Protein May Lead to More Accurate Diagnostic Test for Alcohol Consumption
William M. Freeman, Ph.D, department of pharmacology and lead investigator, said that the challenge with alcohol abuse as opposed to illicit drug use is that alcohol is legal for those over 21. Working with Kathleen A. Grant, Ph.D., at the Oregon National Primate Research Center, Freeman and other Penn State Hershey researchers identified a set of 17 proteins in the blood that accurately predicted alcohol use 90 percent of the time in non-human primates. They were able to separate alcohol consumption into three categories: no drinking, drinking up to two drinks per day, and drinking at least six drinks per day.
Depending on alcohol consumption, protein levels increased or decreased with as little as one to two drinks per day, and the same changes occurred with heavier levels of drinking, according to Dr. Freeman. The researchers also found other proteins that would only respond to heavy drinking. Taken together, the proteins allowed the researchers to classify the participants into non-drinking, drinking, and alcohol abusing groups.
The researchers will now work on determining whether stopping drinking makes the protein levels return to normal. They’re also looking for additional proteins to help improve accuracy and provide alternates if some of the initial 17 proteins don’t work in humans. They plan to collect blood from people undergoing inpatient treatment for alcohol dependency.
The ultimate goal is to create a diagnostic test for alcohol consumption that can be used for public safety, such as with pilots or those who work for national security, for parole conditions, and for helping doctors screen for alcohol abuse in their patients. There are some tests that try to address the issue, but Dr. Freeman said they aren’t sensitive or specific enough, and many of them rely on just one protein.
Dr. Freeman explained that the current tests often look at proteins produced by the liver, noting that while the protein levels increase with heavy drinking, they also increase with any injury to the liver. The current tests alert clinicians that the liver is being stressed, but they can’t discriminate between heavy drinking and other conditions, like taking prescription medication that is hard on the liver.
By creating their new diagnostic tests, Dr. Freeman hopes to produce a “unique fingerprint” that is less likely to be affected by unrelated conditions. They would not be testing for alcohol dependence, but for alcohol intake.
Dr. Freeman explained that they can’t use a blood test to determine whether an individual’s drinking is problematic, but that their test can hopefully prompt a referral to a treatment center if the results indicate that an individual has been drinking a great deal.
Source: Science Daily, Proteins May Point to Alcohol Use Test, April 12, 2010.