A new ‘traffic light’ test devised by Dr Nick Sheron and colleagues at University of Southampton and Southampton General Hospital could be used in primary care to diagnose liver fibrosis and cirrhosis in high risk populations more easily than at present.
Liver disease develops silently without symptoms, and many people have no idea they have liver failure until it is too late – one-third of people admitted to hospital with end-stage liver disease die within the first few months. A simple test available in primary care could diagnose disease much earlier, enabling those at risk to change their behaviour and save lives.
The Southampton Traffic Light (STL) test, details of which are published in the September 2012 issue of the British Journal of General Practice (BJGP), combines several different tests and clinical markers which are given a score that indicates the patient’s likelihood of developing liver fibrosis and liver cirrhosis.*
The result comes in three colours: red means that the patient has liver scarring (fibrosis) and may even have cirrhosis, green means that there is no cirrhosis and the patient is highly unlikely to die from liver disease over the next five years. Amber means there is at least a 50:50 chance of scarring with a significant possibility of death within five years, and patients are advised to stop drinking to avoid further disease and death.
The test was given to over 1,000 patients, and their progress was carefully followed and monitored afterwards, in some cases over several years, to assess the accuracy of the test in predicting whether they developed liver fibrosis or cirrhosis.
The test proved to be accurate in severe liver disease, and while not a substitute for clinical judgement or other liver function tests, can provide GPs with an objective means to accurately assess the potential severity of liver fibrosis in high-risk patients – for example, heavy drinkers, those with type II diabetes, or obese people.
Dr Nick Sheron, lead author and Head of Clinical Hepatology at the University of Southampton, and consultant hepatologist at Southampton General Hospital, 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.”
Study co-author and GP Dr Michael Moore 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.”
*The Southampton Traffic Light (STL) algorithm combines two serum markers of fibrosis, collagen p3 n peptide (P3NP) and hyaluronic acid (HA), together with platelet count, and can be calculated in two ways: either with a complex exponential function derived from logistic regression analysis, or, alternatively, with a simple clinical rule for the individual test results:
- HA >30 μg/l or P3NP >5.5 μg/l – score +1
- HA >75 μg/l – score +2
- platelet count <150 x 109/l – score +1
- total score: 0 = green, 1 = amber, 2 or more = red.
Source: University of Southampton