Post-acute COVID-19 complications in UK doctors: results of a cross-sectional survey

BACKGROUND

As a consequence of their occupation, doctors and other healthcare workers were at higher risk of contracting coronavirus disease 2019 (COVID-19), and more likely to experience severe disease compared to the general population. However, systematic information on post-acute COVID complications in doctors is very limited.

AIMS

This study aimed to determine the symptoms, perceived determinants, health and occupational impact, and consequent needs relating to post-acute COVID complications in UK doctors.

METHODS

An online cross-sectional survey was distributed to UK doctors self-identifying as having Long COVID or other post-acute COVID complications.

RESULTS

Of 795 responses, 603 fulfilled the inclusion criteria of being a UK-based medical doctor experiencing one or more post-acute COVID complications. Twenty-eight per cent reported a lack of adequate Respiratory Protective Equipment at the time of contracting COVID-19. Eighteen per cent of eligible respondents reported that they had been unable to return to work since acquiring COVID.

CONCLUSIONS

Post-acute COVID (Long COVID) in UK doctors is a substantial burden for respondents to our questionnaire. The results indicated that insufficient respiratory protection could have contributed to occupational disease, with COVID-19 being contracted in the workplace, and resultant post-COVID complications. Although it may be too late to address the perceived determinants of inadequate protection for those already suffering with Long COVID, more investment is needed in rehabilitation and support of those afflicted.

Inhibition of novel lipoprotein(a) receptor major facilitator superfamily domain containing 5 (MFSD5) reduces development of aortic valve calcification

Funding Acknowledgements

Type of funding sources: Other. Main funding source(s): Private grant from Kowa Pharmaceuticals to Brigham and Woman's Hospital

Calcific aortic valve stenosis (CAVS) is the most prevent valvular heart disease in the western world increasing exponentially with age, with an 112% increase in CAVS deaths in the last three decades; however no therapeutic treatment is currently available. Recently, lipoprotein(a) [Lp(a)] has been demonstrated to be an independent and causal risk factor for CAVS, yet the understanding of its cellular uptake and catabolism is limited thus underscoring the need for further investigation.

This study aimed to determine a target receptor, unique for Lp(a) on the surface of valvular interstitial cells (VICs) and ascertain the role of the receptor on the development of VIC calcification.

Unbiased ligand-receptor capture mass spectrometry (TriCEPS) was used to identify target receptor, with western blotting, ELISA, qPCR, alizarin red calcium staining and immunofluorescence used to validate the targets in vitro via siRNA inhibition and overexpression. Transmission electron microscopy (TEM) was used to determine uptake of Lp(a) within excised human valves. Identification of small molecule inhibitors was assessed computationally via the L1000 dataset, with the top hit candidate validated in vitro. Genotype-phenotype studies were examined using the United Kingdom Biobank (UKBB) and the Millions Veterans Program. Linear regression was used to evaluate association between aortic stenosis and plasma Lp(a) levels, and a phenotype-wide association analysis was then performed against this generated ‘genotype’.

Ligand-receptor capture mass spectrometry was used to detect novel membrane proteins with specific binding to Lp(a); MFSD5, MRC2, LDLR were identified as possible candidates. MFSD5 RNAscope demonstrated its presence in human aortic valves. Lp(a) uptake in VICs was confirmed via western blot and TEM. MFSD5 siRNA significantly reduced dil-labelled Lp(a) uptake in human VICs (p=0.003) and HEPG2 cells (p=0.0003), conversely MFSD5 overexpression increased uptake (p=0.0345, p=0.0318), whilst specificity of MFSD5 to Lp(a) alone was shown via no change in LDL uptake following MFSD5 inhibition (p=0.616, p=0.991). MFSD5 inhibition reduced RUNX2 (p=0.0124) and Osteocalcin (p<0.001) RNA expression and reduced alizarin red staining following culture in Lp(a) osteogenic media for 21 days (p<0.0033). Druggability of MFSD5 was confirmed by the L1000 database, which identified aminopurvalanol as a binding partner for MFSD5 and significantly reduced Lp(a) uptake within VICs (p=0.0091). MFSD5-loss of function within the UKBB showed no significant cardiovascular association, however 50kb +/- of the MFSD5 gene showed nominal association with hyperlipidaemia and atrial fibrillation.

The current study demonstrates the novel Lp(a) receptor MFSD5 may be responsible for uptake of Lp(a) within VICs, resulting in the development of aortic valve calcification, highlighting the need for further exploration into the role of MFSD5 in aortic valve disease.

POS0057 INDUCIBLE REGULATORY SYNOVIAL MACROPHAGES: A PROOF-OF-CONCEPT STUDY FOR A CELL-BASED TARGETED THERAPY FOR RHEUMATOID ARTHRITIS

Background

Infiltration of monocyte-derived macrophages into the synovial tissue (ST) is a hallmark of rheumatoid arthritis (RA) pathology. These macrophages promote inflammation, local joint effusion, and joint damage via the release of cytokines, oxygen reactive species, and tissue damaging enzymes. However, balancing these, are the ‘regulatory’ macrophages with inflammation-resolving properties, characterised by expression of CD206 and MerTK, dominant within the ST of healthy individuals as well as RA patients in remission (1). Indeed, these cells are believed to actively contribute to the maintenance of remission.

Macrophages are known to exhibit remarkable phenotypic plasticity and understanding the role of this characteristic in regulating inflammation and pathology remains a major challenge, as does the characterization of factors in the microenvironment such as the synovium that control such macrophage characteristics. Importantly, whether the infiltrating, inflammatory macrophages of the RA ST similarly exhibit such phenotypic plasticity, and whether this occurs during the process of reaching remission, remains to be studied.

