Discretion in decision to receive COVID-19 vaccines and associated socio-economic inequalities in rates of uptake: a whole-of-population data linkage study from Australia

OBJECTIVE

In Australia, first and second compared to third dose of a COVID-19 vaccine were implemented under different policies and contexts, resulting in greater discretion in decisions to receive a third compared to first and second dose. We quantified socio-economic inequalities in first and third dose to understand how discretion is associated with differences in uptake.

STUDY DESIGN

Whole-of-population cohort study.

METHODS

Linked immunisation, census, death and migration data were used to estimate weekly proportions who received first and third doses of a COVID-19 vaccine until 31 August 2022 for those with low (no formal qualification) compared to high (university degree) education, stratified by 10-year age group (from 30 to 89 years). We estimated relative rates using Cox regression, including adjustment for sociodemographic factors.

RESULTS

Among 13.1 million people in our study population, 94% had received a first and 80% a third dose by 31 August 2022. Rates of uptake of first and third dose were around 50% lower for people with low compared to high education. Gaps were small in absolute terms for first dose, and at the end of the study period ranged from 1 to 11 percentage points across age groups. However, gaps were substantial for third dose, particularly at younger ages where the socio-economic gap was as wide as 32 percentage-points.

CONCLUSION

Education-related inequalities in uptake were larger where discretion in decisions was larger. Policies that limited discretion in decisions to receive vaccines may have contributed to achieving the dual aims of maximising uptake and minimising inequalities.

Optimizing and developing a scalable, chemically defined, animal component-free lentiviral vector production process in a fixed-bed bioreactor

Lentiviral vectors (LVVs) play a critical role in gene delivery for ex vivo gene-modified cell therapies. However, the lack of scalable LVV production methods and the high cost associated with them may limit their use. In this work, we demonstrate the optimization and development of a scalable, chemically defined, animal component-free LVV production process using adherent human embryonic kidney 293T cells in a fixed-bed bioreactor. The initial studies focused on the optimization of the culture process in 2D static cultures. Process changes such as decreasing cell seeding density on day 0 from 2.5 × 10⁴ to 5 × 10³ cells/cm², delaying the transient transfection from 24 to 120 h post-seeding, reducing plasmid DNA to 167 ng/cm², and adding 5 mM sodium butyrate 6 h post-transfection improved functional LVV titers by 26.9-fold. The optimized animal component-free production process was then transferred to the iCELLis Nano bioreactor, a fixed-bed bioreactor, where titers of 1.2 × 10⁶ TU/cm² were achieved when it was operated in perfusion. In this work, comparable functional LVV titers were obtained with FreeStyle 293 Expression medium and the conventional Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum both at small and large scale.

Cationic polymer precipitation for enhanced impurity removal in downstream processing

Precipitation can be used for the removal of impurities early in the downstream purification process of biologics, with the soluble product remaining in the filtrate through microfiltration. The objective of this study was to examine the use of polyallylamine (PAA) precipitation to increase the purity of product via higher host cell protein removal to enhance polysorbate excipient stability to enable a longer shelf life. Experiments were performed using three monoclonal antibodies (mAbs) with different properties of isoelectric point and IgG subclass. High throughput workflows were established to quickly screen precipitation conditions as a function of pH, conductivity and PAA concentrations. Process analytical tools (PATs) were used to evaluate the size distribution of particles and inform the optimal precipitation condition. Minimal pressure increase was observed during depth filtration of the precipitates. The precipitation was scaled up to 20L size and the extensive characterization of precipitated samples after protein A chromatography showed >75% reduction of host cell protein (HCP) concentrations (by ELISA), >90% reduction of number of HCP species (by mass spectrometry), and >99.8% reduction of DNA. The stability of polysorbate containing formulation buffers for all three mAbs in the protein A purified intermediates was improved at least 25% after PAA precipitation. Mass spectrometry was used to obtain additional understanding of the interaction between PAA and HCPs with different properties. Minimal impact on product quality and <5% yield loss after precipitation were observed while the residual PAA was <9 ppm. These results expand the toolbox in downstream purification to solve HCP clearance issues for programs with purification challenges, while also providing important insights into the integration of precipitation-depth filtration and the current platform process for the purification of biologics.

A High‐Throughput Approach to Developing and Optimizing Mixed‐Mode Membrane Chromatography for Protein Purification

Membrane chromatography has been established as a viable alternative to packed-bed column chromatography for the purification of therapeutic proteins. Purification via membrane chromatography offers key advantages, including higher productivity and reduced buffer usage. Unlike column chromatography purification, the utilization of high-throughput screening in order to reduce development times and material requirements has been a challenge for membrane chromatography. This research focused on the development of a new, high-throughput screening technique for use in screening membrane chromatography conditions for monoclonal antibody purification. The developed screen utilizes a 96-well plate format, thereby allowing for the screening of multiple different membrane conditions at once. For this study, four mixed-mode cation exchange membranes and one cation exchange membrane were evaluated on the plate. The screen is performed in a similar manner to that of a resin slurry plate screen, however, instead of a single loading step, the antibody feed was loaded in 50 mg/ml increments up to a maximum loading of 450 mg/ml. Performing a similar, incremental loading on a resin plate would be impractical, as mixing times are substantially longer due to pore diffusion limitations. However, due to the significantly faster rate of mass transfer for membranes relative to resin, mixing times could be reduced by up to a factor of sixty on the membrane plate. Additional optimization showed that higher hydrophobicity can potentially lead to slower kinetics and mixing times that may need to be adjusted accordingly. The end result is a screen that has been proven to provide results comparable to those obtained on larger-scale membrane purification runs while also enabling exploration of a much greater operating space and significantly reducing the feed materials required.

Inequalities in life expectancy in Australia according to education level: a whole-of-population record linkage study

Background

Life expectancy in Australia is amongst the highest globally, but national estimates mask within-country inequalities. To monitor socioeconomic inequalities in health, many high-income countries routinely report life expectancy by education level. However in Australia, education-related gaps in life expectancy are not routinely reported because, until recently, the data required to produce these estimates have not been available. Using newly linked, whole-of-population data, we estimated education-related inequalities in adult life expectancy in Australia.

Methods

Using data from 2016 Australian Census linked to 2016-17 Death Registrations, we estimated age-sex-education-specific mortality rates and used standard life table methodology to calculate life expectancy. For men and women separately, we estimated absolute (in years) and relative (ratios) differences in life expectancy at ages 25, 45, 65 and 85 years according to education level (measured in five categories, from university qualification [highest] to no formal qualifications [lowest]).

