A color-coded “traffic light” blood test can diagnose liver cirrhosis and fibrosis in heavy alcohol drinkers much more easily and accurately than present diagnostic approaches, researchers from the University of Southampton and Southampton General Hospital, England, reported in the British Journal of General Practice. The authors added that the test could be used by GPs (general practitioners, primary care physician) to determine rapidly whether high risk patients have liver damage.

The problem with liver disease is that symptoms are not usually noticeable until there is liver failure, by which time it is too late to do anything about it. Approximately one third of patients who are hospitalized with end-stage liver disease do not survive for more than a few months.

A simple test performed by general practitioners could detect liver damage early on, which would allow doctors to be able to encourage their patients to alter their lifestyles in time.

Called the Southampton Traffic Light Test, or STL, it is a combination of various tests and clinical markers which provide a score that indicates how likely it is for a patient to develop fibrosis or cirrhosis of the liver.

The results are color coded:

  • Red – the patient has fibrosis (liver scarring); there is a chance of cirrhosis

  • Green – no cirrhosis detected. The likelihood of dying form liver disease during the next five years is negligible

  • Amber – there is a 50+% risk of scarring. The chances of dying during the next five years are high. The patient is encouraged to stop drinking alcohol to stop the liver damage from getting worse, and to prevent premature death.

The team tried out the test on over 1,000 participants. They monitored them all afterwards; some of them for several years. The aim was to determine how accurate the test is in predicting liver fibrosis or cirrhosis.

The test was accurate in cases of severe liver disease. The authors stressed that the test is not a substitute for liver function tests or clinical judgment. However, it can provide primary care doctors with a rapid and accurate way to assess whether patients have liver damage and to what extent. This would be especially useful for usage with high-risk patients, such as obese individuals, people with type 2 diabetes, and heavy drinkers.

Lead author, Dr Nick Sheron, said:

“We are reliant on general practitioners detecting liver disease in the community so they can intervene to prevent serious liver problems developing, but so far we haven’t been able to give them the tools they need to do this. We hope that this type of test for liver scarring may start to change this because the earlier we can detect liver disease, the more liver deaths we should be able to prevent.”

Dr Michael Moore, a primary care physician and co-author of the report, said:

“In primary care, minor abnormalities of existing liver tests are quite common but we struggle to know how best to investigate these further and who warrants specialist intervention. The traffic light test has the advantage of highlighting those at highest risk who should be investigated further and those in whom the risk is much lower where a watchful approach is more appropriate. This is not a universal screening test but if targeted at those in whom there is a suspicion of liver disease should result in a more rational approach to further investigation.”

Professor Sir Ian Gilmore, chair of the Alcohol Health Alliance added: “One of the challenges of liver disease, which is rising dramatically in this country, is the silent nature of the condition until it is often too late to reverse the damage. However, minor changes in standard liver blood tests are so common that it is difficult for GPs to know when to refer for specialist advice. This large study from Dr Sheron and colleagues in Southampton may prove really useful for guiding the right patients towards specialist care in a timely way.”

Cirrhosis is a type of abnormal liver condition with irreversible scarring of the liver. It usually develops over a period of many years.

When healthy liver tissue is destroyed, scar tissue replaces it. As this process progresses, it can start blocking the flow of blood through the liver, leading to liver failure (the liver stops functioning). The main causes of cirrhosis are long-term heavy drinking, viral hepatitis B and C, and fatty liver disease.

Written by Christian Nordqvist