Objectives

We investigated the phenotypic plasticity of inflammatory synovial macrophages from patients with RA in vitro, investigating their ability to convert from an inflammatory macrophage population into ‘regulatory’ CD206+MerTK+ macrophages. These findings will provide a proof-of-concept as to the utility of these macrophage for a cell-based therapy in resolving inflammation in patients with RA, and will likely extend our understanding of the mechanisms of action of currently used therapeutics.

Methods

Synovial fluid (SF) mononuclear cells were obtained from patients with active early RA (<1 year; fulfilling 2010 ACR/EULAR classification criteria). Cryopreserved SFMCs were cultured for 48hr in the presence of 10 ng/mL interferon(IFN)γ, 50 ng/mL dexamethasone, 10 μg/mL Infliximab, or diluent. Following culture, cells were immunostained and analysed using a Beckman Coulter CytoFLEX flow cytometer and FlowJo software. SF macrophages were characterised by expression of CD14, CD45, CD68 (Figure 1A), and proportions of CD206+ MerTK+ macrophages measured.

Figure 1.

Synovial fluid CD68+macrophage plasticity in vitro. (A) Gating strategy depicting CD68+ CD45+CD14+ SF macrophage determination. (B) Proportions of CD206 and MerTK-expressing SF macrophages after 48hr culture in the presence of 10 ng/mL IFNγ, 50 ng/mL dexamethasone or 10 µg/mL Infliximab, or absence. Data are representative of 5 individual experiments. Data were analysed by two-way ANOVA followed by Dunnett’s multiple comparison test, *p<0.05.

Results

Prior to culture, the CD68+ macrophage populations present in SF were found to be predominantly CD206-MerTK-. After 48 hours of culture, in the absence of any stimulus, there was an increase in proportions of CD206+MerTK+ macrophages. Treatment with either dexamethasone or anti-TNF (Infliximab) resulted in a further increase in proportions of CD206+ MerTK+, M2-like macrophages. In contrast, culture with IFNγ induced a reduction in this population. Importantly, we found that the generated CD206+MerTK+ macrophages were phenotypically stable in culture following removal of these differentiating agents.

Conclusion

Our findings demonstrate that inflammatory SF cells are indeed able to polarise to regulatory, CD206+MerTK+ macrophages in vitro. The findings provide further mechanistic insights into the basis for the therapeutic benefits of glucocorticoids and TNF inhibitors, as well as providing initial proof-of-concept in the use of regulatory macrophages as a cellular-based therapy or therapeutic target for patients with RA.

References

[1]Alivernini S, MacDonald L, Elmesmari A, et al., Distinct synovial tissue macrophage subsets regulate inflammation and remission in rheumatoid arthritis. Nature Medicine. 2020;26(8):1295-306 10.1038/s41591-020-0939-8.

Disclosure of Interests

None declared

Annual prevalence estimation of lymphatic malformation with a cutaneous component: observational study of a national representative sample of physicians

Background

Lymphatic malformations (LMs) represent a potentially life-threatening, rare disease of the lymphatic system characterized by development of abnormal vessels, outpouchings, or cysts filled with lymphatic fluid. There are three morphologic types of LMs based on the size of the individual cysts: macrocystic (typically > 2 cm), microcystic (generally < 2 cm), and mixed (includes aspects of both). Macrocystic LMs typically exist beneath the skin and often can involve vascular components and/or organs. Microcystic LMs often have a cutaneous component and clinically present with lymphorrhea, bleeding, pain, itching, malodor, and functional deficits. There are no treatments approved by the US Food and Drug Administration (FDA) for either macrocystic or microcystic lymphatic malformations. The totality of the epidemiologic literature for LM is limited to the incidence of the disease among various birth cohorts. This is the first nationally representative study to estimate the national managed prevalence for patients with microcystic LM or combined LM with a cutaneous component annually across physician specialties likely to manage this condition. We conducted a retrospective observational survey of a nationally representative sample of patient-care physicians in the United States most likely to manage lymphatic malformations with a cutaneous component (LMC). Once recruited, target physicians participated via an electronic questionnaire. We weighted study physician self-estimates of the number of LMC patients treated in the past 12 months to reflect the specialists’ corresponding proportion in the national universe. All patient information was anonymous; no personally identifiable information was collected.

Results

Of the 420 physicians who visited the study website, 316 agreed to be screened and to participate (75.2% participation rate). Our survey results indicated the estimated number of unique annually managed LMC patients by target specialists is 79,920 (CI 66,600–93,250). This number corresponds to managed prevalence of 24.1 LMC patients per 100,000 population (CI 19.6/100,000–28.4/100,000).

Conclusions

The study indicates that while rare, LMC affects a substantial number of people in the US (79,920) who are being managed by one or more specialists. By better understanding the prevalence of people living with LMC who require treatment, efforts to both increase disease awareness and to identify underserved populations in need of potential new treatments can be better focused.

The impact of removing former drinkers from genome-wide association studies of AUDIT-C

BACKGROUND AND AIMS

The Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) questionnaire screens for harmful drinking using a 12-month timeframe. A score of 0 is assigned to individuals who report abstaining from alcohol in the past year. However, many middle-age individuals reporting current abstinence are former drinkers (FDs). Because FDs may be more genetically prone to harmful alcohol use than lifelong abstainers (LAs) and are often combined with LAs, we evaluated the impact of differentiating them on the identification of genetic association.

DESIGN AND SETTING

The United Kingdom Biobank (UKBB) includes AUDIT-C and alcohol drinker status.

