Single Hair Analysis Monitoring Concept for P4 Implementation

P4 medicine is a holistic concept describing man as a complex biological system. With a viewpoint of general healthcare management this concept focuses mainly on prevention and not curative treatment. On the other hand, forensic toxicology investigates (adverse) effects caused by drugs and chemicals in cases with medicolegal consequences. Thus, on a first glance, these two concepts seem to have nothing in common. Hair testing is a young technique among all the analytical tools applied in forensic toxicology. The main advantage of this method is the prolonged time frame represented by a segment of the keratinized part of the hair. This allows long term monitoring of exposure, not only to drugs, but also to environmental influences or situations pertaining to health such as, for example, an on-going stressful situation. Hair metabolomics hast just started; however, the development of new markers will-together with standardized toxicological hair analysis-enable a predictive and preventive monitoring over a controlled time frame. The highly sophisticated techniques currently developed for single hair analysis allow an even deeper insight into hair, incorporation pathways, but also degradation mechanisms. Even today, first experiments have shown that metabolic ratios observed in the hair matrix might provide some evidence for the phenotype of the individual regarding metabolism. A single hair does not only consist of a dead, keratinized part containing mitochondrial DNA (mtDNA). The hair follicle at the bottom end of a plucked hair contains enough nuclear DNA (nuDNA) for complete sequencing. In addition, microscopic examination of the hair follicle is used to determine the state of the hair growth cycle the hair is in. In summary, single hair analysis allows individual characterization and therefore supports personalized assessment and facilitates participatory medicine