JAMA neurology最新文献

Importance: The X chromosome has remained enigmatic in Alzheimer disease (AD), yet it makes up 5% of the genome and carries a high proportion of genes expressed in the brain, making it particularly appealing as a potential source of unexplored genetic variation in AD.

Objectives: To perform the first large-scale X chromosome-wide association study (XWAS) of AD.

Design, setting, and participants: This was a meta-analysis of genetic association studies in case-control, family-based, population-based, and longitudinal AD-related cohorts from the US Alzheimer's Disease Genetics Consortium, the Alzheimer's Disease Sequencing Project, the UK Biobank, the Finnish health registry, and the US Million Veterans Program. Risk of AD was evaluated through case-control logistic regression analyses. Data were analyzed between January 2023 and March 2024. Genetic data available from high-density single-nucleotide variant microarrays and whole-genome sequencing and summary statistics for multitissue expression and protein quantitative trait loci available from published studies were included, enabling follow-up genetic colocalization analyses. A total of 1 629 863 eligible participants were selected from referred and volunteer samples, 477 596 of whom were excluded for analysis exclusion criteria. The number of participants who declined to participate in original studies was not available.

Main outcome and measures: Risk of AD, reported as odds ratios (ORs) with 95% CIs. Associations were considered at X chromosome-wide (P < 1 × 10-5) and genome-wide (P < 5 × 10-8) significance. Primary analyses are nonstratified, while secondary analyses evaluate sex-stratified effects.

Results: Analyses included 1 152 284 participants of non-Hispanic White, European ancestry (664 403 [57.7%] female and 487 881 [42.3%] male), including 138 558 individuals with AD. Six independent genetic loci passed X chromosome-wide significance, with 4 showing support for links between the genetic signal for AD and expression of nearby genes in brain and nonbrain tissues. One of these 4 loci passed conservative genome-wide significance, with its lead variant centered on an intron of SLC9A7 (OR, 1.03; 95% CI, 1.02-1.04) and colocalization analyses prioritizing both the SLC9A7 and nearby CHST7 genes. Of these 6 loci, 4 displayed evidence for escape from X chromosome inactivation with regard to AD risk.

Conclusion and relevance: This large-scale XWAS of AD identified the novel SLC9A7 locus. SLC9A7 regulates pH homeostasis in Golgi secretory compartments and is anticipated to have downstream effects on amyloid β accumulation. Overall, this study advances our knowledge of AD genetics and may provide novel biological drug targets. The results further provide initial insights into elucidating the role of the X chromosome in sex-based differences in AD.

Importance: Approximately 10% to 15% of ischemic strokes are associated with cancer; cancer-associated stroke, particularly when cryptogenic, is associated with high rates of recurrent stroke and major bleeding. Limited data exist on the safety and efficacy of different antithrombotic strategies in patients with cancer and cryptogenic stroke.

Objective: To compare apixaban vs aspirin for the prevention of adverse clinical outcomes in patients with history of cancer and cryptogenic stroke.

Design, setting, and participants: Post hoc analysis of data from 1015 patients with a recent cryptogenic stroke and biomarker evidence of atrial cardiopathy in the Atrial Cardiopathy and Antithrombotic Drugs in Prevention After Cryptogenic Stroke (ARCADIA) trial, a multicenter, randomized, double-blind clinical trial conducted from 2018 to 2023 at 185 stroke centers in North America. Data analysis was performed from October 15, 2023, to May 23, 2024.

Exposures: Oral apixaban, 5 mg (or 2.5 mg if criteria met), twice daily vs oral aspirin, 81 mg, once daily. Subgroups of patients with and without cancer at baseline were examined.

Main outcomes and measures: The primary outcome for this post hoc analysis was a composite of major ischemic or major hemorrhagic events. Major ischemic events were recurrent ischemic stroke, myocardial infarction, systemic embolism, and symptomatic deep vein thrombosis or pulmonary embolism. Major hemorrhagic events included symptomatic intracranial hemorrhage and any major extracranial hemorrhage.

Results: Among 1015 participants (median [IQR] age, 68 [60-76] years; 551 [54.3%] female), 137 (13.5%) had a history of cancer. The median (IQR) follow-up was 1.5 (0.6-2.5) years for patients with history of cancer and 1.5 (0.6-3.0) years for those without history of cancer. Participants with history of cancer, compared with those without history of cancer, had a higher risk of major ischemic or major hemorrhagic events (hazard ratio [HR], 1.73; 95% CI, 1.10-2.71). Among those with history of cancer, 8 of 61 participants (13.1%) randomized to apixaban and 16 of 76 participants (21.1%) randomized to aspirin had a major ischemic or major hemorrhagic event; however, the risk was not significantly different between groups (HR, 0.61; 95% CI, 0.26-1.43). Comparing participants randomized to apixaban vs aspirin among those with cancer, events included recurrent stroke (5 [8.2%] vs 9 [11.8%]), major ischemic events (7 [11.5%] vs 14 [18.4%]), and major hemorrhagic events (1 [1.6%] vs 2 [2.6%]).

Conclusions and relevance: Among participants in the ARCADIA trial with history of cancer, the risk of major ischemic and hemorrhagic events did not differ significantly with apixaban compared with aspirin.

Trial registration: ClinicalTrials.gov Identifier: NCT03192215.