Highly Reliable Cell-Based Assay Enables Accurate Diagnosis of Endocrine Diseases

The conventional methods for measuring free cortisol, the body's stress hormone, from blood or saliva are quite demanding and require sample processing. The most common method, therefore, involves collecting urine over several days. However, this method requires great perseverance from patients, as collecting every drop of urine over several days can be nearly impossible, even if the patients are hospitalized. This often leads to up to 60% variation in urine-free cortisol measurements in individual patients. Now, researchers have developed a new method for measuring cortisol levels directly from a blood sample, marking a significant advancement in the diagnosis and treatment of various diseases.

Researchers from Aarhus University (Aarhus, Denmark) have discovered a groundbreaking method for measuring levels of free cortisol directly from a blood sample. This new method is simple and quick, requiring only a few drops of blood. This contrasts sharply with current practices, which are both cumbersome and inaccurate. Traditional tests, for instance, cannot differentiate between synthetic and natural cortisol. This limitation is problematic in patients who have been treated with synthetic cortisol, as it can lead to misdiagnoses or incorrect medication dosages. The new method addresses these issues by employing a cell-based assay, which not only improves the accuracy and reliability of cortisol measurements but also reduces the high variation commonly seen in patient samples

Image: The new versatile assay has the ability to measure both total and bioavailable cortisol from serum (Photo courtesy of Aarhus University)

An assay is an analytical procedure used to measure a substance's level, in this case, cortisol. The most common method currently is immunoassays using antibodies. However, the new method uses the cell-based assay HEK293F-GRE, which allows for the measurement of the total level of cortisol, including both natural free cortisol and synthetic cortisol from medicinal products. This new test has the potential to be a game-changer for diagnosing and treating patients who require cortisol regulation. This includes individuals with stress-related illnesses like anxiety and depression, chronic diseases such as diabetes and cancer, and inflammatory diseases like allergies and asthma. While there is still a need to explore how to best integrate this method into clinical practice, the goal is to make the test available using a standard blood sample for doctors, thereby improving patient care.

"Being able to measure the total cortisol level accurately means we can potentially adapt treatment more precisely and reduce the risk of side effects," said Andreas Lodberg, MD and postdoc at the Department of Biomedicine, Aarhus University. "Our validation shows that this method meets the stringent criteria set by the U.S. Food and Drug Administration, making it a promising candidate for future use in clinical laboratories."

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