What are Biomarkers?

April 23, 2024

Screening for blood biomarkers has been proposed as a potential way to diagnose cancer at earlier stages of the disease.

About Biomarkers:

Biomarkers, short for ‘Biological Markers’ are a physical, chemical or biological characteristic that is present in the human body and measurable too.
The WHO defines a biomarker as “any measurement reflecting an interaction between a biological system and a potential hazard, which may be chemical, physical or biological. The measured response may be functional and physiological, biochemical at the cellular level or a molecular interaction”.
Experts also call them molecular markers and signature molecules. They are indispensable in diagnosing disease, prescribing the right medication, right dosage, and even while designing new drugs.
- Biomarkers include biomolecules like carbohydrates, proteins, lipids, genes, DNA, RNA, platelets, enzymes, hormones, etc.
Classification of Biomarkers:
- Based on their source or location:
  - Molecular– have biophysical properties, which allow their measurements in biological samples such as blood plasma, serum, cerebrospinal fluid, bronchoalveolar lavage, biopsy, urinalysis, and faecal analysis
  - Radiographic– obtained from imaging studies, for example, bone mineral density
  - Histologic– reflect biochemical or molecular alteration in cells, tissues, or fluids; for example, the staging and grading of cancers
  - Physiologic– measures of body processes, for example, blood pressure, pulse rate, and heart rate
- Based on roles/functions:
  - Susceptibility/Risk Biomarkers: Indicate the person’s likelihood of developing a particular disease or condition in the near or distant future.
  - Diagnostic Biomarkers: These are used to detect or confirm a particular disease or condition.
  - Prognostic Biomarkers: In people who already are confirmed to have a disease, prognostic biomarkers can predict the likelihood of disease progression or relapse.
  - Monitoring Biomarkers: These biomarkers are used for one or all of these reasons: to assess the stage or condition of the disease, to measure the exposure to a particular drug and to measure exposure to an environmental agent.
  - Predictive Biomarkers: These are used to identify individuals who have a higher likelihood of experiencing a strong outcome when exposed to a particular drug. This will help decide the treatment options.
  - Pharmacodynamic/Response Biomarkers: These reveal that a biological response has happened in patients exposed to a particular drug or environmental agent.