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DNA testing

The Evolution of PGx: Unraveling the Power of Pharmacogenomics Testing

In the wake of the COVID-19 pandemic, the world witnessed an unprecedented global health crisis that challenged healthcare systems and underscored the importance of personalized and precision medicine.

Amidst the chaos, the role of pharmacogenomics testing, abbreviated as PGx, emerged as a beacon of hope. While PGx has been steadily advancing over the years, the urgent need for molecular testing infrastructure to combat the pandemic helped fast-track its integration into the U.S. healthcare system.

“The PCR test (polymerase chain reaction) has been the gold standard test for diagnosing COVID-19 since authorized for use in February 2020,” said the Cleveland Clinic.

The pandemic not only accelerated the adoption of genomic testing technologies but also highlighted the potential of pharmacogenomics in tailoring treatments and improving patient outcomes.

A research article published in Clinical and Translational Science in 2021 found that:

  • Patients hospitalized with COVID-19 are typically older and have comorbidities. Most people in the general population possess actionable pharmacogenomic variants.

  • 9 in 10 patients hospitalized for COVID-19 had an order for medication with PGx guidance. These medications included those intended to treat COVID-19 symptoms and chronic conditions. PGx medication use and actionable results often co-occur, and using a multi-gene PGx panel would yield 17 opportunities for modifying treatment per 100 patients tests.

  • If institutions use pre-emptive PGx testing or extracted PGx information from research biorepositories, these results would be highly relevant during COVID-19 hospitalization.

Understanding PGx: Combining Pharmacology + Genomics

PGx, short for Pharmacogenomics, is the study of how a person's genetic information influences their response to drugs. This branch of science combines pharmacology, which is the study of drugs, with genomics, the study of genes and their functions.

Pharmacogenomics testing involves analyzing specific genes that affect drug metabolism, efficacy, and toxicity.

“Pharmacogenomic tests look for changes or variants in these genes that may determine whether a medication could be an effective treatment for you or whether you could have side effects to a specific medication,” says the Mayo Clinic.

In simpler terms, each of us possesses a unique genetic blueprint, and these genetic variations can significantly impact how our bodies process medications.

Some individuals might experience enhanced benefits from certain drugs, while others may encounter adverse reactions.

Understanding these genetic variations through PGx testing empowers healthcare professionals to make informed decisions when prescribing medications, ensuring personalized treatment plans tailored to each patient's genetic profile.

Role of Technological Advancements in PGx Evolution

The evolution of PGx would not have been possible without the rapid progress in technology.

Several technological advancements have played a pivotal role in driving the growth of pharmacogenomics testing:

  • Next-Generation Sequencing (NGS): NGS has revolutionized genomics research by allowing scientists to sequence large portions of the human genome more rapidly and cost-effectively than ever before. This technology enables the analysis of numerous genes simultaneously, making it feasible to incorporate PGx testing into routine clinical practice.

  • Real-Time PCR (Polymerase Chain Reaction): Real-time PCR is a powerful technique that allows researchers to amplify and quantify specific DNA sequences. In PGx, real-time PCR is utilized to detect genetic variants associated with drug response quickly and accurately.

  • Microarrays: Microarray technology enables the simultaneous analysis of multiple genetic markers in a patient's DNA. In PGx, microarrays are valuable tools for genotyping and identifying variations in drug-metabolizing enzymes and drug targets.

  • Mass Spectrometry (Mass Spec): Mass spectrometry is an analytical technique used to measure the mass and composition of molecules. In PGx, mass spec plays a vital role in quantifying drug metabolites, enabling precise monitoring of drug levels and responses in patients.

  • Bioinformatics: The immense amount of genetic data generated through NGS requires advanced computational tools to interpret and analyze it effectively. Bioinformatics tools and algorithms help identify crucial genetic variations linked to drug response, enabling clinicians to make accurate treatment decisions.

  • Electronic Health Records (EHRs): The integration of PGx data into electronic health records has streamlined the process of accessing and utilizing genetic information in real time. This ensures that prescribing physicians have immediate access to relevant PGx data when making medication decisions, enhancing patient safety and treatment efficacy.

  • Mobile Health (mHealth) Applications: The rise of mobile health applications has empowered patients to actively engage in their healthcare. Some mHealth apps now offer PGx insights, allowing patients to share their genetic information with healthcare providers and make informed decisions together.

As technology continues to advance, PGx testing will become more accessible, affordable, and seamlessly integrated into routine medical practice.

Cost Effectiveness and PGx Testing

While adopting new medical technologies often raises concerns about cost, PGx testing has demonstrated its cost-effectiveness in the long run.

By reducing the trial-and-error approach to medication prescribing, PGx helps prevent:

  • Adverse drug reactions
  • Hospitalizations
  • Unnecessary treatments.

This not only improves patient outcomes but also reduces healthcare costs associated with ineffective or harmful drugs.

As technology advances and PGx testing becomes more streamlined, the costs are expected to decrease further, making it a financially viable and beneficial addition to the standard of care.