Results

Data came from 14,565,910 Australian residents aged 25 years and older. At each age, those with lower levels of education had lower life expectancies. For men, the gap (highest vs. lowest level of education) was 9.1 (95 %CI: 8.8, 9.4) years at age 25, 7.3 (7.1, 7.5) years at age 45, 4.9 (4.7, 5.1) years at age 65 and 1.9 (1.8, 2.1) years at age 85. For women, the gap was 5.5 (5.1, 5.9) years at age 25, 4.7 (4.4, 5.0) years at age 45, 3.3 (3.1, 3.5) years at 65 and 1.6 (1.4, 1.8) years at age 85. Relative differences (comparing highest education level with each of the other levels) were larger for men than women and increased with age, but overall, revealed a 10–25 % reduction in life expectancy for those with the lowest compared to the highest education level.

Conclusions

Education-related inequalities in life expectancy from age 25 years in Australia are substantial, particularly for men. Those with the lowest education level have a life expectancy equivalent to the national average 15–20 years ago. These vast gaps indicate large potential for further gains in life expectancy at the national level and continuing opportunities to improve health equity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12939-021-01513-3.

Association between attendance at an American diabetes camp and improvements in glycaemic control and treatment satisfaction

Introduction

Few studies have evaluated glycaemic control using continuous glucose monitoring (CGM) in individuals before and after attendance at a diabetes camp or by comparing control groups at home to control groups at camp.

Methods

Youth (6–17 years) with T1D and receiving insulin therapy were enrolled at a week‐long diabetes camp. They participated in three clinic visits: at the start of a week at home, by initiating a Dexcom G6 CGM system; at the start of a week at camp, where the home week G6 was removed and a camp week G6 was inserted; and after camp, where the camp week G6 was removed. We administered Problem Areas in Diabetes (PAID) surveys at the second and third visits. Participants with <80% CGM data coverage or who did not complete all PAID surveys were excluded from analysis. We compared glycaemic control and PAID scores between the week at home and week at camp.

Results

Of 76 enrolled campers, 69 completed the study and 52 had results that qualified for analysis. The mean participant age was 12.5 ± 2.2 years. Camp was associated with significantly improved treatment satisfaction, time in desired glucose range and insulin sensitivity. Time in hyperglycaemia and basal insulin requirements decreased significantly.

Conclusions

Diabetes camp is associated with significant improvements in diabetes treatment satisfaction and glycaemic control compared to home care.

Should Target Glucose Values Be Increased to Avoid Severe Hypoglycemia? Real-World Data Say “No.”

Early studies such as the Diabetes Control and Complications Trial showed a strong inverse relationship between A1C and the risk of severe hypoglycemia in type 1 diabetes. This risk has historically limited insulin therapy intensification efforts, and some treatment guidelines (e.g., Rosenzweig et al., J Clin Endocrinol Metab 105:969, 2020) suggest that A1C values &lt;7% confer an increased risk of hypoglycemia. Nowadays, real-time continuous glucose monitoring (CGM) systems can flatten and attenuate the relationship between overall glucose control and hypoglycemia (Oliver et al., Diabetes Care 43:53, 2020). The glucose management indicator (GMI) is an estimate of A1C derived from the CGM system’s mean estimated glucose value (EGV) (Bergenstal et al., Diabetes Care 41:2275, 2018). We analyzed real-world evidence of the relationship between the GMI and exposure to hypoglycemia. Data were from an anonymized convenience sample of US-based users of the G6 CGM system (Dexcom, Inc., San Diego, CA) who used a mobile device to upload EGVs in the third quarter of 2020. Only data from people who had uploaded ≥80% of possible values were included. Each person’s GMI was calculated as GMI = 3.31 + (0.02392 × mean EGV [mg/dL]). Each person’s exposure to hypoglycemia was estimated as the percentage of EGVs &lt;70 mg/dL or &lt;54 mg/dL (%&lt;70 and %&lt;54, respectively). Patients were grouped into 6 categories according to GMI values &lt;6.5%, 6.5 to 6.9%, 7.0 to 7.4%, 7.5 to 7.9%, 8.0 to 8.4%, and ≥8.5%. Mean %&lt;70 mg/dL and %&lt;54 mg/dL were both inversely correlated with GMI, decreasing monotonically as the GMI category increased. GMI category, %&lt;70, and %&lt;54 are as follows: (&lt;6.5%: 5.27%, 1.13%); (6.5 to 6.9%: 2.84%, 0.59%); (7.0 to 7.4%: 1.95%, 0.41%); (7.5 to 7.9%: 1.46%, 0.31%); (8.0 to 8.4%: 1.14%, 0.25%); (≥8.5%: 0.69%, 0.17%). However, in all GMI categories except for the “&lt;6.5%” category, the extent of hypoglycemic exposure was below the consensus targets proposed by Battelino et al. (Diabetes Care 42:1593, 2019) of &lt;4% for EGVs &lt;70 mg/dL and &lt;1% for EGVs &lt;54 mg/dL. The approach of elevating A1C targets to reduce hypoglycemia risk is not supported by real-world evidence for CGM users who have GMI or A1C values ≥6.5%. CGM users can safely strive for A1C values &lt;7.0%.

Predicting Antibody Developability Profiles Through Early Stage Discovery Screening

Monoclonal antibodies play an increasingly important role for the development of new drugs across multiple therapy areas. The term 'developability' encompasses the feasibility of molecules to successfully progress from discovery to development via evaluation of their physicochemical properties. These properties include the tendency for self-interaction and aggregation, thermal stability, colloidal stability, and optimization of their properties through sequence engineering. Selection of the best antibody molecule based on biological function, efficacy, safety, and developability allows for a streamlined and successful CMC phase. An efficient and practical high-throughput developability workflow (100 s-1,000 s of molecules) implemented during early antibody generation and screening is crucial to select the best lead candidates. This involves careful assessment of critical developability parameters, combined with binding affinity and biological properties evaluation using small amounts of purified material (<1 mg), as well as an efficient data management and database system. Herein, a panel of 152 various human or humanized monoclonal antibodies was analyzed in biophysical property assays. Correlations between assays for different sets of properties were established. We demonstrated in two case studies that physicochemical properties and key assay endpoints correlate with key downstream process parameters. The workflow allows the elimination of antibodies with suboptimal properties and a rank ordering of molecules for further evaluation early in the candidate selection process. This enables any further engineering for problematic sequence attributes without affecting program timelines.