PARTICIPANTS

131 510 Europeans, including 5135 FDs.

MEASUREMENTS

We compared three genome-wide association (GWAS) analyses to explore the effects of removing FDs: the full AUDIT-C data, AUDIT-C data without FDs, and data from a random sample numerically matched to the data without FDs. Because prior studies show a consistent association of the ADH1B polymorphism rs1229984 with both alcohol consumption and alcohol use disorder, we compared allele frequencies for rs1229984 stratified by AUDIT-C value and FD versus LA status. Additionally, we calculated polygenic risk scores (PRS) of related diseases.

FINDINGS

The rs1229984 allele frequencies among FDs were numerically comparable to those with high AUDIT-C scores and very different from those of LAs. Removing FDs from GWAS yielded a stronger association with rs1229984 (P value after removal: 1.9 × 10^-70 vs 1.7 × 10^-65 and 2.5 × 10^-62 ), more statistically significant single nucleotide polymorphisms (SNPs) (after removal: 11 vs 9 and 8), and genomic loci (after removal: 11 vs 9 and 7). Additional independent SNPs were identified after removal of FDs: rs2817866 (PTGER3), rs7105867 (ANO3), and rs17601612 (DRD2). For PRS of alcohol use disorder and major depressive disorder, there are statistically significant differences between FDs and LAs.

CONCLUSIONS

Differentiating between former drinkers and lifelong abstainers can improve Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) genome-wide association results.

Case contamination in electronic health records based case-control studies

Clinically relevant information from electronic health records (EHRs) permits derivation of a rich collection of phenotypes. Unlike traditionally designed studies where scientific hypotheses are specified a priori before data collection, the true phenotype status of any given individual in EHR-based studies is not directly available. Structured and unstructured data elements need to be queried through preconstructed rules to identify case and control groups. A sufficient number of controls can usually be identified with high accuracy by making the selection criteria stringent. But more relaxed criteria are often necessary for more thorough identification of cases to ensure achievable statistical power. The resulting pool of candidate cases consists of genuine cases contaminated with noncase patients who do not satisfy the control definition. The presence of patients who are neither true cases nor controls among the identified cases is a unique challenge in EHR-based case-control studies. Ignoring case contamination would lead to biased estimation of odds ratio association parameters. We propose an estimating equation approach to bias correction, study its large sample property, and evaluate its performance through extensive simulation studies and an application to a pilot study of aortic stenosis in the Penn medicine EHR. Our method holds the promise of facilitating more efficient EHR studies by accommodating enlarged albeit contaminated case pools.

Circulating and tissue matricellular RNA and protein expression in calcific aortic valve disease

Aortic valve sclerosis is a highly prevalent, poorly characterized asymptomatic manifestation of calcific aortic valve disease and may represent a therapeutic target for disease mitigation. Human aortic valve cusps and blood were obtained from 333 patients undergoing cardiac surgery (n = 236 for severe aortic stenosis, n = 35 for asymptomatic aortic valve sclerosis, n = 62 for no valvular disease), and a multiplex assay was used to evaluate protein expression across the spectrum of calcific aortic valve disease. A subset of six valvular tissue samples (n = 3 for asymptomatic aortic valve sclerosis, n = 3 for severe aortic stenosis) was used to create RNA sequencing profiles, which were subsequently organized into clinically relevant gene modules. RNA sequencing identified 182 protein-encoding, differentially expressed genes in aortic valve sclerosis vs. aortic stenosis; 85% and 89% of expressed genes overlapped in aortic stenosis and aortic valve sclerosis, respectively, which decreased to 55% and 84% when we targeted highly expressed genes. Bioinformatic analyses identified six differentially expressed genes encoding key extracellular matrix regulators: TBHS2, SPARC, COL1A2, COL1A1, SPP1, and CTGF. Differential expression of key circulating biomarkers of extracellular matrix reorganization was observed in control vs. aortic valve sclerosis (osteopontin), control vs. aortic stenosis (osteoprotegerin), and aortic valve sclerosis vs. aortic stenosis groups (MMP-2), which corresponded to valvular mRNA expression. We demonstrate distinct mRNA and protein expression underlying aortic valve sclerosis and aortic stenosis. We anticipate that extracellular matrix regulators can serve as circulating biomarkers of early calcific aortic valve disease and as novel targets for early disease mitigation, pending prospective clinical investigations.

Differentiating Types of Self-Reported Alcohol Abstinence

We contrast three types of abstinence: quit after alcohol associated problems (Q-AP), quit for other reasons (Q-OR), and lifetime abstainer (LTA). We summarized the characteristics of people living with HIV (PLWH), and matched uninfected individuals, by levels of alcohol use and types of abstinence. We then identified factors that differentiate abstinence and determined whether the association with an alcohol biomarker or a genetic polymorphism is improved by differentiating abstinence. Among abstainers, 34% of PLWH and 38% of uninfected were Q-AP; 53% and 53% were Q-OR; and 12% and 10% were LTA. Logistic regression models found smoking, alcohol, cocaine, and hepatitis C increased odds of Q-AP, whereas smoking and marijuana decreased odds of LTA. Differentiating types of abstinence improved association. Q-APs and LTAs can be readily differentiated by an alcohol biomarker and genetic polymorphism. Differentiating type of abstinence may enhance understanding of alcohol health effects.

