UK experts offer guidance on use of liver blood tests

Last Updated: 2017-11-21

By Anne Harding

NEW YORK (Reuters Health) - New UK guidelines are intended to help improve the use of liver blood tests, results of which the authors say has led to unnecessary repeat testing in people without liver disease, while often missing those with liver disease and severe fibrosis.

The Clinical Services and Standards Committee of the British Society of Gastroenterology commissioned the guidelines, which supersede a 2000 document. The new recommendations were published online November 9 in Gut.

The UK faces an increasing burden of alcohol-related liver disease, non-alcoholic fatty liver disease (NAFLD) and viral hepatitis, according to the report by Professor Philip N. Newsome of the University of Birmingham and colleagues. Mortality from liver disease has risen sharply, especially among younger people, they note.

Developed in the 1950s, liver blood tests - of bilirubin, albumin, international normalized ratio (INR) and platelet count - are the main tests for monitoring liver function, Newsome and his team point out. They are being used increasingly in both primary and secondary care to rule out liver disease and monitor for adverse drug effects - and in the workup of "the generally unwell patient." When these tests come back abnormal, they add, asymptomatic patients may be referred for another round of testing without considering the cause or severity of any potential liver disease.

"The problem with the use of these tests is they're often requested without perhaps sufficient consideration as to the question being asked," Dr. Newsome told Reuters Health in a telephone interview. "Absolute elevations of liver blood tests in isolation do not necessarily tell you a great deal about the severity of liver injury."

He said that he and his colleagues prefer the term "liver blood tests" to the commonly used "liver function tests" because "the vast majority of abnormal tests relate to abnormalities in liver enzymes rather than change in liver function."

The ratio of aspartate aminotransferase (AST) to alanine aminotransferase (ALT) can be "a useful predictor of whether or not a patient has liver fibrosis," he added.

The new guidelines, which cover adults and children, recommend that initial investigation in patients with potential liver disease should include bilirubin, albumin, ALT, alkaline phosphatase (ALP) and gamma-glutamyltransferase (GGT) plus a complete blood count. They also state that research is needed to determine whether case finding for NAFLD in high-risk groups is cost-effective before it can be recommended.

The new document establishes definitions for abnormal blood tests and a standard liver blood test panel, makes recommendations for when patients should have these tests, and offers advice on pathways and tools for managing patients with abnormal test results.

"The pathways will be freely disseminated and should be incorporated into primary care IT systems to allow automatic calculation of risk scores when appropriate, to ensure recommendations can be put into practice," the authors state.

The published guideline article includes a flowchart to aid clinicians in responding to abnormal liver blood test results, as well as decision algorithms for NAFLD and alcohol-related liver disease.

SOURCE: http://bit.ly/2zKf5j8

Gut 2017.