Abstract 204: Prioritizing Genome-Wide Association Study Lipid Loci With Global Gene Networks

Large genome-wide association studies (GWAS) conducted in humans by the Global Lipids Genetics Consortium (GLGC) have identified more than 150 genome-wide significant loci that are associated with variation in plasma lipid levels (cholesterol, LDL/HDL-cholesterol, and triglycerides). Some loci contain genes with well-described roles in lipid metabolism, such as CETP , LDLR , and APOB ; however, for many genome-wide significant loci, there is no clear causal gene. To test the hypothesis that lipid genes in the liver are co-regulated, we constructed global co-expression gene networks from genome-wide gene expression data obtained from the livers of multiple independent mouse genetic crosses. All together, we constructed global gene networks from eight distinct studies, representing more than 800 unique mice of diverse genetic backgrounds. For all studies analyzed, we identified a module (or sub-network) of genes that is significantly enriched (p<1x10 -15 ) functionally for cholesterol biosynthesis and metabolism genes. This module ranges in size from 70 to 824 genes across the eight studies and contains all genes involved in the cholesterol biosynthesis pathway ( Acat2, Hmgcs2, Hmgcr, Lss, Sc5d, etc. ). This module also contains many genes involved in the regulation of cholesterol metabolism, such as Ldlr , Pcsk9 , and Insig1 . Because of the significant enrichment of cholesterol genes in this module, we have begun to cross-reference all genes in the module against the GLGC lipid GWAS data. Through this analysis, we have identified genes of unknown function that are clearly located within genome-wide significant lipid loci as well as sub-threshold (suggestive significant) lipid loci. Among the genes we identified was Sestrin1 , which was located within a clear sub-threshold locus associated with plasma cholesterol (rs12206606; p=1.4 x 10 -5 ). In conclusion, our studies provide a framework to identify causal genes within reported lipid GWAS loci as well as to identify novel sub-threshold loci associated with variations in lipids among humans. We illustrate the approach by identifying Sestrin1 within a sub-threshold locus associated with plasma cholesterol levels and show that Sestrin1 is transcriptionally regulated in the liver by dietary cholesterol.

Cancer Mutations Targeting TNFRSF14 alter Microenvironment Checkpoint Interactions to Limit Tumor Clearance by Cytotoxic Cells

The roles of many non-oncogenic mutations in cancer may influence tumor growth, survival, or how tumors interact with their surroundings. Here we characterize the functional relevance of missense mutations within the gene encoding the tumor necrosis receptor family member HVEM (TNFRSF14), a locus frequently targeted within human lymphoma and other cancers. We find that point mutations identified in human lymphoma were localized to the extracellular domain and specifically target ligand binding, resulting in preferential loss of CD160 and BTLA interactions compared to LIGHT (TNFSF14). Missense mutations were associated with alterations in cytotoxic effector cell signatures within tumor biopsies, while deletion mutations were associated with changes in myeloid cell signatures. Finally, we find that mutated HVEM proteins retained the capacity to inhibit T cell signaling through BTLA, while reducing costimulation of cytolysis in NK cells through CD160. Together, these data provide evidence for how immune selective pressures may drive mutation of TNFRSF14 resulting in greater tumor fitness.

Abstract A73: Knowledge of precision medicine among African-Americans: A pilot study

Precision Medicine has the potential to improve clinical outcomes and minimize risk and adverse effects of treatments and medication. During President Obama's State of the Union address in 2015, he highlighted the promise of precision medicine and announced the Precision Medicine Initiative (PMI). Part of the PMI is the creation of the Precision Medicine Initiative Cohort. This program aims to recruit at least one million Americans to contribute their data over the span of many years to improve health outcomes, understand the impact of new treatments, and accelerate a new era of data-drive and precise preventive care and treatment. Precision medicine could address multiple issues we face, including cancer treatment and address health disparities in health disparity populations. However, little is known about health disparities populations' knowledge level of precision medicine. A pilot study was conducted to investigate whether self-identified Blacks/African-Americans could define the following terms in their own words: precision medicine, personalized medicine, and pharmacogenomics. Self-administered surveys were handed out at health fairs, barbershops, salons, and churches throughout the state of Florida and 132 (n=132) individuals responded. Participants were asked to provide demographic data, note whether or not they have heard a particular PMI concept, define the concept in their own word (if familiar with the term), and whether or not precision medicine can improve cancer care and treatment. Sixty-two percent of individuals had a college degree and 71% of respondents were employed. 81% of individuals (n=107) have never heard of pharmacogenomics, 55% (n=73) have never heard of personalized medicine, and 77% (n=102) have never heard of precision medicine. 9% (n=12) believe that precision medicine will improve cancer care and treatment, but n=72 marked “I don't know.” Critical to PMI is the enrollment of citizens into the research cohort. Increasing the diversity of the national research cohort is imperative as there are high levels of health disparities and unnecessary medical spending in our health care setting. Yet, if individuals are not aware of precision medicine and corresponding precision medicine concepts, they are unlikely to volunteer and participate in the PMI. The lack of diversity within clinical trials has caused issues and concerns within the medical community. By ensuring that the PMI cohort is inclusive, diverse, and representative of the American population, its ability to address health disparities will be more effective, efficient, and ethical.

