Noninvasive combo tests for liver damage could replace biopsies in PBC
Study: Simple scan plus blood test may accurately predict liver scarring
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A noninvasive liver scan used alongside a standard blood test may accurately predict the severity of liver scarring, or fibrosis, in people with primary biliary cholangitis (PBC) — potentially reducing the need for invasive liver biopsies, a new study reports.
This novel combo testing strategy employs a type of ultrasound scan and data from a routine blood draw. The approach uses the scan’s liver stiffness measurement (LSM) together with blood levels of alkaline phosphatase (ALP), a marker of reduced bile flow — a condition known as cholestasis and a key feature of PBC — to assess fibrosis levels.
Researchers found that two models combining these measures could accurately identify PBC patients with moderate and advanced liver fibrosis. Further, they even outperformed several standard blood-based markers used to estimate fibrosis stage.
These models “were the efficient noninvasive” tools “with high accuracy in predicting” the stage of liver fibrosis in PBC, the researchers wrote, adding that such noninvasive measures are “extremely necessary” in PBC to help doctors evaluate a patient’s prognosis and adjust treatment plans in a timely way.
The study, “Noninvasive elastography-based assessment of liver fibrosis in primary biliary cholangitis,” was published in Annals of Hepatology.
A chronic form of cholangitis, PBC is marked by inflammation of the bile ducts, the channels that carry the digestive fluid bile from the liver to the intestines. This causes bile to accumulate to toxic levels in the liver, which, over time, can lead to fibrosis. As the scarring worsens, it may eventually progress to cirrhosis, where liver damage becomes irreversible, and liver function declines.
‘No reliable alternative’ to liver biopsies in PBC
The severity, or stage, of liver fibrosis is known to be one of the strongest predictors of long-term outcomes in PBC, even in patients whose blood tests suggest they are responding to standard treatment. However, measuring fibrosis usually requires a liver biopsy, which is an invasive procedure that carries risks and, as such, isn’t routinely used to monitor disease over time.
Given that “there are still no reliable alternative markers for staging liver fibrosis in PBC,” the researchers noted that “there is still a need to develop non-invasive methods for liver fibrosis assessment and monitoring.”
One promising noninvasive measure of liver fibrosis is LSM using transient elastography, a type of ultrasound that measures how stiff the liver is. It’s already proven useful in assessing liver fibrosis in other chronic liver diseases.
“However, there is limited evidence on its accuracy at the assessment of liver fibrosis in PBC,” the researchers wrote.
To address this gap, a team of researchers in China set out to develop a noninvasive model to predict fibrosis stage in people with PBC using transient elastography, and to compare its performance with established blood-based markers of fibrosis, using liver biopsy results as the reference standard.
The team retrospectively analyzed data from 144 people with PBC who underwent liver biopsy at a single Chinese hospital between January 2012 and May 2024. Blood tests and transient elastography measurements were performed within a week prior to biopsy.
The patients’ median age was 50.5 years and most (88%) were women. In terms of disease stage, 38.2% had minimal liver fibrosis, 30.6% had significant fibrosis, 25.7% had advanced fibrosis, and 5.6% had cirrhosis, the data showed.
New model outperformed commonly used tests for liver damage
To develop and test the tool, the researchers divided patients into two groups: Information from 96 individuals was used to build the prediction models, while data from 48 were used to validate them. The two groups did not differ significantly in their demographic and clinical characteristics.
In the model-building group, statistical analyses that accounted for multiple factors showed that LSM and blood ALP levels were each strong predictors of significant liver fibrosis.
The scientists combined these two measures into mathematical formulas: one, designed to predict significant fibrosis, was referred to as Model A, and another aimed at predicting advanced fibrosis was known as Model B.
Both models were evaluated to determine their accuracy using a standard measure called the area under the receiver operating characteristic curve, or AUROC. Scores range from 0.5 to 1, with higher scores indicating better predictive potential.
In the model-building group, Model A achieved an AUROC of 0.87, while Model B reached 0.95, indicating the tools were very good at correctly discriminating patients with moderate and severe liver scarring from those without, according to the researchers. The team noted that both models outperformed several commonly used blood-based markers for estimating liver fibrosis.
[The data show that this testing] combination … can improve diagnostic accuracy for assessing fibrotic stage.
When tested in the separate validation group, the models’ performance remained strong, the data showed. Model A had an AUROC of 0.91, and Model B reached 0.91, suggesting the approach remained reliable in a different set of patients. Both models continued to outperform standard blood-based fibrosis markers.
The researchers concluded that “a combination of LSM plus ALP can improve diagnostic accuracy for assessing fibrotic stage.” They added, however, that larger studies involving more patients at multiple centers are needed to further validate the models’ performance.
