Biomarkers: Promising and valuable tools towards diagnosis, prognosis and treatment of Covid-19 and other diseases

Abstract

The use of biomarkers as early warning systems in the evaluation of disease risk has increased markedly in the last decade. Biomarkers are indicators of typical biological processes, pathogenic processes, or pharmacological reactions to therapy. The application and identification of biomarkers in the medical and clinical fields have an enormous impact on society. In this review, we discuss the history, various definitions, classifications, characteristics, and discovery of biomarkers. Furthermore, the potential application of biomarkers in the diagnosis, prognosis, and treatment of various diseases over the last decade are reviewed. The present review aims to inspire readers to explore new avenues in biomarker research and development.

Keywords: Biomarker; Cancer; Covid-19; Diagnosis; Diseases; Imaging; Treatment.

Fig. 1

The principal features of an ideal biomarker.

Fig. 2

Schematic presentation of classification of biomarkers.

Fig. 3

Some examples of chemical biomarkers.

Fig. 4

Two types of protein biomarkers. (a) Glycosylated or glycated hemoglobin (HbA1c) is a form of hemoglobin (type A) that is known as a protein biomarker, and is a common blood test that can be used for type 1 and 2 diabetes mellitus monitoring. (b) Angiotensin-converting enzyme is a dipeptidyl carboxypeptidase and a central component of the renin-angiotensin system which as a favorable biomarker plays a vital role in the diagnosis and prognosis of various diseases.

Fig. 5

Examples of imaging biomarkers. (a) Computed tomography (CT): A useful screening tool for obtaining detailed images of various internal regions of the body using a series of X-rays and computer technology. (b) Positron emission tomography (PET): A nuclear imaging procedure that uses small amounts of radioactive drugs to reveal the metabolic activity of tissues and organs of the body. Some examples of imaging biomarkers. (c) Endoscopy: A procedure to observe and examine the inside of the body without performing major surgery using a flexible tube equipped with a lens and a video camera at two tube heads. (d) Magnetic resonance imaging (MRI): A technique to obtain clear images of different organs and structures inside the human body using magnets, radio waves, and a computer. (e) Mammography: A medical imaging process using an X-ray source with low energy to examine breast tissue for early detection of cancer. (f) Optical coherence tomography: A high-resolution and noninvasive imaging method to obtain 2D and 3D images from within biological media based on the interference signal between the sample and a local reference.

Fig. 6

The taxonomy of “omics” technologies.

Fig. 7

Framework for the development of biomarkers. To find potential biomarkers, tissue extracts or biological fluids can be used in the discovery process. Urine, synovial fluid, cerebral fluid, blood, saliva, and tissue extracts are a few examples of the numerous biofluids that might act as the discovery matrix for biomarkers. During the discovery process, biomarker qualifying in samples (either in vitro or in vivo from animals or humans) gives confidence that the biomarkers may have clinical utility. For qualifying companion diagnostics or techniques associated with the development and regulatory approval of a therapeutic or drug, both the European Medicines Agency and the FDA have formal approval procedures.