Marine plastics threaten giant Atlantic Marine Protected Areas

There has been a recent shift in global perception of plastics in the environment, resulting in a call for greater action. Science and the popular media have highlighted plastic as an increasing stressor [1,2]. Efforts have been made to confer protected status to some remote locations, forming some of the world's largest Marine Protected Areas, including several UK overseas territories. We assessed plastic at these remote Atlantic Marine Protected Areas, surveying the shore, sea surface, water column and seabed, and found drastic changes from 2013-2018. Working from the RRS James Clark Ross at Ascension, St. Helena, Tristan da Cunha, Gough and the Falkland Islands (Figure 1A), we showed that marine debris on beaches has increased more than 10 fold in the past decade. Sea surface plastics have also increased, with in-water plastics occurring at densities of 0.1 items m^-3; plastics on seabeds were observed at ≤ 0.01 items m^-2. For the first time, beach densities of plastics at remote South Atlantic sites approached those at industrialised North Atlantic sites. This increase even occurs hundreds of meters down on seamounts. We also investigated plastic incidence in 2,243 animals (comprising 26 species) across remote South Atlantic oceanic food webs, ranging from plankton to seabirds. We found that plastics had been ingested by primary consumers (zooplankton) to top predators (seabirds) at high rates. These findings suggest that MPA status will not mitigate the threat of plastic proliferation to this rich, unique and threatened biodiversity.

Genomics-First Evaluation of Heart Disease Associated With Titin-Truncating Variants

BACKGROUND

Truncating variants in the Titin gene (TTNtvs) are common in individuals with idiopathic dilated cardiomyopathy (DCM). However, a comprehensive genomics-first evaluation of the impact of TTNtvs in different clinical contexts, and the evaluation of modifiers such as genetic ancestry, has not been performed.

METHODS

We reviewed whole exome sequence data for >71 000 individuals (61 040 from the Geisinger MyCode Community Health Initiative (2007 to present) and 10 273 from the PennMedicine BioBank (2013 to present) to identify anyone with TTNtvs. We further selected individuals with TTNtvs in exons highly expressed in the heart (proportion spliced in [PSI] >0.9). Using linked electronic health records, we evaluated associations of TTNtvs with diagnoses and quantitative echocardiographic measures, including subanalyses for individuals with and without DCM diagnoses. We also reviewed data from the Jackson Heart Study to validate specific analyses for individuals of African ancestry.

RESULTS

Identified with a TTNtv in a highly expressed exon (hiPSI) were 1.2% individuals in PennMedicine BioBank and 0.6% at Geisinger. The presence of a hiPSI TTNtv was associated with increased odds of DCM in individuals of European ancestry (odds ratio [95% CI]: 18.7 [9.1-39.4] {PennMedicine BioBank} and 10.8 [7.0-16.0] {Geisinger}). hiPSI TTNtvs were not associated with DCM in individuals of African ancestry, despite a high DCM prevalence (odds ratio, 1.8 [0.2-13.7]; P=0.57). Among 244 individuals of European ancestry with DCM in PennMedicine BioBank, hiPSI TTNtv carriers had lower left ventricular ejection fraction (β=-12%, P=3×10-7), and increased left ventricular diameter (β=0.65 cm, P=9×10-3). In the Geisinger cohort, hiPSI TTNtv carriers without a cardiomyopathy diagnosis had more atrial fibrillation (odds ratio, 2.4 [1.6-3.6]) and heart failure (odds ratio, 3.8 [2.4-6.0]), and lower left ventricular ejection fraction (β=-3.4%, P=1×10-7).

CONCLUSIONS

Individuals of European ancestry with hiPSI TTNtv have an abnormal cardiac phenotype characterized by lower left ventricular ejection fraction, irrespective of the clinical manifestation of cardiomyopathy. Associations with arrhythmias, including atrial fibrillation, were observed even when controlling for cardiomyopathy diagnosis. In contrast, no association between hiPSI TTNtvs and DCM was discerned among individuals of African ancestry. Given these findings, clinical identification of hiPSI TTNtv carriers may alter clinical management strategies.

Genetic inactivation of ANGPTL4 improves glucose homeostasis and is associated with reduced risk of diabetes

Angiopoietin-like 4 (ANGPTL4) is an endogenous inhibitor of lipoprotein lipase that modulates lipid levels, coronary atherosclerosis risk, and nutrient partitioning. We hypothesize that loss of ANGPTL4 function might improve glucose homeostasis and decrease risk of type 2 diabetes (T2D). We investigate protein-altering variants in ANGPTL4 among 58,124 participants in the DiscovEHR human genetics study, with follow-up studies in 82,766 T2D cases and 498,761 controls. Carriers of p.E40K, a variant that abolishes ANGPTL4 ability to inhibit lipoprotein lipase, have lower odds of T2D (odds ratio 0.89, 95% confidence interval 0.85–0.92, p = 6.3 × 10⁻¹⁰), lower fasting glucose, and greater insulin sensitivity. Predicted loss-of-function variants are associated with lower odds of T2D among 32,015 cases and 84,006 controls (odds ratio 0.71, 95% confidence interval 0.49–0.99, p = 0.041). Functional studies in Angptl4-deficient mice confirm improved insulin sensitivity and glucose homeostasis. In conclusion, genetic inactivation of ANGPTL4 is associated with improved glucose homeostasis and reduced risk of T2D.

Genetic variation in ANGPTL4 is associated with lipid traits. Here, the authors find that predicted loss-of-function variants in ANGPTL4 are associated with glucose homeostasis and reduced risk of type 2 diabetes and that Angptl4^−/− mice on a high-fat diet show improved insulin sensitivity.

Abstract 126: Genome Wide Association Study in the Million Veteran Program Identifies a Novel Role for Thrombosis in the Pathogenesis of Peripheral Artery Disease

Introduction: PAD is a leading cause of cardiovascular morbidity and mortality. Previously published GWAS have been limited by small sample sizes and have only identified 3 genome-wide significant (P<5x10 -8 ) risk loci to date.