Space Medicine: Why Do Recently Published Papers about Telomere Length Alterations Increase our Uncertainty Rather than Reduce it?

There is a growing interest in examining alterations in telomere length as a reliable biomarker of general health, as well as a marker for predicting later morbidity and mortality. Substantial evidence shows that telomere length is associated with aging; telomere shortening acts as a "counting mechanism" that drives replicative senescence by limiting the mitotic potential of normal (but not malignant) cells. In this Correspondence, we attempt to answer the question of why recently published papers about telomere length alterations increase our uncertainty rather than reduce it. This discussion includes three major research areas regarding telomere length: environmental stressors, aging, and life span. Our review suggests that activation of telomerase activity due to stressors in space might be a double-edged sword with both favorable and unfavorable consequences. The selection of an effect's consequence must clearly elucidate the experimental conditions as well as associated stressors. In this Correspondence, we attempt to answer the question of why recently published papers about telomere length alterations increase our uncertainty rather than reduce it. The selection of an effect's consequence must clearly elucidate the experimental conditions as well as associated stressors. Both positive and negative consequences must be clearly addressed in order to bolster the conclusions, as well as identify future research directions.

Non-inferiority trials using a surrogate marker as the primary endpoint: An increasing phenotype in cardiovascular trials

BACKGROUND/AIMS

Non-inferiority trials are increasing in cardiovascular medicine, with approval of many drugs and devices on the basis of such studies. Surrogate markers as primary endpoints have been also more frequently used for efficient assessment of cardiovascular interventions. However, there is uncertainty about their concordance with clinical outcomes. Non-inferiority design using a surrogate marker as a primary endpoint may pose particular challenges in clinical interpretation. We sought to explore the publication trends, methodology, and reporting features of non-inferiority cardiovascular trials that used a primary surrogate marker as the primary endpoint.

METHODS

We searched six high-impact journals (The New England Journal of Medicine, The Journal of the American Medical Association, The Lancet, The Journal of the American College of Cardiology, Circulation, and European Heart Journal) from 1 January 1990 to 31 December 2018 and identified non-inferiority cardiovascular trials that used a surrogate marker as the primary endpoint. We assessed the non-inferiority margin reported in the manuscript and other publicly available platforms (e.g. protocol, clinicaltrials.gov). We also determined whether the included non-inferiority trials with surrogate markers as primary endpoints were followed by clinical outcome trials.

RESULTS

We screened 15,553 publications and identified 247 cardiovascular trials that used a non-inferiority design. Of these, 37 had a surrogate marker as a primary endpoint (18 drug trials, 13 device trials, 6 others). All of these non-inferiority trials with surrogate outcomes were published after 2000, mostly in cardiology journals (13 in The Journal of the American College of Cardiology, 9 in European Heart Journal, 8 in Circulation, 6 in The Lancet, 1 in The New England Journal of Medicine), and their publication rate increased over time (p < 0.001 for linear trend). The median number of patients in the primary analysis was 300 (interquartile range: 202-465). The study protocol or a methods paper was publicly available for only 13 (35.1%) trials, of which the non-inferiority margin was not reported in 4 trials. In 16 studies (43.2%), the manuscript did not acknowledge the limitations of using a surrogate endpoint or the need for a definitive clinical outcome trial. Thirty-four trials (91.9%) concluded that the tested intervention met non-inferiority criteria. However, only five (13.5%) were followed by clinical outcomes trials the results of which did not always confirm non-inferiority.

CONCLUSION

Non-inferiority trials that use a surrogate marker as the primary endpoint are being increasingly performed. However, these trials pose particular challenges with design, reporting, and interpretation, which are not systematically and consistently addressed or reported.

Highland games: A benchmarking exercise in predicting biophysical and drug properties of monoclonal antibodies from amino acid sequences

Biopharmaceutical product and process development do not yet take advantage of predictive computational modeling to nearly the degree seen in industries based on smaller molecules. To assess and advance progress in this area, spirited coopetition (mutually beneficial collaboration between competitors) was successfully used to motivate industrial scientists to develop, share, and compare data and methods which would normally have remained confidential. The first "Highland Games" competition was held in conjunction with the October 2018 Recovery of Biological Products Conference in Ashville, NC, with the goal of benchmarking and assessment of the ability to predict development-related properties of six antibodies from their amino acid sequences alone. Predictions included purification-influencing properties such as isoelectric point and protein A elution pH, and biophysical properties such as stability and viscosity at very high concentrations. Essential contributions were made by a large variety of individuals, including companies which consented to provide antibody amino acid sequences and test materials, volunteers who undertook the preparation and experimental characterization of these materials, and prediction teams who attempted to predict antibody properties from sequence alone. Best practices were identified and shared, and areas in which the community excels at making predictions were identified, as well as areas presenting opportunities for considerable improvement. Predictions of isoelectric point and protein A elution pH were especially good with all-prediction average errors of 0.2 and 1.6 pH unit, respectively, while predictions of some other properties were notably less good. This manuscript presents the events, methods, and results of the competition, and can serve as a tutorial and as a reference for in-house benchmarking by others. Organizations vary in their policies concerning disclosure of methods, but most managements were very cooperative with the Highland Games exercise, and considerable insight into common and best practices is available from the contributed methods. The accumulated data set will serve as a benchmarking tool for further development of in silico prediction tools.

Abstract 345: Non-inferiority Trials With a Primary Surrogate Endpoint: An Increasing Phenotype in Cardiovascular Trials

Background: Non-inferiority trials are increasing in cardiovascular medicine, with approval of many drugs and devices on the basis of such studies. Surrogate endpoints have been also increasingly used for efficient assessment of cardiovascular interventions, but there is uncertainty about their concordance with clinical outcomes. Non-inferiority designs using a primary surrogate endpoint in cardiovascular trials may pose particular challenges in clinical interpretation.

Methods: We searched six high-impact journals (NEJM, JAMA, Lancet, JACC, Circulation, and EHJ) from 01/01/1990-12/31/2018 and identified non-inferiority cardiovascular trials that used a primary surrogate endpoint. We assessed the non-inferiority margin reported in the manuscript and other publicly available platforms (e.g. protocol, clinicaltrials.gov). We determined whether surrogate outcome non-inferiority trials were followed by clinical outcome trials.

