Beneficial effect of human anti-amyloid-β active immunization on neurite morphology and tau pathology

Anti-amyloid-β immunization leads to amyloid clearance in patients with Alzheimer's disease, but the effect of vaccination on amyloid-β-induced neuronal pathology has not been quantitatively examined. The objectives of this study were to address the effects of anti-amyloid-β active immunization on neurite trajectories and the pathological hallmarks of Alzheimer's disease in the human hippocampus. Hippocampal sections from five patients with Alzheimer's disease enrolled in the AN1792 Phase 2a trial were compared with those from 13 non-immunized Braak-stage and age-matched patients with Alzheimer's disease, and eight age-matched non-demented controls. Analyses included neurite curvature ratio as a quantitative measure of neuritic abnormalities, amyloid and tau loads, and a quantitative characterization of plaque-associated neuritic dystrophy and astrocytosis. Amyloid load and density of dense-core plaques were decreased in the immunized group compared to non-immunized patients (P < 0.01 and P < 0.001, respectively). The curvature ratio in non-immunized patients with Alzheimer's disease was elevated compared to non-demented controls (P < 0.0001). In immunized patients, however, the curvature ratio was normalized when compared to non-immunized patients (P < 0.0001), and not different from non-demented controls. In the non-immunized patients, neurites close to dense-core plaques (within 50 µm) were more abnormal than those far from plaques (i.e. beyond 50 µm) (P < 0.0001). By contrast, in the immunized group neurites close to and far from the remaining dense-core plaques did not differ, and both were straighter compared to the non-immunized patients (P < 0.0001). Compared to non-immunized patients, dense-core plaques remaining after immunization had similar degree of astrocytosis (P = 0.6060), more embedded dystrophic neurites (P < 0.0001) and were more likely to have mitochondrial accumulation (P < 0.001). In addition, there was a significant decrease in the density of paired helical filament-1-positive neurons in the immunized group as compared to the non-immunized (P < 0.05), but not in the density of Alz50 or thioflavin-S positive tangles, suggesting a modest effect of anti-amyloid-β immunization on tangle pathology. Clearance of amyloid plaques upon immunization with AN1792 effectively improves a morphological measure of neurite abnormality in the hippocampus. This improvement is not just attributable to the decrease in plaque load, but also occurs within the halo of the remaining dense-core plaques. However, these remaining plaques still retain some of their toxic potential. Anti-amyloid-β immunization might also ameliorate the hippocampal tau pathology through a decrease in tau phosphorylation. These data agree with preclinical animal studies and further demonstrate that human anti-amyloid-β immunization does not merely clear amyloid from the Alzheimer's disease brain, but reduces some of the neuronal alterations that characterize Alzheimer's diseas

Estimated Glomerular Filtration Rate, Albuminuria, and Adverse Outcomes. An Individual-Participant Data Meta-Analysis