Hypothesis: DNA sequence variants affecting multiple biological pathways are associated with PAD risk.

Methods: Using electronic health record data, we identified individuals with and without clinical PAD from the 353,323 Million Veteran Program (MVP) participants genotyped on a customized Affymetrix Biobank array. We tested 32 million genotyped and imputed DNA variants for association with clinical PAD separately in participants of European (EUR), African (AFR), and Hispanic (HIS) ancestry using logistic regression models controlling for age, sex and population structure, and then performed trans-ethnic meta-analysis. The results were replicated with data from the UK Biobank.

Results: We identified 31,307 individuals (24,009 EUR, 5,373 AFR, 1,925 HIS) with, and 211,753 individuals without, PAD. Following meta-analysis and replication, there were 19 genome-wide significant risk loci associated with PAD. We replicated a known association at 9p21 (P=4.3 x10 -39 ), and identified several novel loci associated with PAD that were previously known to be associated with atherosclerosis ( LPA , HDAC9 ), diabetes ( TCF7L2 ), lipid levels ( LPL , CELSR2 ), and tobacco use ( CHRNA3 ). We also identified a novel association with PAD for the Factor V Leiden (FVL) mutation (OR 1.20, P=1.6x10 -12 ), which remained significant after controlling for venous thromboembolism (OR 1.10, P=8.7x10 -4 ). Sensitivity analysis demonstrated FVL is associated with increasing risk estimates for PAD severity (claudication OR 1.19, P=0.0012; rest pain OR 1.41, P=0.004; tissue loss OR 1.57, P=7x10 -9 ).

Conclusions: Using the MVP, we assembled the largest reported cohort of individuals with clinical PAD and genetic data worldwide. Our data replicate known causal risk factors and identify a novel association for FVL and its putative role for thrombosis in the development of clinical PAD.

A Protein-Truncating HSD17B13 Variant and Protection from Chronic Liver Disease

BACKGROUND

Elucidation of the genetic factors underlying chronic liver disease may reveal new therapeutic targets.

METHODS

We used exome sequence data and electronic health records from 46,544 participants in the DiscovEHR human genetics study to identify genetic variants associated with serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Variants that were replicated in three additional cohorts (12,527 persons) were evaluated for association with clinical diagnoses of chronic liver disease in DiscovEHR study participants and two independent cohorts (total of 37,173 persons) and with histopathological severity of liver disease in 2391 human liver samples.

RESULTS

A splice variant (rs72613567:TA) in HSD17B13, encoding the hepatic lipid droplet protein hydroxysteroid 17-beta dehydrogenase 13, was associated with reduced levels of ALT (P=4.2×10^-12) and AST (P=6.2×10^-10). Among DiscovEHR study participants, this variant was associated with a reduced risk of alcoholic liver disease (by 42% [95% confidence interval {CI}, 20 to 58] among heterozygotes and by 53% [95% CI, 3 to 77] among homozygotes), nonalcoholic liver disease (by 17% [95% CI, 8 to 25] among heterozygotes and by 30% [95% CI, 13 to 43] among homozygotes), alcoholic cirrhosis (by 42% [95% CI, 14 to 61] among heterozygotes and by 73% [95% CI, 15 to 91] among homozygotes), and nonalcoholic cirrhosis (by 26% [95% CI, 7 to 40] among heterozygotes and by 49% [95% CI, 15 to 69] among homozygotes). Associations were confirmed in two independent cohorts. The rs72613567:TA variant was associated with a reduced risk of nonalcoholic steatohepatitis, but not steatosis, in human liver samples. The rs72613567:TA variant mitigated liver injury associated with the risk-increasing PNPLA3 p.I148M allele and resulted in an unstable and truncated protein with reduced enzymatic activity.

CONCLUSIONS

A loss-of-function variant in HSD17B13 was associated with a reduced risk of chronic liver disease and of progression from steatosis to steatohepatitis. (Funded by Regeneron Pharmaceuticals and others.).

Genetic and Pharmacologic Inactivation of ANGPTL3 and Cardiovascular Disease

BACKGROUND

Loss-of-function variants in the angiopoietin-like 3 gene (ANGPTL3) have been associated with decreased plasma levels of triglycerides, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol. It is not known whether such variants or therapeutic antagonism of ANGPTL3 are associated with a reduced risk of atherosclerotic cardiovascular disease.

METHODS

We sequenced the exons of ANGPTL3 in 58,335 participants in the DiscovEHR human genetics study. We performed tests of association for loss-of-function variants in ANGPTL3 with lipid levels and with coronary artery disease in 13,102 case patients and 40,430 controls from the DiscovEHR study, with follow-up studies involving 23,317 case patients and 107,166 controls from four population studies. We also tested the effects of a human monoclonal antibody, evinacumab, against Angptl3 in dyslipidemic mice and against ANGPTL3 in healthy human volunteers with elevated levels of triglycerides or LDL cholesterol.

RESULTS

In the DiscovEHR study, participants with heterozygous loss-of-function variants in ANGPTL3 had significantly lower serum levels of triglycerides, HDL cholesterol, and LDL cholesterol than participants without these variants. Loss-of-function variants were found in 0.33% of case patients with coronary artery disease and in 0.45% of controls (adjusted odds ratio, 0.59; 95% confidence interval, 0.41 to 0.85; P=0.004). These results were confirmed in the follow-up studies. In dyslipidemic mice, inhibition of Angptl3 with evinacumab resulted in a greater decrease in atherosclerotic lesion area and necrotic content than a control antibody. In humans, evinacumab caused a dose-dependent placebo-adjusted reduction in fasting triglyceride levels of up to 76% and LDL cholesterol levels of up to 23%.

