- Researchers at Vanderbilt University Medical Center (VUMC) and the University of Arizona’s College of Pharmacy successfully used EHR data to create one of the first comprehensive catalogs of diseases to help identify patients at risk for developing certain autoimmune diseases.
The catalog lists diseases associated with variations in human leukocyte antigen (HLA) genes responsible for maintaining the immune system which can help alert healthcare providers to patients at risk for developing autoimmune diseases or antibodies prone to attack their own tissues in response to infection.
Researchers studied nearly 29,000 individuals with DNA samples stored in BioVU, Vanderbilt’s DNA database, as well as 8,400 samples provided by Marshfield Clinic’s Scott Hebbring, PhD, to infer which HLAs would be expressed in each gene.
“To my knowledge no other investigations have made this level of data available to the wider research community,” said repot co-author Jason Karnes, PhD, PharmD, of UA College of Pharmacy.
Setting the study apart from previous research regarding HLA genes is the broadened scope of measurements available to researchers using patient EHRs.
In past studies, researchers have found associations between the HLA system and distinct phenotypes.
However, VUMC and UA researchers conducted a phenome-wide association study (or PheWAS) allowing for the scanning of entire patient phenomes of all health characteristics contained within the EHR.
Genetic samples from the BioVU database were linked to de-identified EHRs to give researchers a comprehensive view of patients with certain autoimmune diseases.
Patient EHRs were then screened to test for the presence of almost 1,400 different phenotypes potentially connected to the HLA genes.
By studying multiple diseases at once, the phenome-wide association study showed that several HLA types affect many diseases in different ways.
"In one fell swoop we essentially replicated decades of research on autoimmune associations with the HLA," said Karnes.
Variations in HLA genes have also been linked to adverse drug reactions and organ transplant rejections.
The strongest HLA association confirmed through the study was Type 1 Diabetes. However, researchers also found evidence for a host of other potential HLA associations relating to multiple sclerosis and cervical cancer.
Presently, the VUMC BioVU database contains over 230,000 DNA samples.
"Just imagine what we'll be able to do with a million people," said senior author and VU biomedical informatics professor Joshua Denny, MD, MS. "That will produce truly comprehensive catalogs of all these kinds of associations across HLA and everything else. The detail with which we'll be able to resolve these questions will be staggering."
According to Denny, the study confirms the power of EHRs to improve and advance understanding, treatment, and prevention of disease.
Evidence suggests individuals with certain HLA variants may generate antibodies attacking their own tissues.
By scanning patient EHRs to detect certain HLA variants, doctors could prevent related autoimmune diseases in high-risk patients by treating infections before resulting antibodies attack the patient’s tissues.
The potential to harness the power of EHR systems and comprehensive medical records for preventive medicine adds another bullet point to the list of benefits to EHR use.
The study was made possible by DNA databases at VUMC and the Marshfield Clinic Personalized Medicine Research Project in Marshfield, Wisconsin.
This study follows previous research also verifying the effectiveness of EHRs to improve patient health outcomes. Researchers at Loyola University Medical Center in March showed hospital EHR use can counteract the weekend effect, a phenomenon in which health outcomes for patients after weekend surgeries are less positive than surgeries during the week.