts, but transcriptome or chromatin structure could not resolve discrete clusters fitting classic helper T cell (T H ) subsets. At baseline or at different times of infection, transcripts encoding cytokines or proteins commonly used as T H markers were distributed in a polarized continuum, which was functionally validated. Clones derived from single progenitors gave rise to both IFN-γ- and interleukin (IL)-17-producing cells. Most of the transcriptional variance was tied to the infecting agent, independent of the cytokines produced, and chromatin variance primarily reflected activities of activator protein (AP)-1 and IFN-regulatory factor (IRF) transcription factor (TF) families, not the canonical subset master regulators T-bet, GATA3 or RORγ. Helper T cell subsets are characterized functionally by the cytokines they produce. Benoist and colleagues demonstrate that in vivo helper T cells do not manifest as discrete helper subsets but rather form a continuum shaped by microbial exposure.
End‐of‐life priorities of older adults with terminal illness and caregivers: A qualitative consultation
Background As older adults approach the end‐of‐life (EOL), many are faced with complex decisions including whether to use medical advances to prolong life. Limited information exists on the priorities of older adults at the EOL. Objective This study aimed to explore patient and family experiences and identify factors deemed important to quality EOL care. Method A descriptive qualitative study involving three focus group discussions (n = 18) and six in‐depth interviews with older adults suffering from either a terminal condition and/or caregivers were conducted in NSW, Australia. Data were analysed thematically. Results Seven major themes were identified as follows: quality as a priority, sense of control, life on hold, need for health system support, being at home, talking about death and competent and caring health professionals. An underpinning priority throughout the seven themes was knowing and adhering to patient's wishes. Conclusion Our study highlights that to better adhere to EOL patient's wishes a reorganization of care needs is required. The readiness of the health system to cater for this expectation is questionable as real choices may not be available in acute hospital settings. With an ageing population, a reorganization of care which influences the way we manage terminal patients is required.
Pepinemab antibody blockade of SEMA4D in early Huntington’s disease: a randomized, placebo-controlled, phase 2 trial
SIGNAL is a multicenter, randomized, double-blind, placebo-controlled phase 2 study (no. NCT02481674) established to evaluate pepinemab, a semaphorin 4D (SEMA4D)-blocking antibody, for treatment of Huntington’s disease (HD). The trial enrolled a total of 265 HD gene expansion carriers with either early manifest (EM, n  = 179) or late prodromal (LP, n  = 86) HD, randomized (1:1) to receive 18 monthly infusions of pepinemab ( n  = 91 EM, 41 LP) or placebo ( n  = 88 EM, 45 LP). Pepinemab was generally well tolerated, with a relatively low frequency of serious treatment-emergent adverse events of 5% with pepinemab compared to 9% with placebo, including both EM and LP participants. Coprimary efficacy outcome measures consisted of assessments within the EM cohort of (1) a two-item HD cognitive assessment family comprising one-touch stockings of Cambridge (OTS) and paced tapping (PTAP) and (2) clinical global impression of change (CGIC). The differences between pepinemab and placebo in mean change (95% confidence interval) from baseline at month 17 for OTS were −1.98 (−4.00, 0.05) (one-sided P  = 0.028), and for PTAP 1.43 (−0.37, 3.23) (one-sided P  = 0.06). Similarly, because a significant treatment effect was not observed for CGIC, the coprimary endpoint, the study did not meet its prespecified primary outcomes. Nevertheless, a number of other positive outcomes and post hoc subgroup analyses—including additional cognitive measures and volumetric magnetic resonance imaging and fluorodeoxyglucose–positron-emission tomography imaging assessments—provide rationale and direction for the design of a phase 3 study and encourage the continued development of pepinemab in patients diagnosed with EM HD. The SIGNAL Phase 2 study of pepinemab immunotherapy in early Huntington’s disease (HD) did not meet its coprimary clinical efficacy endpoints, but had a favorable safety profile and showed a significant treatment-related reduction in caudate brain atrophy and reversal of the characteristic decline in brain metabolic activity that is typical of HD progression.