IMPORTANCE: Chronic kidney disease (low estimated glomerular filtration rate [eGFR] or albuminuria) affects approximately 14% of adults in the US. OBJECTIVE: To evaluate associations of lower eGFR based on creatinine alone, lower eGFR based on creatinine combined with cystatin C, and more severe albuminuria with adverse kidney outcomes, cardiovascular outcomes, and other health outcomes. DESIGN, SETTING, AND PARTICIPANTS: Individual-participant data meta-analysis of 27 503 140 individuals from 114 global cohorts (eGFR based on creatinine alone) and 720 736 individuals from 20 cohorts (eGFR based on creatinine and cystatin C) and 9 067 753 individuals from 114 cohorts (albuminuria) from 1980 to 2021. EXPOSURES: The Chronic Kidney Disease Epidemiology Collaboration 2021 equations for eGFR based on creatinine alone and eGFR based on creatinine and cystatin C; and albuminuria estimated as urine albumin to creatinine ratio (UACR). MAIN OUTCOMES AND MEASURES: The risk of kidney failure requiring replacement therapy, all-cause mortality, cardiovascular mortality, acute kidney injury, any hospitalization, coronary heart disease, stroke, heart failure, atrial fibrillation, and peripheral artery disease. The analyses were performed within each cohort and summarized with random-effects meta-analyses. RESULTS: Within the population using eGFR based on creatinine alone (mean age, 54 years [SD, 17 years]; 51% were women; mean follow-up time, 4.8 years [SD, 3.3 years]), the mean eGFR was 90 mL/min/1.73 m2 (SD, 22 mL/min/1.73 m2) and the median UACR was 11 mg/g (IQR, 8-16 mg/g). Within the population using eGFR based on creatinine and cystatin C (mean age, 59 years [SD, 12 years]; 53% were women; mean follow-up time, 10.8 years [SD, 4.1 years]), the mean eGFR was 88 mL/min/1.73 m2 (SD, 22 mL/min/1.73 m2) and the median UACR was 9 mg/g (IQR, 6-18 mg/g). Lower eGFR (whether based on creatinine alone or based on creatinine and cystatin C) and higher UACR were each significantly associated with higher risk for each of the 10 adverse outcomes, including those in the mildest categories of chronic kidney disease. For example, among people with a UACR less than 10 mg/g, an eGFR of 45 to 59 mL/min/1.73 m2 based on creatinine alone was associated with significantly higher hospitalization rates compared with an eGFR of 90 to 104 mL/min/1.73 m2 (adjusted hazard ratio, 1.3 [95% CI, 1.2-1.3]; 161 vs 79 events per 1000 person-years; excess absolute risk, 22 events per 1000 person-years [95% CI, 19-25 events per 1000 person-years]). CONCLUSIONS AND RELEVANCE: In this retrospective analysis of 114 cohorts, lower eGFR based on creatinine alone, lower eGFR based on creatinine and cystatin C, and more severe UACR were each associated with increased rates of 10 adverse outcomes, including adverse kidney outcomes, cardiovascular diseases, and hospitalizations

Factors associated with COVID-19 vaccine uptake in people with kidney disease: an OpenSAFELY cohort study.

OBJECTIVE: To characterise factors associated with COVID-19 vaccine uptake among people with kidney disease in England. DESIGN: Retrospective cohort study using the OpenSAFELY-TPP platform, performed with the approval of NHS England. SETTING: Individual-level routine clinical data from 24 million people across GPs in England using TPP software. Primary care data were linked directly with COVID-19 vaccine records up to 31 August 2022 and with renal replacement therapy (RRT) status via the UK Renal Registry (UKRR). PARTICIPANTS: A cohort of adults with stage 3-5 chronic kidney disease (CKD) or receiving RRT at the start of the COVID-19 vaccine roll-out was identified based on evidence of reduced estimated glomerular filtration rate (eGFR) or inclusion in the UKRR. MAIN OUTCOME MEASURES: Dose-specific vaccine coverage over time was determined from 1 December 2020 to 31 August 2022. Individual-level factors associated with receipt of a 3-dose or 4-dose vaccine series were explored via Cox proportional hazards models. RESULTS: 992 205 people with stage 3-5 CKD or receiving RRT were included. Cumulative vaccine coverage as of 31 August 2022 was 97.5%, 97.0% and 93.9% for doses 1, 2 and 3, respectively, and 81.9% for dose 4 among individuals with one or more indications for eligibility. Delayed 3-dose vaccine uptake was associated with younger age, minority ethnicity, social deprivation and severe mental illness-associations that were consistent across CKD severity subgroups, dialysis patients and kidney transplant recipients. Similar associations were observed for 4-dose uptake. CONCLUSION: Although high primary vaccine and booster dose coverage has been achieved among people with kidney disease in England, key disparities in vaccine uptake remain across clinical and demographic groups and 4-dose coverage is suboptimal. Targeted interventions are needed to identify barriers to vaccine uptake among under-vaccinated subgroups identified in the present study

Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure.

Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we identified at genome-wide significance (P = 2.7 × 10(-8) to P = 2.3 × 10(-13)) four new PP loci (at 4q12 near CHIC2, 7q22.3 near PIK3CG, 8q24.12 in NOV and 11q24.3 near ADAMTS8), two new MAP loci (3p21.31 in MAP4 and 10q25.3 near ADRB1) and one locus associated with both of these traits (2q24.3 near FIGN) that has also recently been associated with SBP in east Asians. For three of the new PP loci, the estimated effect for SBP was opposite of that for DBP, in contrast to the majority of common SBP- and DBP-associated variants, which show concordant effects on both traits. These findings suggest new genetic pathways underlying blood pressure variation, some of which may differentially influence SBP and DBP

Rates of serious clinical outcomes in survivors of hospitalisation with COVID-19: a descriptive cohort study within the OpenSAFELY platform

AbstractBackgroundPatients with COVID-19 are thought to be at higher risk of cardiometabolic and pulmonary complications, but quantification of that risk is limited. We aimed to describe the overall burden of these complications in survivors of severe COVID-19.MethodsWorking on behalf of NHS England, we used linked primary care records, death certificate and hospital data from the OpenSAFELY platform. We constructed three cohorts: patients discharged following hospitalisation with COVID-19, patients discharged following hospitalisation with pneumonia in 2019, and a frequency-matched cohort from the general population in 2019. We studied eight cardiometabolic and pulmonary outcomes. Absolute rates were measured in each cohort and Cox regression models were fitted to estimate age/sex adjusted hazard ratios comparing outcome rates between discharged COVID-19 patients and the two comparator cohorts.ResultsAmongst the population of 31,716 patients discharged following hospitalisation with COVID-19, rates for majority of outcomes peaked in the first month post-discharge, then declined over the following four months. Patients in the COVID-19 population had markedly increased risk of all outcomes compared to matched controls from the 2019 general population, especially for pulmonary embolism (HR 12.86; 95% CI: 11.23 - 14.74). Outcome rates were more similar when comparing patients discharged with COVID-19 to those discharged with pneumonia in 2019, although COVID-19 patients had increased risk of type 2 diabetes (HR 1.23; 95% CI: 1.05 - 1.44).InterpretationCardiometabolic and pulmonary adverse outcomes are markedly raised following hospitalisation for COVID-19 compared to the general population. However, the excess risks were more comparable to those seen following hospitalisation with pneumonia. Identifying patients at particularly high risk of outcomes would inform targeted preventive measures.FundingWellcome, Royal Society, National Institute for Health Research, National Institute for Health Research Oxford Biomedical Research Centre, UK Medical Research Council, UK Research and Innovation, Health and Safety Executive.</jats:sec

An Automated Image Processing and Classification Scheme for Identifying Cancerous Soft-Shell Clam Hemocytes in Unstained Bright-Field Photomicrographs

Disseminated neoplasia is a type of cancer that is prevalent in marine bivalves. A group of biologists at the University of New Hampshire are frequently tasked with estimating the proliferation of this cancer in soft-shell clam hemocytes using unstained samples and a bright-field microscope without the use of any real means of quantization. Instead, their measurement is a purely visual analysis of confluency where varying individual experience amongst researchers, no usage of stains, cell clustering and the general nature of the microscopy environment make it exceedingly difficult to perform this task with consistent accuracy. This thesis details the application of image processing and machine learning to streamline this process in an effort to reduce human error and provide researchers with more reliable identification of cancerous hemocytes from photomicrographs. This work contains analysis of noise in input images, its sources and the preprocessing methods used for mitigation. A segmentation algorithm capable of isolating individual cells from each image is also explained. This is followed by an assessment of structural, morphometric and densiometric features extracted from regions of interest. Finally, discussion of the applicability of these feature vectors to train various classifier models is presented. The training dataset used for this work was extremely skewed due to an over abundance of healthy cells relative to cancerous ones leading to additional consideration of a secondary dataset modified to alleviate skew. The differences between the most successful classification methods are described for both datasets, including their success in locating new cells not included in the training data. While not entirely free of errors (~95\% theoretical accuracy), this algorithm successfully provides researchers with an improved means for identifying cancerous hemocytes

Quantifying and Adjusting for Confounding From Health-Seeking Behavior and Health Care Access in Observational Research.