Results: We screened 15,553 publications and identified 247 cardiovascular trials that used a non-inferiority design. Of these, 37 had a primary surrogate endpoint (18 drug trials, 13 device trials, 6 others). All of these non-inferiority trials with surrogate outcomes were published after 2000, mostly in cardiology journals (13 in JACC, 9 in European Heart Journal, 8 in Circulation, 6 in Lancet, 1 in NEJM), and their publication rate increased over time (P<0.001 for linear trend). The median number of patients in the primary analysis was 263 (IQR: 191 - 460). The study protocol or a methods paper was publicly available for only 12 (32.4%) trials, of which the non-inferiority margin was not reported in 4. In 16 (43.2%) studies the manuscript did not acknowledge the limitations of using a surrogate endpoint, or the need for a definitive clinical outcome trial. Thirty-four trials (91.9%) concluded that the tested intervention met non-inferiority ocriteria. However, only 3 (9.1%) were followed by clinical outcomes trials the results of which did not always confirm non-inferiority (Figure).

Conclusion: Non-inferiority trials with a primary surrogate endpoint are being increasingly performed. However, these trials pose particular challenges with design, reporting and interpretation, which are not systematically and consistently addressed or reported.

Identifying long-term psychological distress from single measures: evidence from a nationally representative longitudinal survey of the Australian population

BACKGROUND

Single time-point assessments of psychological distress are often used to indicate chronic mental health problems, but the validity of this approach is unclear. The aims of this study were to investigate how a single assessment of distress relates to longer-term assessment and quantify misclassification from using single measures to indicate chronic distress.

METHODS

Data came from the Household, Income and Labour Dynamics in Australia Survey, a nationally representative study of Australian adults. Psychological distress, measured with the Kessler10 and categorised into low (scores:10- < 12), mild (12- < 16), moderate (16- < 22) and high (22-50), has been assessed in the Survey biennially since wave 7. Among respondents who were aged ≥25 years and participated in all waves in which distress was measured, we describe agreement in distress categories, and using a mixed linear model adjusting for age and sex we estimate change in scores, over a two-, four-, six- and eight-year follow-up period. We applied weights, benchmarked to the Australian population, to all analyses.

RESULTS

Two-years following initial assessment, proportions within identical categories of distress were 66.0% for low, 54.5% for mild, 44.0% for moderate and 50.3% for high, while 94.1% of those with low distress initially had low/mild distress and 81.4% with high distress initially had moderate/high distress. These patterns did not change materially as follow-up time increased. Over the full eight-year period, 77.3% of individuals with high distress initially reported high distress on ≥1 follow-up occasion. Age-and sex- adjusted change in K10 scores over a two-year period was 1.1, 0.5, - 0.7 and - 4.9 for low, mild, moderate and high distress, respectively, and also did not change materially as follow-up time increased.

CONCLUSION

In the absence of repeated measures, single assessments are useful proxies for chronic distress. Our estimates could be used in bias analyses to quantify the magnitude of the bias resulting from use of single assessments to indicate chronic distress.

Automated High-Throughput Capillary Circular Dichroism and Intrinsic Fluorescence Spectroscopy for Rapid Determination of Protein Structure

Assessing the physical stability of proteins is one of the most important challenges in the development, manufacture, and formulation of biotherapeutics. Here, we describe a method for combining and automating circular dichroism and intrinsic protein fluorescence spectroscopy. By robotically injecting samples from a 96-well plate into an optically compliant capillary flow cell, complementary information about the secondary and tertiary structural state of a protein can be collected in an unattended manner from considerably reduced volumes of sample compared to conventional techniques. We demonstrate the accuracy and reproducibility of this method. Furthermore, we show how structural screening can be used to monitor unfolding of proteins in two case studies using (i) a chaotropic denaturant (urea) and (ii) low-pH buffers used for monoclonal antibody (mAb) purification during Protein A chromatography.

Percutaneous Coronary Intervention in Patients Without Acute Myocardial Infarction in China: Results From the China PEACE Prospective Study of Percutaneous Coronary Intervention

IMPORTANCE

Despite a rapid increase in percutaneous coronary intervention (PCI) procedures in China, little is known about patient-reported health status before and after PCI in patients without acute myocardial infarction (AMI).

OBJECTIVE

To describe self-perceived angina-specific health status prior to PCI and 1 year after the procedure in patients without AMI in China.

DESIGN, SETTING, AND PARTICIPANTS

The China Patient-Centered Evaluative Assessment of Cardiac Events (PEACE) Prospective Study of PCI was a population-based, multicenter cohort study of a consecutive sample of 1611 patients without AMI undergoing elective PCI. Participants were enrolled from 40 hospitals in 18 provinces in China from December 2012 to August 2014. Participants were eligible if they underwent PCI for stable and unstable angina and did not have AMI. Participants were excluded if they died in hospital, withdrew from follow-up, or had missing data on self-reported health status at baseline or at 1 year after PCI. The date of the analysis was September 15, 2018.

EXPOSURES

Percutaneous coronary intervention for ischemic heart disease.

MAIN OUTCOMES AND MEASURES

Angina frequency and angina-related quality of life were assessed with the Seattle Angina Questionnaire (SAQ) immediately prior to PCI and 1 year after the procedure. Either (1) an increase in the SAQ Angina Frequency score of 10 or more points or (2) an increase in the SAQ Quality-of-Life score of 10 or more points was considered to represent clinically significant improvement.

RESULTS

Of 1611 patients, 520 (32.3%) were women; mean (SD) age was 61.3 (9.8) years. Among these patients, 443 (27.5%) had stable coronary artery disease and 1168 (72.5%) had unstable angina. One hundred fourteen of 443 patients undergoing PCI for stable coronary artery disease (25.7%) and 175 of 1168 undergoing PCI for unstable angina (15.0%) had no reported angina symptoms at the time of the procedure (SAQ Angina Frequency score = 100). Moreover, 18% of all patients (290) had minimal angina symptoms (SAQ Angina Frequency score >90) and, thus, no potential for substantial clinical improvement. Patients with smaller clinical improvements in angina symptom burden at 1 year following PCI had significantly higher baseline SAQ scores for all scales than patients with greater clinical improvement, but generally similar sociodemographic and procedural characteristics.

CONCLUSIONS AND RELEVANCE

In this study, 25.7% of patients undergoing PCI for stable coronary artery disease had no reported angina symptoms at the time of the procedure. Patients with smaller clinical improvements in angina symptom burden had higher baseline SAQ scores, which highlights the importance of ascertaining impairment from angina among patients without AMI prior to performing PCI.

