By Gerri Kelly
From Alzheimer's disease and asthma to diabetes and a chemotherapy drug, researchers at Mayo Clinic are tapping the Sangre Por Salud (Spanish for "Blood for Health") Biobank in Arizona, a rich source of biospecimens that expands diversity in medical research.
The Sangre Por Salud Biobank was created in 2013 to expand precision medicine research to Hispanic patients and increase the diversity of the Mayo Clinic Biobank. It is a collaboration of the Center for Individualized Medicine, Mountain Park Health Center in Phoenix and Arizona State University.
Sangre Por Salud houses samples and health information from more than 3,700 people who self-identify as Hispanic or Latino and receive care at Mountain Park. Every sample in the biobank represents a person from the local community who has given consent for their donation to be used for research.
"We are one of the few cohorts of samples from 100% self-identified Latino volunteers," says Elena De Filippis, M.D., Ph.D., an endocrinologist at Mayo Clinic in Arizona and principal investigator of the Sangre Por Salud Biobank.
The biobank includes detailed family history and medical electronic records, genome-wide association studies data, lab results, serum and plasma samples, and DNA samples. Every six months, the biobank receives updates on structured patient data from electronic medical records from the Mountain Park Health Center.
Dr. De Filippis says the biobank provides biostatistical support and eight hours of a dedicated biostatistician to complete feasibility evaluations for research teams.
Investigators in Arizona, Florida and Minnesota shared their current projects addressing health disparities and why they decided to work with Sangre Por Salud.
At Mayo Clinic in Florida, Nilüfer Ertekin-Taner, M.D., Ph.D., a neuroscientist and behavioral neurologist, and Minerva Carrasquillo, Ph.D., a neurogeneticist, conducted a study that searched for genetic variants associated with dementia risk using data from Sangre Por Salud.
They specifically looked at a genetic variant in the APOE gene, involved in making a protein that helps carry cholesterol and other types of fat in the bloodstream. This variant, called APOE4 allele, is known to increase the risk of developing Alzheimer's disease in non-Hispanic white individuals. Other studies have shown the APOE4 allele presents less risk of the disease in Hispanic and African Americans.
The results of their research supports the latter observation, which led them to test the association of other genetic variants located in the APOE gene and variants surrounding this gene to determine if any of these other variants showed an association with decreased risk of Alzheimer’s disease in Hispanic and African Americans.
Dr. Carrasquillo says additional analyses is needed to answer this question.
"We are hopeful that data from the Sangre Por Salud cohort is bringing us closer to understanding the relationship of genetic variants in the APOE gene and the risk of Alzheimer’s disease," she says.
Victor Ortega, M.D., Ph.D., a pulmonary disease specialist and genetic epidemiologist at Mayo Clinic in Arizona, is gearing up a genetic study of asthma that's relevant to Hispanic populations using data from Sangre Por Salud.
Over the past 15 years, Dr. Ortega has focused much of his research in genetic studies for risk of asthma to understand what are the rare genetic determinants of asthma that make it more severe or less responsive to drugs in diverse populations.
"At the same time, only 1% of participants in existing studies are Hispanic, and about 2% are of African descent or from continental Africa," says Dr. Ortega. "That leaves a vast underrepresentation of minorities in genetics research and genomic research in general."
Dr. Ortega says the reason repositories like the Sangre Por Salud are important is because of the push to advance genetic science and to make discoveries to understand the genetic architecture of complex diseases.
Over their lifetimes, U.S. adults have a 40% chance of developing Type 2 diabetes. But if you’re a Hispanic or Latino adult, your chance is more than 50%, and you're likely to develop it at a younger age, according to the Centers for Disease Control and Prevention.
Chandrasagar (Sagar) Dugani, M.D., Ph.D., a hospital internal medicine physician in Minnesota, says there were several factors that made Sangre Por Salud an ideal cohort to study diabetes risk, including its geographic location. Sangre Por Salud is based in metropolitan Phoenix and represents a cohort that has not been well studied.
"This is important because Arizona has one of the highest Hispanic populations in the U.S., yet we have very little information on risk factors for diabetes in this population," says Dr. Dugani.
In the U.S., Hispanic adults have a high burden of diabetes, and the reasons are not completely understood. To address this health problem, Dr. Dugani and his team developed the Hispanic PREDICT Study using data from Sangre Por Salud to understand the role of diet, physical activity and obesity in developing diabetes.
Dr. Dugani has worked with the biobank staff on numerous diabetes studies over the past four years, and says they have consistently provided critical and timely support.
"The biobank has an excellent repository of biosamples that provides a strong platform for biomarkers and genetics research," he says.
Another Minnesota-based researcher is using data from the Sangre Por Salud Biobank for a chemotherapy study. Steven Offer, Ph.D., assistant professor of pharmacology, is a colorectal cancer researcher with the overall goal of providing diagnostic tools to better individualize patient care and identify pathways for further drug development.
In his current study, Dr. Offer is using data from the biobank to identify predictive biomarkers of toxicity risk to the commonly used chemotherapeutic drug 5-fluorouracil (5-FU) in the Hispanic and Latino population.
Although 5-FU is widely used and highly effective for the treatment of various cancers, clinical studies have identified genetic risk factors for severe 5-FU toxicity, and genotype-guided 5-FU dose adjustment has been shown to alleviate the increased toxicity in variant carriers. However, those clinical studies have had limited racial diversity, and, as such, current genetic tests have unknown clinical utility in underrepresented groups.
"We are analyzing data from the biobank samples to identify risk variants for 5-FU toxicity in Hispanic and Latino populations. It is our hope that these data will improve predictive tests and offer greater confidence that the results are relevant to a larger proportion of the population," says Dr. Offer.
"We need cohorts exactly like Sangre Por Salud," says Dr. Ertekin-Taner, director of the Mayo Clinic Genetics of Alzheimer's Disease and Endophenotypes Lab. "One of the gaps in research is the lack of availability of well-characterized cohorts in which deep phenotypes and molecular and biomarker information exist."
Dr. De Filippis and her collaborators are exploring the potential of adding more in-depth genomic data, which hopefully will be available soon. For more information about the Sangre Por Salud Biobank, contact Dr. De Filippis at firstname.lastname@example.org.
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