Height as a Clinical Biomarker of Disease Burden in Adult Mitochondrial Disease
Abstract Context Abnormal growth and short stature are observed in patients with mitochondrial disease, but it is unclear whether there is a relationship between final adult height and disease severity. Objective To determine whether patients with genetically confirmed mitochondrial disease are shorter than their peers and whether stature is related to disease severity. Design Analysis of final adult height in relation to disease severity as determined by the Newcastle Mitochondrial Disease Adult Scale (NMDAS). Setting UK Mitochondrial Disease Patient Cohort (Mito Cohort). Patients 575 patients were identified with recorded height, weight, and molecular genetic diagnosis of mitochondrial disease within the Mito Cohort. Main Outcome Measures Adult height, body mass index (BMI), and their association with genetic subgroup and disease severity. Results Adults with mitochondrial disease were short, with a mean height of −0.49 SD (95% CI, −0.58 to −0.39; n = 575) compared with UK reference data. Patients were overweight, with a BMI SD of 0.52 (95% CI, 0.37 to 0.67; n = 472). The most common genetic subgroup (m.3243A>G mutation) had a height SD of −0.70 (95% CI, −0.85 to −0.54; n = 234) and a BMI SD of 0.12 (95% CI, −0.10 to 0.34; n = 212). NMDAS scores were negatively correlated with height SD (r = −0.25; 95% CI, −0.33 to −0.17; P < 0.001, n = 533). Rate of disease progression also correlated negatively with adult height (P < 0.001). Conclusion Final height in mitochondrial disease reflects disease severity and rate of disease progression. Mitochondrial dysfunction and associated subclinical comorbidities affect growth plate physiology. Patients with mitochondrial disease are shorter than the general population, with adult height related to disease severity and rate of disease progression.
Testosterone and sexual risk among transmen: a mixed methods exploratory study
Little research has explored the link between the behavioural effects of testosterone use among transmen and HIV risk. We conducted a mixed methods study to explore testosterone use among transmen and the behavioural effects on HIV risk. A sample of 122 transmen from San Francisco participated in a cross-sectional quantitative survey and 14 transmen participated in 2 focus group discussions. Most participants (81.9%) were currently taking hormones. Participants attributed testosterone use to new sexual behaviours among 69% of transmen, changes in sexual attraction (49%), and increased frequency of sexual activity (72%). Among current testosterone users, 3.3% had cisgender men as partners before starting testosterone, whereas after starting testosterone, 25.4% did. Similarly, 4.1% had a transgender woman as a sexual partner before starting testosterone and 13.9% after starting testosterone. Findings suggest that testosterone's side effects were associated with transmen's desires for sex with cisgender men who have sex with men. The reported increase in attraction to and sex with partners from populations with a high HIV prevalence may have important implications for HIV risk among transmen, especially as the availability of transgender health services may draw transmen to a context in which HIV prevalence is high.
Cognitive deficits in adult m.3243A>G‐ and m.8344A>G‐related mitochondrial disease: importance of correcting for baseline intellectual ability
Objective To determine the cognitive profile of adult patients with mitochondrial disease, and the effect of disease severity on cognition. Methods Using a prospective case‐control design, we compared cognition of patients to normative data and to matched controls, assessed three times over 18 months. Forty‐nine patients with m.3243A>G (N = 36) and m.8344A>G (N = 13) mtDNA mutations and 32 controls, matched by age (±5 years) and premorbid cognition (±10 WTAR FSIQ points), participated. Participants completed neuropsychological assessments of general cognition (WAIS‐IV), executive function (D‐KEFS), and memory (WMS‐IV). Potential predictors of cognition were explored. Results Patients show mild‐to‐moderate premorbid cognitive impairment, but substantial impairment in current general cognition and distinct domains, including verbal comprehension, perceptual reasoning, working memory, processing speed, and memory retrieval. Executive dysfunction may be caused by slower decision‐making. Patients performed worse than controls, except on memory tasks, indicating intact memory, when premorbid cognition is controlled for. Premorbid cognition and disease severity were consistent predictors of cognition in patients; however, cognitive decline appears slow and is unlikely in the short‐term, when other disease‐specific factors remain stable. Interpretation Patients should be monitored to facilitate early identification of a complex profile of cognitive deficits and individuals with higher disease burden should be followed up more closely. On development of cognitive difficulties, appropriate compensatory strategies should be determined through in‐depth assessment. Using strategies such as slower presentation of information, multiple modes of presentation, active discussion to aid understanding and decision‐making, and use of memory aids, may ameliorate difficulties.