CONCLUSIONS

Genetic and therapeutic antagonism of ANGPTL3 in humans and of Angptl3 in mice was associated with decreased levels of all three major lipid fractions and decreased odds of atherosclerotic cardiovascular disease. (Funded by Regeneron Pharmaceuticals and others; ClinicalTrials.gov number, NCT01749878 .).

Abstract 122: Supervised Exercise Therapy for Claudication Modulates Global Profiles of Plasma Lipid Mediators

Background: Lipid mediators are complex molecules that demonstrate an association to inflammatory states including atherosclerotic vascular disease. Peripheral artery disease (PAD) is an atherosclerotic disease of the distal aorta and lower extremity arteries. Supervised walking therapy (SWT) is the mainstay of treatment for PAD and is hypothesized to improve claudication by suppressing inflammatory activation.

Objectives: We sought to examine how lipid mediators were impacted by treadmill testing in PAD, and to identify lipid mediators that were altered by SWT.

Methods: Plasma samples were collected before and after Gardner treadmill testing (GTT) in individuals with PAD; participants underwent 12 weeks of SWT and were retested. Lipid mediators were isolated using Ostro Sample Preparation Plates (Waters; Milford, MA) and quantified by UPLC-MS/MS.

Results: Thirty-six participants had complete sets of plasma for analysis. The median age was 67 years (IQR: 62 - 71); there were 55 men (73%) and the median ABI was 0.64 (IQR: 0.55 - 0.76). The median peak walking time prior to SWT was 7.4 min (IQR: 4.8 - 10.3 min), which increased to 11.9 min (IQR: 8.4 - 17.1) after SWT (p < 10 -4 ). Discriminant analysis showed clear separation of pre- and post- GTT and pre- and post- SWT samples based on global lipid profiles (Figure 1). Cluster analysis demonstrated 13 distinct clusters of lipid mediators; those clusters containing carbon and arachidonic acid epoxides, and vicinal diols were significantly (FDR <5%) impacted by the interaction between SWT and GTT.

Conclusions: Lipid mediator profiles manifested unique response patterns to treadmill testing and were modified by supervised walking therapy. These data suggest that lipid mediators play an active role in the biology underlying improvements in lower extremity symptoms associated with SWT and may offer a novel target for therapeutic manipulation.

Abstract 233: Genetic Evidence for Overlap in the Pathogenesis of Peripheral Artery Disease and Coronary Artery Disease

Introduction: Peripheral artery disease (PAD) is thought to share atherosclerotic biologic mechanisms and traditional risk factors with coronary artery disease (CAD). Although significant progress has been made in identifying genetic contributors to CAD, genetic factors underlying PAD remain largely uncharacterized. The aim of our study was to evaluate the shared genetic architecture between PAD and CAD.

Hypothesis: DNA sequence variants associated with CAD risk are also associated with PAD.

Methods: We analyzed the electronic health records from 239,621 U.S. Veterans of European ancestry with available imputed genetic data from the VA Million Veteran Program. Within this cohort we identified 16,364 participants with PAD, and 67,636 with CAD. We constructed additive weighted genetic risk scores (GRS) of 57 DNA sequence variants previously associated with CAD at genome-wide significance. We standardized the GRS to have a mean of zero and standard deviation (SD) of 1, and assessed the strength of its association with PAD through logistic regression. Models were adjusted for age, sex, and 7 principal components of ancestry. In a mediation analysis, we then included CAD status in the model to examine if these genetic associations remained significant after accounting for a CAD diagnosis.

Results: The CAD GRS was significantly associated with clinical CAD [OR = 1.22 per SD increase in GRS, (95%CI: 1.21 -1.23, Z-Score = 44.5, P < 2 x10 -16 )]. The CAD GRS was also significantly associated with PAD [OR = 1.12 per SD increase in GRS, (95%CI: 1.10-1.14, Z-Score = 14.5, P < 2x10 -16 )]. This magnitude of association was attenuated when further adjusting for CAD in the regression model but remained strongly significant [OR = 1.05 per SD increase in GRS, (95%CI: 1.03-1.07, Z-Score = 6.2, P = 5.6x10 -10 )].

Conclusions: In the largest single cohort of CAD and PAD cases worldwide, we found that a genetic risk score of DNA sequence variants associated with risk for CAD are also associated with risk of PAD, even after accounting for the presence of coronary atherosclerosis. These data suggest significant overlap in the mechanisms underlying development of atherosclerosis within both the peripheral and coronary arterial beds.

Biomarkers of Calcific Aortic Valve Disease

Calcific aortic valve disease (CAVD) is a highly prevalent cardiovascular disorder accounting for a rising economic and social burden on aging populations. In spite of continuing study on the pathophysiology of disease, there remain no medical therapies to prevent the progression of CAVD. The discovery of biomarkers represents a potentially complementary approach in stratifying risk and timing of intervention in CAVD and has the advantage of providing insight into causal factors for the disease. Biomarkers have been studied extensively in atherosclerotic cardiovascular disease, with success as additive for clinical and scientific purposes. Similar research in CAVD is less robust; however, the available studies of biomarkers in CAVD show promise for enhanced clinical decision making and identification of causal factors for the disease. This comprehensive review summarizes available established and novel biomarkers in CAVD, their contributions toward an understanding of pathophysiology, their potential clinical utility, and provides an outline to direct future research in the field.