Neutrophil accumulation and NET release contribute to thrombosis in HIT

Heparin-induced thrombocytopenia (HIT) is an immune-mediated thrombocytopenic disorder associated with a severe prothrombotic state. We investigated whether neutrophils and neutrophil extracellular traps (NETs) contribute to the development of thrombosis in HIT. Using an endothelialized microfluidic system and a murine passive immunization model, we show that HIT induction leads to increased neutrophil adherence to venous endothelium. In HIT mice, endothelial adherence is enhanced immediately downstream of nascent venous thrombi, after which neutrophils undergo retrograde migration via a CXCR2-dependent mechanism to accumulate into the thrombi. Using a microfluidic system, we found that PF4 binds to NETs, leading them to become compact and DNase resistant. PF4-NET complexes selectively bind HIT antibodies, which further protect them from nuclease digestion. In HIT mice, inhibition of NET formation through Padi4 gene disruption or DNase treatment limited venous thrombus size. PAD4 inactivation did affect arterial thrombi or severity of thrombocytopenia in HIT. Thus, neutrophil activation contributes to the development of venous thrombosis in HIT by enhancing neutrophil-endothelial adhesion and neutrophil clot infiltration, where incorporated PF4-NET-HIT antibody complexes lead to thrombosis propagation. Inhibition of neutrophil endothelial adhesion, prevention of neutrophil chemokine-dependent recruitment of neutrophils to thrombi, or suppression of NET release should be explored as strategies to prevent venous thrombosis in HIT.

Age of Data at the Time of Publication of Contemporary Clinical Trials

IMPORTANCE

As medical knowledge and clinical practice rapidly evolve over time, there is an imperative to publish results of clinical trials in a timely way and reduce unnecessary delays.

OBJECTIVES

To characterize the age of clinical trial data at the time of publication in journals with a high impact factor and highlight the time from final data collection to publication.

DESIGN AND SETTING

A cross-sectional analysis was conducted of all randomized clinical trials published from January 1 through December 31, 2015, in the Annals of Internal Medicine, BMJ, JAMA, JAMA Internal Medicine, Lancet, and New England Journal of Medicine. Multivariable linear regression analyses were conducted to assess whether data age (adjusted for follow-up duration) and publication time were associated with trial characteristics.

MAIN OUTCOMES AND MEASURES

The outcome measures were the midpoint of data collection until publication (data age), the time from first participant enrollment to last participant enrollment (enrollment time), and the time from final data collection to publication (publication time).

RESULTS

There were 341 clinical trials published in 2015 by the 6 journals. For assessment of the primary end point, 37 trials (10.9%) had a follow-up period of less than 1 month, 172 trials (50.4%) had a follow-up period of 1 month to 1 year, and 132 trials (38.7%) had a follow-up period of more than 1 year. For all trials, the median data age at publication was 33.9 months (interquartile range, 23.5-46.3 months). Among trials with a follow-up period of 1 month or less, the median data age was 30.6 months (interquartile range, 18.6-39.0 months). A total of 68 trials (19.9%) required more than 4 years to complete enrollment. The median time from the completion of data collection to publication was 14.8 months (interquartile range, 7.4-22.2 months); publication time was 2 or more years in 63 trials (18.5%). In multivariable regression analyses adjusted for follow-up time, inconclusive or unfavorable trial results were significantly associated with older data age (>235 days). Compared with trials funded only by private industry, trials funded by government were associated with a significantly longer time to publication (>180 days).

CONCLUSIONS AND RELEVANCE

Clinical trials in journals with a high impact factor were published with a median data age of nearly 3 years. For a substantial proportion of studies, time for enrollment and time from completion of data collection to publication were quite long, indicating marked opportunities for improvement in clinical trials to reduce data age.

Identifying county characteristics associated with resident well-being: A population based study

Background

Well-being is a positively-framed, holistic assessment of health and quality of life that is associated with longevity and better health outcomes. We aimed to identify county attributes that are independently associated with a comprehensive, multi-dimensional assessment of individual well-being.

Methods

We performed a cross-sectional study examining associations between 77 pre-specified county attributes and a multi-dimensional assessment of individual US residents’ well-being, captured by the Gallup-Sharecare Well-Being Index. Our cohort included 338,846 survey participants, randomly sampled from 3,118 US counties or county equivalents.

Findings

We identified twelve county-level factors that were independently associated with individual well-being scores. Together, these twelve factors explained 91% of the variance in individual well-being scores, and they represent four conceptually distinct categories: demographic (% black); social and economic (child poverty, education level [<high school, high school diploma/equivalent, college degree], household income, % divorced); clinical care (% eligible women obtaining mammography, preventable hospital stays per 100,000, number of federally qualified health centers); and physical environment (% commuting by bicycle and by public transit).

Conclusions

Twelve factors across social and economic, clinical care, and physical environmental county-level factors explained the majority of variation in resident well-being.

Risks of restrictive red blood cell transfusion strategies in patients with cardiovascular disease (CVD): a meta-analysis

AIM

To evaluate the risks of restrictive red blood cell transfusion strategies (haemoglobin 7-8 g dL^-1 ) in patients with and without known cardiovascular disease (CVD).

BACKGROUND

Recent guidelines recommend restrictive strategies for CVD patients hospitalised for non-CVD indications, patients without known CVD and patients hospitalised for CVD corrective procedures.

METHODS/MATERIALS

Database searches were conducted through December 2017 for randomised clinical trials that enrolled patients with and without known CVD, hospitalised either for CVD-corrective procedures or non-cardiac indications, comparing effects of liberal with restrictive strategies on major adverse coronary events (MACE) and death.

RESULTS

In CVD patients not undergoing cardiac interventions, a liberal strategy decreased (P = 0·01) the relative risk (95% CI) (RR) of MACE [0·50 (0·29-0·86)] (I²  = 0%). Among patients without known CVD, the incidence of MACE was lower (1·7 vs 3·9%), and the effect of a liberal strategy on MACE [0·79, (0·39-1·58)] was smaller and non-significant but not different from CVD patients (P = 0·30). Combining all CVD and non-CVD patients, a liberal strategy decreased MACE [0·59, (0·39-0·91); P = 0·02]. Conversely, among studies reporting mortality, a liberal strategy decreased mortality in CVD patients (11·7% vs·13·3%) but increased mortality (19·2% vs 18·0%) in patients without known CVD [interaction P = 0·05; ratio of RR 0·73, (0·53-1·00)]. A liberal strategy also did not benefit patients undergoing cardiac surgery; data were insufficient for percutaneous cardiac procedures.

