Scientists at the universities in Tübingen and Mainz say they have developed a blood test that can provide conclusive proof of gene doping - even after 56 days.

To date, it has been impossible to prove that an athlete had undergone gene doping but they say the new test provides a clear answer based on whether or not transgenic DNA is present in blood samples. Transgenic DNA (tDNA) does not stem from the person being tested but has been transferred into their body, often via viruses, in order to create performance-enhancing substances such as erythropoetin (EPO) for forming red blood cells. 

In 2006, as a member of the University Hospital in Tübingen, professor Perikles Simon, MD, PhD from Johannes Gutenberg University Mainz, developed a procedure that enabled traces of transgenic DNA to be detected in the blood. The efficiency of this procedure has now been proven for the first time in laboratory mice. A key component of the animal procedure was a process that was able to insert the foreign genetic material extremely specifically to the muscles around a small puncture area.

This triggers excess production of a hormone, which prompts the generation of new blood vessels. Even two months after the genes were injected into the muscles, researchers were able to differentiate clearly between the mice subjected to gene doping and those that were not.

"For the first time, a direct method is now available that uses conventional blood samples to detect doping via gene transfer and is still effective if the actual doping took place up to 56 days before," said Simon. "The body of a gene-doped athlete produces the performance-enhancing hormones itself without having to introduce any foreign substances to the body. Over time, the body becomes its own doping supplier.   The development of a reliable method for detecting misuse of gene transfer will be used to ensure that this new technology, for which the side effects are only partially known, is used exclusively in the treatment of severe diseases." 
"The process of inserting individual genes in specific body cells stems from the idea of curing severe illnesses with this new technology. It was previously thought that it would only be possible to detect gene doping via gene transfer using an extremely costly indirect test procedure from the field of molecular medicine," explained gene therapist Professor Michael Bitzer, MD from the University Hospital of the Eberhard Karls University of Tübingen.

The detection procedure developed by the scientists in Mainz and Tübingen was proven in a so-called specificity test on 327 blood samples taken from professional and recreational athletes. Researchers now believe that athletes will no longer profit from the misuse of gene therapy for doping purposes. "At the very least, the risk of being discovered months after the gene transfer has taken place should deter even the most daring dopers," Simon believes. The World Anti Doping Agency (WADA) has financed this research over the past four years with a total of $980,000.

Citation: T. Beiter, M. Zimmermann, A. Fragasso, J. Hudemann, A.M. Niess, M. Bitzer, U.M. Lauer , P. Simon, 'Direct and long-term detection of gene doping in conventional blood samples',  
Gene Therapy, 2010; doi: 10.1038/gt.2010.122