Citation Format: Jennifer Nguyen, Christina Redwine, Lauren Gilbert, Folakemi Odedina. Knowledge of precision medicine among African-Americans: A pilot study. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr A73.

NEUDOSE: A CubeSat Mission for Dosimetry of Charged Particles and Neutrons in Low-Earth Orbit

During space missions, astronauts are exposed to a stream of energetic and highly ionizing radiation particles that can suppress immune system function, increase cancer risks and even induce acute radiation syndrome if the exposure is large enough. As human exploration goals shift from missions in low-Earth orbit (LEO) to long-duration interplanetary missions, radiation protection remains one of the key technological issues that must be resolved. In this work, we introduce the NEUtron DOSimetry & Exploration (NEUDOSE) CubeSat mission, which will provide new measurements of dose and space radiation quality factors to improve the accuracy of cancer risk projections for current and future space missions. The primary objective of the NEUDOSE CubeSat is to map the in situ lineal energy spectra produced by charged particles and neutrons in LEO where most of the preparatory activities for future interplanetary missions are currently taking place. To perform these measurements, the NEUDOSE CubeSat is equipped with the Charged & Neutral Particle Tissue Equivalent Proportional Counter (CNP-TEPC), an advanced radiation monitoring instrument that uses active coincidence techniques to separate the interactions of charged particles and neutrons in real time. The NEUDOSE CubeSat, currently under development at McMaster University, provides a modern approach to test the CNP-TEPC instrument directly in the unique environment of outer space while simultaneously collecting new georeferenced lineal energy spectra of the radiation environment in LEO.

The state of point-of-care ultrasonography use and training in neonatal-perinatal medicine and pediatric critical care medicine fellowship programs

OBJECTIVE

The current state of point-of-care ultrasonography (POCUS) use and education in neonatal-perinatal medicine (NPM) and pediatric critical care medicine (PCCM) is unknown. Our aim was to quantify POCUS use, training and perceptions regarding education and barriers among the United States NPM and PCCM fellowship programs.

STUDY DESIGN

A 14-question survey was emailed to the fellowship directors of all the United States NPM and PCCM fellowship programs.

RESULTS

The response rate was 55% (52/95) and 59% (39/66) for NPM and PCCM programs, respectively. Over 90% of respondents in both groups believe that fellows and attendings should receive POCUS training. PCCM programs, compared with NPM, had greater access to POCUS machines (97% vs 63%, P<0.001), and more often used POCUS for diagnoses and management (76% vs 29%, P<0.001) and procedural guidance (95% vs 37%, P<0.001). The most common indications were cardiac/hemodynamics, pulmonary pathology and vascular access in both specialties. PCCM reported more training to fellows (90% vs 29%, P<0.001). Both group perceived lack of time to learn, lack of equipment/funds, liability concerns, lack of personnel to train physicians and cardiology/radiology resistance as significant barriers to POCUS implementation.

CONCLUSIONS

Both NPM and PCCM fellowship programs believe in the benefits of POCUS and that their physicians should receive the necessary training. Compared with PCCM, NPM fellowships programs have less access to POCUS machines and less frequently use POCUS and train their fellows and attendings. There remain significant barriers to utilization of POCUS, especially in NPM.