BACKGROUND: Health-seeking behavior and health care access (HSB/HCA) are recognized confounders in many observational studies but are not directly measurable in electronic health records. We used proxy markers of HSB/HCA to quantify and adjust for confounding in observational studies of influenza and COVID-19 vaccine effectiveness (VE). METHODS: This cohort study used primary care data prelinked to secondary care and death data in England. We included individuals aged ≥66 years on 1 September 2019 and assessed influenza VE in the 2019-2020 season and early COVID-19 VE (December 2020-March 2021). VE was estimated with sequential adjustment for demographics, comorbidities, and 14 markers of HSB/HCA. Influenza vaccination in the 2019-2020 season was also considered a negative control exposure against COVID-19 before COVID-19 vaccine rollout. RESULTS: We included 1 991 284, 1 796 667, and 1 946 943 individuals in the influenza, COVID-19, and negative control exposure populations, respectively. Markers of HSB/HCA were positively correlated with influenza and COVID-19 vaccine uptake. For influenza, adjusting for HSB/HCA markers in addition to demographics and comorbidities increased VE against influenza-like illness from -1.5% (95% CI, -3.2% to .1%) to 7.1% (95% CI, 5.4%-8.7%) with a less apparent trend for more severe outcomes. For COVID-19, adjusting for HSB/HCA markers did not change VE estimates against infection or severe disease (eg, 2 doses of BNT162b2 against infection: 82.8% [95% CI, 78.4%-86.3%] to 83.1% [95% CI, 78.7%-86.5%]). Adjusting for HSB/HCA markers removed bias in the negative control exposure analysis (-7.5% [95% CI, -10.6% to -4.5%] vs -2.1% [95% CI, -6.0% to 1.7%] before vs after adjusting for HSB/HCA markers). CONCLUSIONS: Markers of HSB/HCA can be used to quantify and account for confounding in observational vaccine studies

Centre variation in mortality following post-hospitalisation acute kidney injury: Analysis of a large national cohort.

BACKGROUND Routine monitoring of outcomes for patients with Acute Kidney Injury (AKI) is important to drive ongoing quality improvement in patient care. In this study, we describe development of a case-mix adjusted 30-day mortality indicator for patients with post-hospitalisation AKI (H-AKI) across England, to facilitate identification of any unwarranted centre-variation in outcomes. METHODS We utilised a routinely collected national dataset of biochemically detected AKI cases, linked with national hospitals administrative and mortality data. 250,504 H-AKI episodes were studied in total, across 103 NHS hospital trusts, between January 2017 - December 2018. Standardised mortality ratios (SMRs) were calculated for each trust using logistic regression; adjusting for age, sex, primary diagnosis, comorbidity score, AKI severity, month of AKI, and admission method. RESULTS Mean 30-day mortality rate was high at 28.6%. SMRs for 23/103 trusts were classed as outliers, 12 above and 11 below the 95% control limits. Patients with H-AKI had mortality rates over 5 times higher than the overall hospitalised population in 90/136 diagnosis groups and over 10 times higher in 60/136 groups. Presentation at trusts with a co-located specialist nephrology service was associated with a lower mortality risk, as was South Asian or Black ethnicity. Deprivation, however, was associated with higher mortality. CONCLUSIONS This is the largest multi-centre analysis of mortality for patients with biochemically ascertained H-AKI to date, demonstrating once again the considerable risk associated with developing even mild elevations in serum creatinine. Mortality rates varied considerably across centres and those identified as outliers will now need to carefully interrogate local care pathways to understand and address reasons for this, with national policy required to tackle the identified health disparities