Genome sequence analyses identify novel risk loci for multiple system atrophy.

Multiple system atrophy (MSA) is an adult-onset, sporadic synucleinopathy characterized by parkinsonism, cerebellar ataxia, and dysautonomia. The genetic architecture of MSA is poorly understood, and treatments are limited to supportive measures. Here, we performed a comprehensive analysis of whole genome sequence data from 888 European-ancestry MSA cases and 7,128 controls to systematically investigate the genetic underpinnings of this understudied neurodegenerative disease. We identified four significantly associated risk loci using a genome-wide association study approach. Transcriptome-wide association analyses prioritized USP38-DT, KCTD7, and lnc-KCTD7-2 as novel susceptibility genes for MSA within these loci, and single-nucleus RNA sequence analysis found that the associated variants acted as cis-expression quantitative trait loci for multiple genes across neuronal and glial cell types. In conclusion, this study highlights the role of genetic determinants in the pathogenesis of MSA, and the publicly available data from this study represent a valuable resource for investigating synucleinopathies.

Neutralization of SARS-CoV-2 Omicron BQ.1, BQ.1.1 and XBB.1 variants following SARS-CoV-2 infection or vaccination in children.

Emergence of highly transmissible Omicron subvariants led to increased SARS-CoV-2 infection and disease in children. However, minimal knowledge exists regarding the neutralization capacity against circulating Omicron BA.4/BA.5, BA.2.75, BQ.1, BQ.1.1 and XBB.1 subvariants following SARS-CoV-2 vaccination in children versus during acute or convalescent COVID-19, or versus multisystem inflammatory syndrome (MIS-C). Here, we evaluate virus-neutralizing capacity against SARS-CoV-2 variants in 151 age-stratified children ( <5, 5-11, 12-21 years old) hospitalized with acute severe COVID-19 or MIS-C or convalescent mild (outpatient) infection compared with 62 age-stratified vaccinated children. An age-associated effect on neutralizing antibodies is observed against SARS-CoV-2 following acute COVID-19 or vaccination. The primary series BNT162b2 mRNA vaccinated adolescents show higher vaccine-homologous WA-1 neutralizing titers compared with <12 years vaccinated children. Post-infection antibodies did not neutralize BQ.1, BQ.1.1 and XBB.1 subvariants. In contrast, monovalent mRNA vaccination induces more cross-neutralizing antibodies in young children <5 years against BQ.1, BQ.1.1 and XBB.1 variants compared with ≥5 years old children. Our study demonstrates that in children, infection and monovalent vaccination-induced neutralization activity is low against BQ.1, BQ.1.1 and XBB.1 variants. These findings suggest a need for improved SARS-CoV-2 vaccines to induce durable, more cross-reactive neutralizing antibodies to provide effective protection against emerging variants in children.

Association Between Intestinal Microbiota Collected at Hospital Admission and Outcomes of Patients With Cirrhosis.

BACKGROUND & AIMS: Inpatients with cirrhosis are prone to develop acute-on-chronic liver failure (ACLF). ACLF is associated with dysbiosis of the intestinal microbiota, which might serve as a prognostic factor. We investigated whether features of the intestinal microbiota associate organ failure, transfer to intensive care, and mortality within 30 days in patients admitted to the hospital with cirrhosis. METHODS: Stool samples were collected from 181 patients with cirrhosis (age 56 years; mean model for end-stage liver disease score, 21; 43% with infections) at time of admission, from multiple hospitals in North America. Patients were followed for 30 days for development of ACLF, extra-hepatic organ failures, and death or hospice care. Microbiota were analyzed by 16s rRNA sequencing for alpha diversity (within groups), beta diversity (between groups), cirrhosis dysbiosis ratio (CDR), and taxa that differed between groups with vs without negative outcomes (individual organ failures, transfer to intensive care, ACLF, death, or hospice). Regression analyses were performed using microbial and clinical variables for each outcome. RESULTS: ACLF developed in 8% of study subjects; 16% were transferred to intensive care and 21% died. Beta diversity of the intestinal microbiome was significantly different, whereas alpha diversity was similar, between subjects with vs without outcomes. The CDR was lower in subjects who developed ACLF, especially among those with renal failure. Taxa belonging to phylum Proteobacteria (Enterobacteriaceae, Campylobacteriaceae, and Pasteurellaceae) and Firmicutes (Enterococcaceae and Streptococcaceae) were associated with development of negative outcomes, whereas other Firmicutes members (Lachnospiraceae and Clostridiales) reduced risk of negative outcomes. Changes in the microbiota associated with extra-hepatic organ failure, transfer to intensive care, ACLF, and death, independently on logistic regression analyses. CONCLUSION: In hospitalized patients with cirrhosis, dysbiosis of the intestinal microbiota on admission (particularly changes in Protebacteria constituents) associates with increased risk of extra-hepatic organ failure, ACLF, and death, independent of clinical factors. Strategies to reduce gut dysbiosis might improve outcomes of patients with cirrhosis.

Overlap of the cancer genome atlas and the immune epitope database.

Mutant peptides resulting from cancer drivers or passenger mutations are expected to have the potential to serve as a basis for cancer vaccines. However, a number of parameters regulate vaccine-associated immunogenicity, including the suitability of a peptide for binding to an antigen-presenting molecule or antibody. In order to obtain a basic indication of the prospect of human cancer epitope identification via current database development strategies, an overlap of the mutant Homo sapiens epitopes listed on the Immune Epitope Database (IEDB) and the mutant peptides indicated by The Cancer Genome Atlas (TCGA) somatic mutation database was obtained. No putative TCGA mutant peptides were detected among the 8,890 14-18 amino acid (AA) IEDB peptides available. In total, 3 IEDB mutant epitopes that encompassed a TCGA mutant AA position, but did not overlap the exact position of the TCGA mutant AA, were detected. The results of the present analysis confirm that verification of certain aspects of cancer epitope function can be obtained via the continued and systematic expansion of databases representing human protein epitopes. However, the analysis also indicates that there is relatively limited systematic information available regarding antigen-presenting molecule epitopes and cancer-related mutant peptides.