Determinants of Treatment Delays among Underserved Hispanics with Lung and Head and Neck Cancers

Background

Evidence is lacking to explain the reasons why treatment is delayed among disadvantaged Hispanic patients diagnosed with lung and head and neck cancers. Data indicate that treatment delays beyond 46 days increase the risk of death for individuals with these cancers.

Methods

A mixed-methods design was used to explore determinants of treatment delays by analyzing data from the medical records of 40 Hispanic patients and data from interviews with 29 Hispanic patients, care-givers, health care professionals, and patient navigators from a safety-net hospital.

Results

Of the 40 Hispanic patients, 35% initiated treatment 46 days or more after being diagnosed, but women experienced longer delays than men (average of 48 days). Women with few comorbid diseases (≤ 4) were more likely to experience treatment delays. Institutional-related determinants at publicly funded hospitals appear to delay treatment for patients at the safety-net hospital, and patient-related determinants common to underserved patients (eg, no health insurance coverage) are likely to further contribute to these delays.

Conclusions

Delayed treatment is associated with poor outcomes and low rates of survival in patients with lung and head and neck cancers. Therefore, action should be taken to improve the time between diagnosis and the initiation of treatment for disadvantaged Hispanic patients.

Assessing the Utilization of Total Ankle Replacement in the US

Category:

Ankle Arthritis

Introduction/Purpose:

While total ankle arthroplasty has been shown to be a cost-effective procedure relative to conservative management and ankle arthrodesis, implant costs and complications have the potential to increase the overall financial burden of performing TAR. The purpose of this investigation is to analyze the overall cost and utilization of total ankle arthroplasty.

Methods:

Our analytical sample consisted of Inpatient Prospective Payment System hospitals from 2011 and 2012 Medicare claims data and the 2011-2012 Medicare Inpatient Limited Data Sets. Outcome variables of interest were the likelihood of a hospital performing TAR and the volume of TAR cases, conditional on a hospital having performed at least 1 TAR in a year. Data from the 2010 Cost Report and from Medicare inpatient claims were utilized to compute average margins for TAR cases and overall hospital margins. TAR cost was calculated based upon the all payer cost-to-charge ratio for each hospital provided by the Healthcare Cost and Utilization Project. The FY2015 Impact File was used to gather data on hospital-level characteristics, such as bed size, census region, teaching status, and urban/rural location. Hospital ownership data were obtained from the CMS Hospital Compare Database. Nationwide Inpatient Sample (NIS) data was used to generate descriptive statistics on all TAR patients.

Results:

Medicare participants accounted for 47.5% of the overall population of patients. Orthopaedic specialty hospitals are four times more likely to perform TAR than a non-orthopedic specialty hospital. Average implant cost was $13,034, which accounted for approximately 70% of the total all-payer cost. With respect to teaching versus non-teaching hospitals, the average cost per case is $18,331 and $19,303 respectively. Compared to nonprofitable hospitals, profitable hospitals performing TAR in 2011 had lower total costs ($14,425 vs. $19,884) and higher payments ($19,631 vs. $13,640), leading to a difference in profit of approximately $11,000 from TAR surgeries between profitable and nonprofitable hospitals. Approximately, one-third of hospitals were profitable with respect to TAR. No difference was noted with respect to length of stay or number of cases performed between profitable and nonprofitable hospitals.

Conclusion:

There is an overall significant financial burden associated with performing total ankle replacement with many health systems failing to demonstrate profitability despite its increased utilization. Profitable hospitals are more likely to have lower cost per day and prosthesis costs and higher payments compared to nonprofitable hospitals. While additional factors such as improved patient outcomes are driving utilization of TAR, financial barriers exist that can affect utilization of TAR across health systems.

Individualized Education Program Development Among Racially/Ethnically Diverse Children and Adolescents with Health Conditions