Abstract P1-16-04: First-line chemotherapy for breast cancer patients by site of care (SOC): Treatment patterns, cost and quality indicators

Background: Previous studies found differences in treatment patterns and costs by SOC for first-line chemotherapy treatment for both early stage and metastatic breast cancer (esBC and mBC) in commercial populations. This study extends the research to a predominantly Medicare population comparing chemotherapy treatment patterns, cost and quality of care in physician office (PO) and hospital outpatient (HO) centers.

Methods: First-line chemotherapy or biologic therapy for esBC and mBC patients was compared by SOC. Patients initiating infusion therapy in 2008–2012 were identified in Humana medical claims data. First-line length of therapy (LOT) in days and number of infusions (NI) were calculated. SOC cohort (HO vs PO) was based on where the patient received ≥90% of their infusions. Total healthcare costs based on medical and pharmacy claims were assessed. Differences in quality indicators, use of infusions or hospitalizations 30 days prior to death were evaluated. SOC differences were assessed using X2, T-tests and Wilcoxon Rank Sum (Wil) tests. P-values are for X2 and Wil tests. Cost-related results are from generalized linear models adjusted for age, sex, comorbidity and geographic region. LOT and NI are presented as median (IQR).

Results: A total of 2,784 esBC patients (73% PO and 27% HO) and 1,602 mBC patients (64% PO and 36% HO) were identified. Most patients (67%) were Medicare beneficiaries. Mean comorbidity index was similar by SOC for esBC patients (PO 4.2, HO 4.1, p=0.3308) but higher in HO for mBC patients (PO 7.5, HO 7.9, p=0.0003). LOT in days for esBC was greater in the PO for anthracycline-based therapy, PO 64(43-72), HO 47(43-64), p=0.0420 and taxane-based therapy, PO 64(64-106), HO 64(64-76), p=0.0005. NI for esBC was greater in the PO for patients on biologic and cytotoxic therapy, PO 21(17-29), HO 18(16-25), p=0.038 and taxane–based therapy PO 4(4-6), HO 4(4-4), p=0.0005.

No difference in LOT by SOC was seen for mBC patients; however, patients on taxane-based therapy had a greater NI at the PO 6(4-12) vs HO 5.5(4-9), p=0.0225.

Total healthcare costs were higher in the HO vs PO setting for esBC and mBC patients. Costs were 22% higher in the HO $51,191 vs PO $41,943, p&lt;0.0001 for esBC patients and 17% higher in the HO $58,105 vs PO $49,591, p&lt;0.0001 for mBC patients.

There were no statistically significant differences in use of infusions or hospitalizations 30 days prior to death among Medicare patients. Among 223 esBC and 369 mBC Medicare patients who died, use of infusions prior to death was 24% for HO and 16% for PO among esBC, p=0.2357 and 23% for HO and 26% for PO among mBC, p=0.5319. Hospitalizations prior to death were 59% for HO and 59% for PO for esBC, p=0.9940 and 60% for HO and 55% for PO for mBC, p=0.3105.

Conclusion: Differences by site of care, particularly in healthcare costs, were found in a mostly Medicare population of esBC and mBC patients. Patients in the HO setting had shorter length of therapy and fewer infusions, but had higher total healthcare costs than those in the PO setting. Quality indicators, infusions and hospitalizations prior to death were similar by site of care. Future research will focus on other quality indicators and patient satisfaction.

Citation Format: Masaquel A, Hopson S, Casebeer A, Drzayich-Jankus D, Tao Z, Stemkowski S, Howe A, Patton J, Small A, Barnett B. First-line chemotherapy for breast cancer patients by site of care (SOC): Treatment patterns, cost and quality indicators. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-16-04.

The relationship of sex role to physical and psychological health

This study examined the relationship of sex-role typology, medical and psychiatric symptomatology, and personality functioning in adolescents. Seventy-nine males and 101 females with an average age of 18.3 were administered the Bem Sex Role Inventory (BSRI), Offer Self Image Questionnaire (OSIQ), Self Rating Depression Scale (SRDS), and Cornell Medical Index (CMI). In comparison to males, females reported significantly more medical and psychiatric symptomatology, including depression. Females were also found to have more concern and empathy for others and a better developed superego. They reported greater involvement in making future plans and were more conservative in their sexual attitudes. Sex-role typology yielded no significant differences on the medical and psychiatric scales, but consistent differences were found on the OSIQ, a measure of adolescent personality functioning. In general, the results indicated that androgynous teenagers in every case differed from the undifferentiated ones, with the masculine and feminine groups occupying a mid-position. Androgynous individuals always showed a more favorable adjustment. Undifferentiated individuals had a poorer defensive structure, less adequate coping mechanisms and affective integration, more confusion about body boundaries, and more difficulty in object relations. Androgynous individuals, in short, possessed adaptive capabilities and resources, such as effective coping techniques, emotional integration, communication skills, and a well-defined self-concept (i.e., ego strength and a high level of psychological integration). Since these results were obtained on a measure constructed solely to assess adolescent functioning, it seems possible to screen and identify adolescents who may be entering adulthood lacking the emotional, social, and occupational capacity to function in an optimal fashion.