CONCLUSIONS

In patients hospitalised for non-cardiac indications, liberal transfusion strategies are associated with a decreased risk of MACE in both those with and without known CVD. However, this only provides a survival benefit to CVD patients not admitted for CVD-corrective procedures.

Differential gene expression induced by anti-cancer agent plumbagin is mediated by androgen receptor in prostate cancer cells

Treatment of mice harboring PTEN-P2 tumors in the prostate or on prostate tissue in vivo with 5-hydroxy-2-methyl-1,4-naphthoquinone, also known as plumbagin, results in tumor regression in castrated mice, but not in intact mice. This suggested that dihydrotestosterone (DHT) production in the testes may prevent cell death due to plumbagin treatment, but the underlying mechanism is not understood. We performed RNA-seq analysis on cells treated with combinations of plumbagin and DHT, and analyzed differential gene expression, to gain insight into the interactions between androgen and plumbgin. DHT and plumbagin synergize to alter the expression of many genes that are not differentially regulated by either single agent when used alone. These experiments revealed that, for many genes, increases in mRNAs caused by DHT are sharply down-regulated by plumbagin, and that many transcripts change in response to plumbagin in a DHT-dependent manner. This suggests that androgen receptor mediates some of the effects of plumbagin on gene expression.

Plumbagin improves the efficacy of androgen deprivation therapy in prostate cancer: A pre-clinical study

BACKGROUND

Plumbagin is a candidate drug for the treatment of prostate cancer. Previous observations indicated that it may improve the efficacy of androgen deprivation therapy (ADT). This study evaluates the effectiveness of treatment with combinations of plumbagin and alternative strategies for ADT in mouse models of prostate cancer to support its clinical use.

METHODS

Plumbagin was administered per oral in a new sesame oil formulation. Standard toxicology studies were performed in rats. For tumor growth studies, mouse prostate cancer cell spheroids were placed on top of grafted prostate tissue in a dorsal chamber and allowed to form tumors. Mice were separated in various treatment groups and tumor size was measured over time by intra-vital microscopy. Survival studies were done in mice after injection of prostate cancer cells in the prostate of male animals. Androgen receptor (AR) levels were analyzed by Western blot from prostate cancer cells treated with plumbagin.

RESULTS

Plumbagin caused a decrease in AR levels in vitro. In mice, plumbagin at 1 mg/kg in sesame oil displayed low toxicity and caused a 50% tumor regression when combined with castration. The combination of plumbagin with various forms of chemical ADT including treatment with a GnRH receptor agonist, a GnRH receptor antagonist, or CYP17A1 inhibitors, outperformed ADT alone, increasing mouse survival compared to the standard regimen of castration alone. In contrast, the combination of plumbagin with AR antagonists, such as bicalutamide and enzalutamide, showed no improvement over AR antagonists alone. Thus, plumbagin is effective in combination with drugs that prevent the synthesis of testosterone or its conversion to dihydrotestosterone, but not with drugs that bind to AR.

CONCLUSION

Plumbagin significantly improves the effect of ADT drugs currently used in the clinic, with few side effects in mice.

Sex Differences in Trajectories of Risk After Rehospitalization for Heart Failure, Acute Myocardial Infarction, or Pneumonia

BACKGROUND

Women have an increased risk of rehospitalization in the immediate postdischarge period; however, few studies have determined how readmission risk dynamically changes on a day-to-day basis over the full year after hospitalization by sex and how these differences compare with the risk for mortality.

METHODS AND RESULTS

We identified >3 000 000 hospitalizations of patients with a principal discharge diagnosis of heart failure, acute myocardial infarction, or pneumonia and estimated sex differences in the daily risk of rehospitalization/death 1 year after discharge from a population of Medicare fee-for-service beneficiaries aged 65 years and older. We calculated the (1) time required for adjusted rehospitalization/mortality risks to decline 50% from maximum values after discharge, (2) time required for the adjusted readmission risk to approach plateau periods of minimal day-to-day change, and (3) extent to which adjusted risks are greater among recently hospitalized patients versus Medicare patients. We identified 1 392 289, 530 771, and 1 125 231 hospitalizations for heart failure, acute myocardial infarction, and pneumonia, respectively. The adjusted daily risk of rehospitalization varied by admitting condition (hazard rate ratio for women versus men, 1.10 for acute myocardial infarction; hazard rate ratio, 1.04 for heart failure; and hazard rate ratio, 0.98 for pneumonia). However, for all conditions, the adjusted daily risk of death was higher among men versus women (hazard rate ratio women versus with men, <1). For both sexes, there was a similar timing of peak daily risk, half daily risk, and reaching plateau.

CONCLUSIONS

Although the association of sex with daily risk of rehospitalization varies across conditions, women are at highest risk after discharge for acute myocardial infarction. Future studies should focus on understanding the determinants of sex differences in rehospitalization risk among conditions.

Universal label-free in-process quantification of influenza virus-like particles

Virus-like particles (VLPs) are becoming established as vaccines, in particular for influenza pandemics, increasing the interest in the development of VLPs manufacturing bioprocess. However, for complex VLPs, the analytical tools used for quantification are not yet able to keep up with the bioprocess progress. Currently, quantification for Influenza relies on traditional methods: hemagglutination assay or Single Radial Immunodiffusion. These analytical technologies are time-consuming, cumbersome, and not supportive of efficient downstream process development and monitoring. Hereby we report a label-free tool that uses Biolayer interferometry (BLI) technology applied on an Octet platform to quantify Influenza VLPs at all stages of bioprocess. Human (α2,6-linked sialic acid) and avian (α2,3-linked sialic acid) biotinylated receptors associated with streptavidin biosensors were used, to quantify hemagglutinin content in several mono- and multivalent Influenza VLPs. The applied method was able to quantify hemagglutinin from crude samples up to final bioprocessing VLP product. BLI technology confirmed its value as a high throughput analytical tool with high sensitivity and improved detection limits compared to traditional methods. This simple and fast method allowed for real-time results, which are crucial for in-line monitoring of downstream processing, improving process development, control and optimization.

Abstract 124: Recovery From Acute Myocardial Infarction in China: A Report From China PEACE Prospective Study of Acute Myocardial Infarction

Introduction: Despite a dramatic increase in the incidence of acute myocardial infarction (AMI) in China, little is known about patient’s health status in the year following discharge. We studied the change in angina frequency and angina-related quality of life at 1 year after AMI among Chinese patients.