Background Black, Hispanic, and low income children bear a greater burden of chronic health conditions compared to wealthier white counterparts. Under federal law, schools provide services to children when their health conditions impair learning. These school services, called individualized education programs (IEPs) can reduce disparities in school outcomes. This paper examines the extent to which children with health conditions have an IEP plan, an important first step in understanding service utilization. Method Andersen's Behavioral Model was used to examine IEP plan presence by using the 2012 National Survey of Children's Health. School aged children (6-17), with at least one health condition (N = 16,496) were examined using multivariable logistic regression analysis to understand predisposing (age, sex, race/ethnicity), enabling (family and neighborhood), and need (health related) factors as predictors of having an IEP plan. Race/ethnicity interaction terms tested for moderating effects of race/ethnicity on the relationship between predisposing, enabling and need factors and having an IEP plan. Results Hispanic children were 93.4 % (OR = .066) less likely and Black children were 87.9 % (OR = .121) less likely to have an IEP plan compared to White children. Black, Hispanic, and Multiracial children were more likely to have an IEP plan if they had more family and neighborhood resources (OR range 1.37-1.62) and greater health needs and health care needs (OR range 1.29-2.57). Conclusion The Behavioral Model was useful in predicting the presence of IEP plans among racially/ethnically diverse children with health conditions as an important step in understanding disparities in healthcare access in schools.

Construct Validity of the eHealth Literacy Scale (eHEALS) Among Two Adult Populations: A Rasch Analysis

BACKGROUND

The Internet has become a ubiquitous venue for information seeking, especially for health information. Public health practitioners have noticed the promise and potential of the Internet, however, little is known about individuals' skills of their eHealth literacy. The eHealth Literacy Scale, eHEALS, was designed to measure perceptions of individuals' eHealth literacy skills.

OBJECTIVE

The objective of the study was to examine the psychometric validity and reliability of the eHEALS with two adult populations using the Rasch Model.

METHODS

A college-aged sample and an Internet-based sample (Amazon's MTurk) were recruited to complete the eHEALS, demographic questions, and a health literacy scale. Using WINSTEPS and SPSS, unidimensionality, item fit, rating scale, item hierarchy, person ability-item match, and reliability were analyzed, compared, and contrasted against each sample and to other samples found in the literature.

RESULTS

An exploratory factor analysis supported unidimensionality in both samples. More than 90% of respondents from both samples fit the model. No items were outright misfitting. Both samples separated into three distinct groups.

CONCLUSIONS

Based on the results, the eHEALS is a reliable and consistent measurement tool for a college sample and an Internet-based sample. As these individuals are most likely to use the Internet as a health resource, it is necessary to learn and know their skills versus perceiving that they can critically and successfully navigate the Internet. Further analyses are necessary to ensure that the eHEALS can serve as a standard eHealth literacy measure for public health.

Targeting the HVEM-BTLA-CD160-LIGHT network in Psoriasis

Genetic studies have identified heritable linkages to psoriasis. However, complete identification of psoriasis susceptibility loci remains elusive. We have identified the HVEM-BTLA-CD160-LIGHT pathway as a critical regulator of innate and adaptive cell function in several autoimmune diseases, and recently in a mouse model of experimental psoriasis. Specifically, we have shown that the inhibitory receptor BTLA regulates the activity of innate γδ T cells, correlating with worsened dermatitis in BTLA-deficient animals, and attenuated disease in animals treated with agonistic BTLA antibodies. Additionally, our data indicates that the TNF receptor protein HVEM activates CD160 receptors in innate cells, promoting inflammatory signaling. More recently we have observed that skin inflammation is also worsened in animals lacking the TNF ligand for HVEM, LIGHT. In order to promote anti-inflammatory activities of HVEM, we sought to develop ligand specific biologics that could selectively engage inhibitory pathways through BTLA. Our initial studies showed that wild-type HVEM-Fc worsens disease. Additionally, we find that LIGHT-specific proteins that block HVEM-LIGHT interactions also worsen disease, consistent with our results in LIGHT-deficient animals, and identifying a unique regulatory role for LIGHT in skin inflammation. Finally, animals treated with proteins specific for BTLA and CD160 show reduced pathology compared to animals treated with wild-type HVEM-Fc. Through our efforts to synthesize ligand specific HVEM biologics, we have shown how select ablation of HVEM ligands can result in both pro- and anti-inflammatory signaling that can be targeted for the development of therapeutics for inflammatory diseases.

Development of perturbation Monte Carlo methods for polarized light transport in a discrete particle scattering model

We present a polarization-sensitive, transport-rigorous perturbation Monte Carlo (pMC) method to model the impact of optical property changes on reflectance measurements within a discrete particle scattering model. The model consists of three log-normally distributed populations of Mie scatterers that approximate biologically relevant cervical tissue properties. Our method provides reflectance estimates for perturbations across wavelength and/or scattering model parameters. We test our pMC model performance by perturbing across number densities and mean particle radii, and compare pMC reflectance estimates with those obtained from conventional Monte Carlo simulations. These tests allow us to explore different factors that control pMC performance and to evaluate the gains in computational efficiency that our pMC method provides.

