Biomedical Engineering Reference
In-Depth Information
1 Introduction
1.1 The Concept of Molecular Biomarkers
The last two decades have seen extensive effort put into genome and proteome
research which has led to a deeper understanding of the molecular basis of diseases,
their occurrence, development, and cure. As a consequence of this knowledge,
more suitable therapies are on the horizon and are discussed widely as ''person-
alized medicine''. Molecular diagnostics will be an integrated part of this concept,
since medication, success of treatment but also early occurrence of specific
biomarkers for early detection of disease or even presymptomatic diagnosis will
become the focus of medical treatments. Also genetic markers for risk screening
and all aspects of companion diagnostics that define medication by the genetic
constitution of a patient will help provide improved therapy.
Therefore, the molecular in vitro diagnostics market has good forecasts and is
regarded to be a worldwide increasing market. Especially combined with point-of-
care testing (sometimes better described as point-of-need) in vitro diagnostics might
significantly improve the benefit obtained from molecular knowledge. Biochip- and
Lab-on-Chip technologies designed for routine application open up the opportunity of
performing complex analysis and multiparameter analysis on a small scale. Lab-on-
Chip systems have the potential to transfer molecular diagnostics to the point-of-need.
A key component of the future development of diagnostics is the concept of
biomarkers. In general biomarkers are all kinds of parameters that may be obtained
from a patient and that are quantitative and correlate to a particular disease. Usually
a biomarker qualifies to be called a surrogate marker when evidence has been
gained from clinical studies that the biomarker represents a certain disease, a dis-
ease stage, or the patient's reaction towards a particular treatment or medication.
While the general concept of a biomarker includes all kinds of physiological data
such as heart beat and lung volume, molecular biomarkers concentrate on bio-
chemical or genetic parameters and patterns thereof, sometimes named signatures.
In addition, diagnostics becomes more complex when a deeper look at these
various biomarkers is necessary (Fig.
1
). Within the Human Genome Project about
25,000 genes were identified. Considering the dogma of molecular biology these
genes are transcribed to various forms of RNA, then translated into proteins and
post-translationally modified. Going one step further, also variation in metabolism
may be linked to diseases as well. In this regard, genomic, proteomic, glycomic,
and metabolomic research has led to the need for detection and quantification of
completely different types of analytes ranging from genes and proteins to small
molecules and combinations thereof.
A multitude of detection methods are needed to match the requirements of each
analyte. However, in many cases these methods are too sophisticated for routine
diagnostics and in most cases too expensive as well. Hence, there is a need for
new, more user-friendly technologies. This will lead to benefits for many patients
and additionally may help to reduce costs caused by false and delayed treatments.