Methods: Among 3,336 patients admitted for AMI to 53 hospitals from December 2012 to May 2014 in the China PEACE Prospective Study of Acute Myocardial Infarction, Angina frequency and angina-related quality of life were assessed with the Seattle Angina Questionnaire (SAQ) at the time of hospitalization and 1 year later. Scores ranged from 0 to 100 points, with higher scores indicating fewer symptoms and better quality of life. We categorized both 1-year scores and changes in scores to support clinical interpretability. We considered a clinically poor outcome at 1 year to be an angina frequency score ≤ 60 (daily/weekly angina) or quality of life score ≤ 50 (poor/fair quality of life). A 1-year change in score ≥ 5 was improvement, a change between -5 and 5 was interpreted as no change, and ≤ -5 was interpreted as being significantly worse at 1 year than before the AMI.

Results: Participants’ average age was 60.6 years (±11.9) and 22.8% were women. The response rate was about 75% and non-responders had similar characteristics compared with responders. At baseline, the mean scores were 86.3±21.9 for angina frequency and 66.7±24.0 for quality of life, with 16.3% having daily/weekly angina and 38.8% poor quality of life. One year later, 36.3% of patients had had a clinically important improvement in angina, 49.0% had no change, and 14.7% had worse symptoms. Similarly, 52.7% experienced a clinically important improvement in quality of life, 18.2% had no change, and 29.1% had worse quality of life. At 1 year after AMI, 5.5% of patients still had severe angina symptoms and 20.9% had poor quality of life.

Conclusion: There is substantial variability in Chinese patients’ symptom and quality of life recovery after AMI and more work is needed to understand the causes of this variability and how best to improve symptoms and quality of life after AMI in China.

Abstract P5-05-04: Vitamin K dependent gamma-carboxylation in breast cancer

The secreted protein periostin (PN) is strongly linked to breast cancer aggressiveness and serum PN is a promising marker of disease activity. However, the regulation and function of PN in relation to the cancer phenotype has yet to be clearly defined. PN is one of the rare proteins (&lt;15 in mammalian systems) that is subject to the post-translational addition of γ-carboxylated glutamatic acid (GLA) residues. However, no studies have addressed whether γ-carboxylation of PN has functional relevance in breast cancer, despite evidence that the proteins that catalyze γ-carboxylation are expressed in normal mammary gland. Using publically available datasets we found that GGCX, VKORC1 and VKORC1L1 (genes that mediate γ-carboxylation) are overexpressed in 24% of breast cancers. Furthermore, survival of patients whose tumors overexpress these genes is significantly worse than that of patients whose tumors do not overexpress these genes. Follow-up studies utilized the Human Protein Atlas to examine expression of GGCX, VKORC1 and VKORC1L1 proteins in normal breast and invasive ductal carcinomas (IDC). Normal ductal epithelial cells showed intense staining for GGCX, patchy moderate staining for VKORC1 and diffuse low signal for VKORC1L1. All cases of IDC exhibited strong staining for GGCX, 80% had moderate-intense staining for VKORC1 and 77% had diffuse but low staining for VKORC1L1. Staining for all 3 proteins was localized only in tumor cells indicating that stromal cells are unlikely to contribute to protein γ-carboxylation. Next we explored expression of the γ-carboxylation pathway genes using in vitro models of epithelial-mesenchymal transition (EMT) and tumor progression. The EMT model consists of human mammary epithelial cells immortalized with telomerase and SV40 (HMLE cells) that constitutively express GFP (control), TWIST, SNAIL or TGFβ. Relative to control cells, GGCX, VKORC1 and VKORC1L1 were up-regulated in HMLE-TWIST cells, GGCX and VKORC1 were up-regulated in HMLE-SNAIL cells and VKORC1 was up-regulated in HMLE-TGFβ cells. These data suggest that γ-carboxylation may be triggered early in breast cancer oncogenesis. In the tumor progression model, we found up-regulation of GGCX and VKORC1 in HMLE+RAS cells relative to HMLE cells. Introduction of SV40 alone did not alter expression of these genes. In HMLE-TWIST and HMLE-RAS cells with the highest expression of GGCX, VKORC1 and VKORC1L1, PN was up-regulated 200-300-fold, supporting the concept that PN may be a relevant target for γ-carboxylation during EMT and tumor progression. In summary, available genomic and proteomic data suggest that the vitamin K dependent pathway genes GGCX, VKORC1 and VKORC1L1 are present in normal mammary gland but up-regulated in a subset of invasive breast cancers that are characterized by poor overall survival. Genes in this pathway are also up-regulated in mammary epithelial cells expressing triggers of EMT (particularly TWIST) or oncogenes such as RAS. Since the only known function of these genes is in γ-carboxylation, studies to confirm PN as a GGCX substrate and to identify additional γ-carboxylated proteins and their functions in breast cancer are clearly warranted. Our limited understanding of this ancient, conserved pathway may be masking an important therapeutic opportunity.

Citation Format: Welsh J, Beaudin S, Tenniswood M. Vitamin K dependent gamma-carboxylation in breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-05-04.

Trajectories of Risk for Specific Readmission Diagnoses after Hospitalization for Heart Failure, Acute Myocardial Infarction, or Pneumonia

BACKGROUND

The risk of rehospitalization is elevated in the immediate post-discharge period and declines over time. It is not known if the extent and timing of risk vary across readmission diagnoses, suggesting that recovery and vulnerability after discharge differ by physiologic system.

OBJECTIVE

We compared risk trajectories for major readmission diagnoses in the year after discharge among all Medicare fee-for-service beneficiaries hospitalized with heart failure (HF), acute myocardial infarction (AMI), or pneumonia from 2008-2010.

METHODS

We estimated the daily risk of rehospitalization for 12 major readmission diagnostic categories after accounting for the competing risk of death after discharge. For each diagnostic category, we identified (1) the time required for readmission risk to peak and then decline 50% from maximum values after discharge; (2) the time required for readmission risk to approach plateau periods of minimal day-to-day change; and (3) the extent to which hospitalization risks are higher among patients recently discharged from the hospital compared with the general elderly population.

RESULTS

Among >3,000,000 hospitalizations, the yearly rate of rehospitalization was 67.0%, 49.5%, and 55.3% after hospitalization for HF, AMI, and pneumonia, respectively. The extent and timing of risk varied by readmission diagnosis and initial admitting condition. Risk of readmission for gastrointestinal bleeding/anemia peaked particularly late after hospital discharge, occurring 10, 6, and 7 days after hospitalization for HF, AMI, and pneumonia, respectively. Risk of readmission for trauma/injury declined particularly slowly, requiring 38, 20, and 38 days to decline by 50% after hospitalization for HF, AMI, and pneumonia, respectively.

