Wednesday, February 02, 2005

Blood tests aren’t just for proving paternity

I have always been fascinated by how our DNA make-up interacts with our brain chemistry so this story in the Jerusalem Post has wide ranging repercussions and is certainly worthy of further follow-up:
Israeli researchers are the first to discover unique biomarkers in blood taken from patients treated in a hospital emergency room just hours after being exposed to a traumatic event, The Jerusalem Post has learned.

This physiological "signature" has been found to accurately identify the 12 percent or so of people who, about four months after the event, will develop post-traumatic stress disorder (PTSD), a serious mental condition whose symptoms can persist for years.

The discovery, to be published Wednesday morning in the on-line edition of Molecular Psychiatry, one of the world's leading psychiatric journals, offers the hope that eventually, a simple blood test can be used to screen trauma victims at high risk for PTSD and give them urgent therapy and/or medication.

PTSD is most successfully treated up to six months after the trauma. A highly reliable blood test would free professionals to focus immediately on those at high risk, treat them and follow them up rather than waiting until they complain of symptoms when it may be too late. Such focused screening would also save vital resources that would otherwise be spent on all trauma victims.

Among the symptoms of PTSD are sleep disorders, difficulty in concentrating, irritability, nightmares and flashbacks to the traumatic event. These can occur not only among those who were physically injured in traumatic events, but also among those who survived without a scratch.

The results describe how the researchers, headed by Hadassah University Medical Center psychiatry department director Prof. Arieh Shalev and colleague Dr. Ronen Segman, spent two years searching for and finding a physiological signature in peripheral blood cells, even though the changes that can be caused by a traumatic event occur mainly in the brain.

They took blood samples from 24 "shock casualties" who witnessed traumatic events and were brought to Hadassah's emergency department in 2003. Using a highly innovative methodology, they simultaneously examined thousands of possible biomarkers using microarrays (gene chips). Microarrays, which have been used to measure the activity of thousands of genes at one time in cancer or immune cells, have given scientists "snapshots" of gene activity that lead to better understanding of the cells and genetic machinery.

Of the 24 blood samples, certain biomarkers were found in 12 of the patients both in the emergency room and four months later. When all two-dozen patients were followed up four months later – generally considered the period after a traumatic event when PTSD sets in – the same 12 patients were diagnosed clinically with PTSD; the other 12 had none of these biomarkers, Shalev told the Post.

The researchers believe that after some improvement in the testing process, it will be possible to predict who will develop PTSD symptoms. Hadasit, the Hadassah subsidiary in charge of promoting and commercializing its researchers and intellectual properties, has already patented the findings and is in advanced stages of developing a commercial diagnostic kit for PTSD. Investors are being sought.

Shalev and Segman said that after discovering the signals, they were now concentrating on detecting the actual genes involved in PTSD. Their discovery is likely to lead to a blood test for PTSD in a few years, but it is also expected to shed more light on the biological processes that cause mental diseases and – it is hoped – to develop ways in four or five years to prevent them.

Shalev said that they did not take blood from trauma victims who suffered physical harm because "then we could not prove that the biomarkers were not affected by medications and treatments that they underwent in the emergency room. Those we tested did not undergo any physical medical procedure." Susceptibility to PTSD is apparently not a hereditary trait caused by a defective gene, Shalev said.
"We all have these genes. The question is which of them are expressed in the cells, meaning that they produce proteins that cause the brain to react differently and PTSD to appear."

Shalev and Segman hope the discovery will induce other researchers to investigate the connection between peripheral expression and central nervous system expression of disease that affects the brain. "If there is a peripheral signature in one psychiatric disease, there can be in others," Shalev said.

If you really must spend the public's purse, this seems like such a much more productive/beneficial medical research project on which to settle Cdn $8.1 million of the public’s largess on when compared to funding a study to learn how productive junkies are when the state becomes the supplier.

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