Blood doping

Having already posted about doping a week or two ago following the olympics I thought I would research blood doping following the accusations against Lance Armstrong and this is what I learnt...

Blood doping is the act of increasing the number of red blood cells (rbc) in the bloodstream in order to enhance athletic performance. Consequently haemoglobin (hb) the oxygen transporting molecule is also increased improving an athletes capacity (VO2 Max) and endurance. There are two types of blood doping, Homologous and Autologous doping.

A measure of rbc count is hematocrit, which is the volume percentage of rbc within the blood. This is normally around 45% for men and 40% for women as an average.

Homologous doping involves extracting someones compatible blood, concentrating the rbc, storing them and later transfusing them by injection before exercise. However a chemical test was developed in 2004 to identify anyone guilty of homologous doping, in very simple terms the test examines markers on the surface of blood cells with the ability to determine whether blood from more than one person is present in the athletes circulation.

Hence Autologous doping became more popular, the extraction of ones own blood, concentrating the rbc, storing them and later transfusing them by injection before exercise. The World Anti-Doping Association (WADA) are developing a test to compare the age of blood cells which has not yet reached official testing standard. The test compares the number of 'mature' (erythrocytes) and 'immature' (reticulocytes) rbc. Cells are marked using a fluorescent dye which marks RNA and DNA and automatically counted using laser technology. Erythrocytes have neither RNA or DNA, reticulocytes have a small amount of RNA and lymphocytes (white blood cells which are also present) have a large amount of DNA. The differences in dye concentration can easily be used to distinguish between the cells and there should be standard proportion of 'mature' to 'immature' rbc.

Hormones can also be used to increase rbc count and are often harder to detect. For example erythropoietin (EPO) stimulates the formation of rbc and is used medically as a treatment for anemia (deficiency of rbc). Athletes sometimes abuse this medical drug and use its properties to enhance performance.