CONCLUSIONS

Patterns of vulnerability to different conditions that cause rehospitalization vary by time after hospital discharge. This finding suggests that recovery of various physiologic systems occurs at different rates and that post-discharge interventions to minimize vulnerability to specific conditions should be tailored to their underlying risks.

Transfusion of recently donated (fresh) red blood cells (RBCs) does not improve survival in comparison with current practice, while safety of the oldest stored units is yet to be established: a meta-analysis

BACKGROUND AND OBJECTIVES

Preclinical studies generated the hypothesis that older stored red blood cells (RBCs) can increase transfusion risks. To examine the most updated and complete clinical evidence and compare results between two trial designs, we assessed both observational studies and randomized controlled trials (RCTs) studying the effect of RBC storage age on mortality.

MATERIALS AND METHODS

Five databases were searched through December 2014 for studies comparing mortality using transfused RBCs having longer and shorter storage times.

RESULTS

Analysis of six RCTs found no significant differences in survival comparing current practice (average storage age of 2 to 3 weeks) to transfusion of 1- to 10-day-old RBCs (OR 0·91, 95% CI 0·77-1·07). RBC storage age was lower in RCTs vs. observational studies (P = 0·01). The 31 observational studies found an increased risk of death (OR 1·13, 95% CI 1·03-1·24) (P = 0·01) with increasing age of RBCs, a different mortality effect than RCTs (P = 0·02).

CONCLUSION

RCTs established that transfusion of 1- to 10-day-old stored RBCs is not superior to current practice. The apparent discrepancy in mortality between analyses of RCTs and observational studies may in part relate to differences in hypotheses tested and ages of stored RBCs studied. Further trials investigating 1- to 10-day-old stored RBC benefits would seem of lower priority than studies to determine whether 4- to 6-week stored units have safety and efficacy equivalent to the 2- to 3-week-old stored RBCs commonly transfused today.

Project Baiterek: A Patient Access Program to Improve Clinical Outcomes and Quality of Life in Children with Type 1 Diabetes in Kazakhstan

Diabetes is a key driver in the rise of noncommunicable diseases globally. It causes expensive and burdensome short- and long-term complications, with both an economic and social impact. In many countries, however, access to care and disease management in type 1 diabetes is suboptimal, increasing the risk for complications. In 2011, Project Baiterek was initiated as a collaborative effort between the Kazakhstan Ministry of Health, industry (Medtronic Plc), local physicians, and the Diabetes Association of the Republic of Kazakhstan to enhance patient access to continuous subcutaneous insulin infusion (CSII) therapy. It was the first countrywide project to provide equity and universal access to insulin pump therapy among children with type 1 diabetes, increasing pump use from zero to two-thirds of this population in less than 3 years. The project also involved instigating longitudinal data collection, and long-term clinical outcomes continue to be monitored. Here, we provide an overview of the clinical, quality-of-life, and economic outcomes to date associated with providing CSII therapy to children with type 1 diabetes in Kazakhstan. Initial clinical data show that CSII therapy improved clinical outcomes and quality of life for patients entered into the program and that CSII therapy was cost-effective relative to multiple daily injection therapy. The positive outcomes of Project Baiterek provide a template for similar patient access programs in other settings, and its framework could be adapted to initiatives to change health care infrastructures and standards of care for other noncommunicable diseases.

Effects of different tissue microenvironments on gene expression in breast cancer cells

In metastasis, circulating tumor cells penetrate the walls of blood vessels and enter the metastatic target tissue, thereby becoming exposed to novel and relatively unsupportive microenvironments. In the new microenvironments, the tumor cells often remain in a dormant state indefinitely and must adapt before they are able to successfully colonize the tissue. Very little is known about this adaptive process. We studied temporal changes in gene expression when breast cancer cells adapt to survive and grow on brain, bone marrow, and lung tissue maintained in an in vivo culture system, as models of the metastatic colonization of these tissues. We observed the transient activation of genes typically associated with homeostasis and stress during the initial stages of adaptation, followed by the activation of genes that mediate more advanced functions, such as elaboration of cell morphology and cell division, as the cells adapted to thrive in the host tissue microenvironment. We also observed the temporary induction of genes characteristic of the host tissue, which was particularly evident when tumor cells were grown on brain tissue. These early transient gene expression events suggest potential points of therapeutic intervention that are not evident in data from well-established tumors.

Primate cerebellar granule cells exhibit a tonic GABAAR conductance that is not affected by alcohol: a possible cellular substrate of the low level of response phenotype

In many rodent brain regions, alcohol increases vesicular release of GABA, resulting in an increase in the frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) and the magnitude of tonic GABAA receptor (GABAAR) currents. A neglected issue in translating the rodent literature to humans is the possibility that phylogenetic differences alter the actions of alcohol. To address this issue we made voltage-clamp recordings from granule cells (GCs) in cerebellar slices from the non-human primate (NHP), Macaca fascicularis. We found that similar to Sprague Dawley rats (SDRs), NHP GCs exhibit a tonic conductance generated by α6δ subunit containing GABAARs, as evidenced by its blockade by the broad spectrum GABAAR antagonist, GABAzine (10 μM), inhibition by α6 selective antagonist, furosemide (100 μM), and enhancement by THDOC (10-20 nM) and THIP (500 nM). In contrast to SDR GCs, in most NHP GCs (~60%), application of EtOH (25-105 mM) did not increase sIPSC frequency or the tonic GABAAR current. In a minority of cells (~40%), EtOH did increase sIPSC frequency and the tonic current. The relative lack of response to EtOH was associated with reduced expression of neuronal nitric oxide synthase (nNOS), which we recently reported mediates EtOH-induced enhancement of vesicular GABA release in rats. The EtOH-induced increase in tonic GABAAR current was significantly smaller in NHPs than in SDRs, presumably due to less GABA release, because there were no obvious differences in the density of GABAARs or GABA transporters between SDR and NHP GCs. Thus, EtOH does not directly modulate α6δ subunit GABAARs in NHPs. Instead, EtOH enhanced GABAergic transmission is mediated by enhanced GABA release. Further, SDR GC responses to alcohol are only representative of a subpopulation of NHP GCs. This suggests that the impact of EtOH on NHP cerebellar physiology will be reduced compared to SDRs, and will likely have different computational and behavioral consequences.