Role of Collaboration in PGx: Vital Role of Pharmacists

Pharmacists play a crucial role in bridging the gap between physicians and laboratory testing in the realm of pharmacogenomics.

As medication experts, pharmacists possess in-depth knowledge of drug interactions and can interpret PGx test results effectively.

They collaborate with physicians to ensure that the prescribed medications align with the patient's genetic profile, optimizing treatment outcomes. Additionally, pharmacists educate patients about the importance of PGx testing, ensuring they understand how it can positively impact their health.

This collaborative effort between pharmacists and physicians is integral to successful PGx integration in patient care.

Areas Where PGx is Becoming Standard Care

There are many areas where PGx is becoming standard care today including:

  • Oncology: PGx testing has gained prominence in oncology to guide personalized cancer treatments. Identifying genetic mutations in tumors helps oncologists select targeted therapies, maximizing treatment efficacy while minimizing side effects.

  • Psychiatry: In the field of psychiatry, PGx testing aids in identifying the most suitable antidepressants, antipsychotics, and mood stabilizers based on a patient's genetic predisposition, leading to more effective mental health management.
  • Cardiology: PGx testing in cardiology assists in determining the optimal antiplatelet medications and dosages for patients undergoing stent placements or suffering from heart conditions, reducing the risk of cardiovascular events.

  • Infectious Diseases: PGx testing plays a role in infectious disease management, such as determining the right dosage of antiviral medications and antibiotics based on an individual's genetic response.

  • Pain Management: PGx testing helps in identifying patients who may be more sensitive to opioids, allowing for personalized pain management strategies and reducing the risk of opioid-related adverse effects.

  • Gastroenterology: In the treatment of gastrointestinal disorders, PGx testing helps tailor drug choices and dosages for better patient response and reduced gastrointestinal side effects.

  • Rheumatology: PGx testing is increasingly used in rheumatology to optimize treatment outcomes for patients with autoimmune conditions like rheumatoid arthritis, selecting medications that align with their genetic profile.

Limitations and Challenges to PGx Adoption

PGx is an evolving field so there are limitations and challenges to PGx adoption.

“Although it is clear that PGx testing is valuable, it presents a number of challenges to physicians, clinical diagnostic laboratories, and healthcare institutions,” said an industry white paper.

  • Limited Clinical Evidence: While PGx holds great promise, some medications lack robust clinical evidence supporting their correlation with specific genetic variants, leading to uncertainty in certain drug-gene associations.

  • Ethical Considerations: PGx testing involves handling sensitive genetic information, raising concerns about patient privacy, data security, and the potential misuse of genetic data.

  • Diversity and Representation: Genetic variations may differ among different ethnic and racial groups, and ensuring diverse representation in PGx research and testing is essential to avoid disparities in healthcare outcomes.

  • Regulation and Standardization: The regulatory framework surrounding PGx testing needs to be more standardized to ensure uniformity in test accuracy and interpretation across different laboratories.

  • Physician Education: Many healthcare professionals may lack familiarity with PGx testing, necessitating comprehensive educational efforts to increase awareness and promote its widespread adoption.

Barriers to entry from the laboratory or hospital perspective, according to the white paper, include:

  • Capital equipment costs are high, with specialized instrumentation only available from a handful of vendors.

  • Tests and reagents need to be validated as well, which requires that laboratory technologists and laboratory directors have a good understanding of the science involved.

  • There are also regulatory hurdles with CLIA inspections and CAP accreditation.

“It’s fairly clear that payers will not pay for a pharmacogenomic test that does not have analytic and clinical validity and clinical utility,” concluded the white paper.

The Role of Clinical Laboratories in Educating Clinicians on PGx Results

Clinical laboratories have a pivotal role in educating clinicians about interpreting PGx test results.

They must provide comprehensive and easily understandable reports, detailing the significance of specific genetic variations and their impact on drug response.

Regular communication and collaboration between clinical laboratories and physicians help ensure that PGx information is effectively integrated into treatment decisions.

By providing valuable insights and guidance, clinical laboratories empower physicians to make informed choices for personalized patient care, unlocking the full potential of pharmacogenomics testing.

PGx Promises a Brighter Future for Personalized Medicine

PGx has rapidly evolved as a powerful tool in personalized medicine, guided by advancements in technology and the urgent need for molecular testing infrastructure in the face of the COVID-19 pandemic.

Its cost-effectiveness, coupled with collaborative efforts between pharmacists and physicians, has paved the way for its incorporation into various medical specialties, including oncology, psychiatry, cardiology, and more.

Despite some limitations and challenges, PGx holds immense promise in transforming the way we approach patient care, leading to safer and more effective treatments tailored to everyone’s unique genetic makeup.

As clinical laboratories continue to educate and support clinicians in interpreting PGx results, the future of personalized medicine shines bright, offering a new era of healthcare where genomic insights drive better health outcomes for all.