Biomarker (medicine)
It is also widely known that cholesterol values are a biomarker and risk indicator for coronary and vascular disease, and that C-reactive protein (CRP) is a marker for inflammation.
Biomarkers assess disease susceptibility and severity, which allows one to predict outcomes, determine interventions and evaluate therapeutic responses.
Several biomarkers have been identified for many diseases such as serum LDL for cholesterol, blood pressure, and P53 gene[6] and MMPs [7] as tumor markers for cancer.
In addition to long-known parameters, such as those included and objectively measured in a blood count, there are numerous novel biomarkers used in the various medical specialties.
Biomarkers are also seen as the key to personalised medicine, treatments individually tailored to specific patients for highly efficient intervention in disease processes.
[11] In addition, they indicate if the disease threatens to be severe with serious damage to the bones and joints,[12][13] which is an important tool for the doctor when providing a diagnosis and developing a treatment plan.
Testing a tumor for its KRAS status (wild-type vs. mutant) helps to identify those patients who will benefit most from treatment with cetuximab.
In these cases, biomarkers help to identify high-risk individuals reliably and in a timely manner so that they can either be treated before onset of the disease or as soon as possible thereafter.
For instance, pharmacodynamic (PD) biomarkers are markers of a certain pharmacological response, which are of special interest in dose optimization studies.
[22] An example is the traumatic brain injury (TBI) blood-based biomarker test consisted of measuring the levels of neuronal Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and Glial fibrillary acidic protein (GFAP) to aid in the diagnosis of the presence of cranial lesion(s) among moderate to mild TBI patients that is(are) otherwise only diagnosable with the use of a CT scan of the head.
[24] Predictive biomarkers are highly sensitive and specific; therefore they increase diagnostic validity of a drug or toxin's site-specific effect by eliminating recall bias and subjectivity from those exposed.
DNA biomarkers are essential in medical diagnostics and personalized medicine, primarily due to their stable and easily detectable nature.
[27] A well-known use case of DNA biomarkers is the detection of BRCA1 and BRCA2 mutations in breast cancer patients, which guides the use of preventive measures and targeted therapies.
[28] The advantage of DNA biomarkers lies in their ability to provide a permanent record of genetic alterations, which can be crucial for long-term disease monitoring.
Their static nature means they generally do not capture dynamic changes in gene expression or cellular states, which are crucial for understanding disease progression and treatment response.
Even in cases where disease-specific variations occur, such as tumor-associated mutations, DNA biomarkers provide limited insight into the real-time physiological condition of a disease.
Pattern-based RNA expression analysis provides increased diagnostic and prognostic capability in predicting therapeutic responses for individuals.
[29] RNA biomarkers offer a dynamic perspective on cellular activity, capturing gene expression patterns and regulatory processes.
Despite these trade-offs, RNA biomarkers remain highly valuable for studying dynamic cellular changes and regulatory processes, making them essential tools in precision medicine.
Protein biomarkers detect a variety of biological changes, such as protein-protein interactions, post-translational modifications and immunological responses.
Protein biomarkers can provide direct information about the functional state of cells and tissues, offering insights into disease mechanisms.
Proteins are generally stable in various conditions, such as temperature fluctuations and varying pH levels, which can make them easier to store and transport.
Protein biomarker detection methods, while effective, are not as high-throughput as sequencing-based approaches, limiting their scalability for large studies.
An example is neuronal Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and Glial fibrillary acidic protein (GFAP) can aid in the diagnosis of the presence a cranial lesion among moderate to mild TBI patients that is otherwise only diagnosable with the use of a CT scan of the head.
Coronary angiography, an invasive procedure requiring catheterization, has long been the gold standard for diagnosing arterial stenosis, but scientists and doctors hope to develop noninvasive techniques.
Tracking radiolabeled glucose is a promising technique because it directly measures a step known to be crucial to inflammation and tumor growth.
For example, at 1.5 tesla, a typical field strength for clinical MRI, the difference between high and low energy states is approximately 9 molecules per 2 million.
Innovative technology needs to be harnessed to determine the full capabilities of CTCs and ctDNA, but insight into their roles has potential for new understanding of cancer evolution, invasion and metastasis.
[43] Type 1 narcolepsy is caused by the loss of approximately 70,000 orexin-releasing neurons in the lateral hypothalamus, resulting in significantly reduced orexin levels in the cerebrospinal fluid (CSF) relative to healthy people.
For the disorders of central nervous system, the neuronal cell body-located Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and Glial fibrillary acidic protein (GFAP) are the first-in-class FDA cleared blood-based biomarker test for mild traumatic brain injury (TBI) with potential brain lesions.