Examining Plasmodium falciparum and P. vivax clearance subsequent to antimalarial drug treatment in the Myanmar-China border area based on quantitative real-time polymerase chain reaction

BACKGROUND

Recent emergence of artemisinin-resistant P. falciparum has posed a serious hindrance to the elimination of malaria in the Greater Mekong Subregion. Parasite clearance time, a measure of change in peripheral parasitaemia in a sequence of samples taken after treatment, can be used to reflect the susceptibility of parasites or the efficiency of antimalarials. The association of genetic polymorphisms and artemisinin resistance has been documented. This study aims to examine clearance time of P. falciparum and P. vivax parasitemia as well as putative gene mutations associated with residual or recurred parasitemia in Myanmar.

METHODS

A total of 63 P. falciparum and 130 P. vivax samples collected from two internally-displaced populations and one surrounding village were examined for parasitemia changes. At least four samples were taken from each patient, at the first day of diagnosis up to 3 months following the initial treatment. The amount of parasite gene copy number was estimated using quantitative real-time PCR based on a species-specific region of the 18S rRNA gene. For samples that showed residual or recurred parasitemia after treatment, microsatellites were used to identify the 'post-treatment' parasite genotype and compared such with the 'pre-treatment' genotype. Mutations in genes pfcrt, pfmdr1, pfatp6, pfmrp1 and pfK13 that are potentially associated with ACT resistance were examined to identify if mutation is a factor for residual or persistent parasitemia.

RESULTS

Over 30% of the P. falciprium infections showed delayed clearance of parasitemia after 2-3 days of treatment and 9.5% showed recurred parasitemia. Mutations in codon 876 of the pfmrp1 corroborated significance association with slow clearance time. However, no association was observed in the variation in pfmdr1 gene copy number as well as mutations of various codonsinpfatp6, pfcrt, and pfK13 with clearance time. For P. vivax, over 95% of the infections indicated cleared parasitemia at days 2-3 of treatment. Four samples were found to be re-infected with new parasite strains based on microsatellite genotypes after initial treatment.

CONCLUSION

The appearance of P.falciparum infected samples showing delayed clearance or recurred parasitemia after treatment raises concerns on current treatment and ACT drug resistance.

The impact of disease activity and tumour necrosis factor-α inhibitor therapy on cytokine levels in juvenile idiopathic arthritis

The aim of this study was to evaluate prospectively cytokine levels and disease activity in juvenile idiopathic arthritis (JIA) patients treated with and without tumour necrosis factor (TNF)-α inhibitors. TNF-α inhibitor-naive JIA subjects were followed prospectively for 6 months. Cytokine levels of TNF-α, interleukin (IL)-1β, IL-6, IL-8, IL-10 and IL-17 were measured at baseline for JIA subjects and healthy controls (HCs). Cytokine levels were then measured at four time-points after initiation of TNF-α inhibition for anti-TNF-α-treated (anti-TNF) JIA subjects, and at two subsequent time-points for other JIA (non-TNF) subjects. JIA disease activity by Childhood Health Assessment Questionnaire (CHAQ) disability index/pain score and physician joint count/global assessment was recorded. Sixteen anti-TNF, 31 non-TNF and 16 HCs were analysed. Among JIA subjects, those with higher baseline disease activity (subsequent anti-TNFs) had higher baseline TNF-α, IL-6 and IL-8 than those with lower disease activity (non-TNFs) (P < 0·05). TNF-α and IL-10 increased, and IL-6 and IL-8 no longer remained significantly higher after TNF-α inhibitor initiation in anti-TNF subjects. Subgroup analysis of etanercept versus adalimumab-treated subjects showed that TNF-α and IL-17 increased significantly in etanercept but not adalimumab-treated subjects, despite clinical improvement in both groups of subjects. JIA subjects with increased disease activity at baseline had higher serum proinflammatory cytokines. TNF-α inhibition resulted in suppression of IL-6 and IL-8 in parallel with clinical improvement in all anti-TNF-treated subjects, but was also associated with elevated TNF-α and IL-17 in etanercept-treated subjects.