An evaluation of selected methods for the decontamination of cattle hides prior to skinning

The effectiveness of different decontamination treatments in reducing microbial loads on cattle hides was assessed. The 10-s hide treatments were conducted using a wet-and-dry vacuum cleaner filled with one of the liquids (heated to 50 °C) indicated below, followed or not by 10-min drying in the air. Also, the hide was clipped, followed or not by 10-s singeing using a hand-held blowtorch. Before and after each decontamination treatment, the hide was sampled (100 cm(2) areas) by a sponge-swabbing method to compare the total viable counts of bacteria (TVC). The largest bacterial reduction (P<0.001; 2.31log(10) cfu/cm(2)) was achieved by singeing of previously clipped hide. Treatment of hide with a food industry sanitizer solution (10% Betane Plus) resulted in significant reductions of 1.80 (P<0.001) and 1.98log(10) cfu/cm(2) (P<0.001) without and with subsequent drying, respectively. Treatment of hide with a food industry disinfectant (P3-Topactive DES) significantly reduced TVC by 0.97 (P<0.001) and 1.18log(10) cfu/cm(2) (P<0.001) without and with subsequent drying, respectively. Treatments of hide with water alone or with a food-safe detergent solution (Formula 963B), or hide clipping alone, did not produce significant decontamination effects. Since hide contamination is associated with microbial contamination of the carcasses, the results indicate that post-killing/pre-skinning hide decontamination (used alone, or in combination with carcass decontamination) has a potential to improve microbial meat safety. Nevertheless, further research is required to optimise the efficacy of these treatments in the reduction of specific pathogens under commercial conditions.

Takotsubo cardiomyopathy: an Australian single centre experience with medium term follow up

BACKGROUND

Takotsubo cardiomyopathy (TC) is increasingly recognised in patients presenting with features of acute coronary syndrome. We present a single centre experience of TC with medium term follow up.

METHODS

Fifty-two consecutive patients presenting with a diagnosis of TC were included. The clinical presentation, complications, baseline and follow-up echocardiograms and cardiac magnetic resonance imaging were analysed.

RESULTS

Fifty-one patients were female. A stressful event preceded presentation in 37 (71%) patients. Chest pain was the most common symptom (83%). Two patients presented with an out-of-hospital cardiac arrest. ST segment elevation (40%) and global T wave inversion (44%) were the most frequent electrocardiogram changes. Left ventricular assessment demonstrated typical apical ballooning in 41 patients and 11 patients demonstrated the mid-wall variant. In-hospital complications occurred in 11 patients (21%) and included acute pulmonary oedema (n = 2), cardiogenic shock (n = 5); two of whom had a significant left ventricular outflow gradient, atrial fibrillation (n = 1), left ventricular thrombus (n = 2) and a cerebrovascular event (n = 2). Left ventricular function at presentation and follow up was compared in 40 patients. The mean ejection fraction in this group at presentation was 47% (20-70%) compared with that at follow up of 63% (44-76%). There were no significant complications or recurrences at follow up.

CONCLUSIONS

While TC is a reversible condition with low rates of complications and recurrence at follow up it is, as demonstrated in our cohort, associated with significant in-hospital morbidity in a proportion of patients.

Presence of Salmonella in the red meat abattoir lairage after routine cleansing and disinfection and on carcasses

Foodborne pathogens, such as Salmonella, may remain in abattoir lairages after cleansing and pose a risk of transfer and contamination from one processing day to the next. These organisms may be transferred to the outer surface of animals held in lairage facilities, and the skin or hide may be a significant source of microbial contamination on the red meat carcasses subsequently produced. Sponge samples were taken from various sites in the lairage (n = 556), and single-pass sponge samples were taken from one side of red meat carcasses (n = 1,050) at five commercial abattoirs in Southwest England and tested for the presence of Salmonella. Of these, 6.5% of lairage samples were positive, containing estimated numbers of up to 10(4) Salmonella organisms per sampled area (50 by 50 cm). Salmonella was found on 9.6% of 240 lamb carcasses, 12.7% of 330 beef carcasses, 31% of 70 pig carcasses, 20% of 80 calf carcasses younger than 14 days of age, and none of 330 cull cow and bull carcasses. Subtyping divided the 137 isolates into seven serogroups and three pulsed-field gel electrophoresis clusters, and sensitivity testing against a bank of 16 antimicrobials indicated that 47 isolates had resistance to one or more antimicrobial agents. These results indicate that Salmonella contamination can persist in the lairage environment from one processing day to the next and that Salmonella is present on red meat carcasses, although the implications of residual lairage contamination on carcass meat microbiology are not clear from this study. Abattoir owners should take steps to reduce the level of contamination in their premises to prevent contamination from being carried over from one processing day to the next.

Spread of marker bacteria from the hides of cattle in a simulated livestock market and at an abattoir

The spread of microbial contamination on the hides of beef was investigated at two stages in the meat chain: (i) in a simulated livestock market ("the market") using 33 animals, and (ii) in the unloading-to-skinning area of a commercial abattoir using 18 animals. At both stages, harmless bacterial markers (nalidixic acid-resistant Escherichia coli K-12; rifampicin- and nalidixic acid-resistant Pseudomonas fluorescens; and a tetracycline-resistant E. coli) were inoculated on the hides of a small number of selected animals, and their transfer to other animals and the environment was examined. At the market, the initial prevalence of animals positive for the hide markers (9.1% in each phase) introduced in the presale pen, sale ring, and postsale pen changed to 39.4, 15.1, and 54.5%, respectively, by the end of the market process. In addition, widespread contamination of the market environment with the hide markers was observed. At the abattoir, the initial prevalence of animals positive for the hide marker (11.1%) inoculated at unloading increased to 100% (hide before skinning) and 88.8% (skinned carcass). In addition, another marker inoculated on environmental surfaces in lairage pens, races, and stunning box was detected on 83.3% (hide before skinning) and 88.8% (skinned carcass). These results, although obtained with a relatively small number of animals, demonstrate that both the livestock market process and the unloading-to-skinning process at abattoirs can facilitate the extensive spread of microbial contamination on hides not just within, but also between, batches of animals.