Do you really need a needle biopsy to find out whether a fatty liver has started to scar? Less and less often. On 29 October 2026, two large international studies from the LITMUS programme, published in The Lancet and Nature Medicine, compared dozens of non-invasive liver fibrosis tests against liver biopsy. One finding stood out: GGT, a routine enzyme already printed on many liver function tests, worked better than the widely used FIB-4 score as the first step of screening. Here is what the research shows, what it changes for patients, and what it does not change yet.
What the LITMUS study in The Lancet found
LITMUS is a European research programme funded by the Innovative Medicines Initiative (IMI2), bringing together 53 academic and industry partners. Its main study enrolled 1,590 adults with metabolic dysfunction-associated steatotic liver disease (MASLD, formerly called NAFLD), recruited between 2018 and 2023 at centres in 13 countries across Europe and the United States. Every participant had a liver biopsy, read centrally by expert pathologists, so each test could be checked against the gold standard.
The researchers evaluated 12 single markers and 18 multi-marker panels, including blood tests, calculated scores and liver stiffness measurements. Before looking at the data, they set a minimum accuracy level that a test would need to reach to be considered a possible replacement for biopsy. The key results:
- Advanced fibrosis and cirrhosis: several tools reached that level, led by a blood protein panel (SomaSignal, based on SOMAscan technology) and by scores that combine blood tests with FibroScan elastography (FibroMeter-VCTE, Agile 3+). For cirrhosis, the ELF and ADAPT blood tests also passed the bar.
- "At-risk MASH" (active liver inflammation plus significant scarring, the group targeted by most drug trials): only the protein panel met the threshold. Detecting active inflammation remains the hardest problem.
- First-line triage: a two-step approach that starts with a simple GGT blood test, then adds a second test (ELF or FibroScan) for people flagged by GGT, met the accuracy target for both advanced fibrosis and at-risk MASH. According to Newcastle University, which co-led the work, GGT outperformed FIB-4 in this first-filter role.
The companion LITMUS Imaging Study in Nature Medicine, which included more than 350 patients, compared imaging tools and found that magnetic resonance elastography (MRE) was more accurate than FibroScan-based stiffness measurements, although MRE is mainly available in specialist centres. "For advanced liver scarring and cirrhosis, we now have tools good enough to use with real confidence," said Professor Quentin Anstee of Newcastle University, the programme's coordinator.
GGT, FIB-4, ELF, FibroScan: which liver fibrosis test does what?
The table below summarises the role of each test, based on the LITMUS results and current US and European guidance.
| Test | Type | Role today | What LITMUS adds |
|---|---|---|---|
| GGT | Routine blood test | Liver function test enzyme, not specific | Better first filter than FIB-4, still to be confirmed |
| FIB-4 | Score from age, AST, ALT and platelets | Recommended first test in the US and Europe | Outperformed by GGT in this cohort |
| ELF | Specialised blood test (3 fibrosis markers) | Second step when elastography is not available | Reliable for detecting cirrhosis |
| FibroScan and combined scores | Ultrasound-based liver stiffness | Standard second step | Among the most accurate for advanced fibrosis |
| MR elastography | MRI imaging | Specialist centres | More accurate than FibroScan |
| Liver biopsy | Needle sample | Reference, kept for unclear cases | Still needed for active inflammation and trials |
One important caveat: GGT is not a fibrosis-specific marker. It also rises with alcohol, some medicines and bile duct problems, as explained in our GGT test guide. That is why the researchers propose it only as a filter, always followed by a second test, never as a diagnosis on its own.
Recent advances: towards simpler liver screening pathways
LITMUS arrives as liver specialists try to organise fibrosis screening more efficiently. In 2023, international liver societies renamed the disease (MASLD instead of NAFLD) to highlight its links with excess weight, diabetes and high blood pressure. In 2024, the American Association for the Study of Liver Diseases (AASLD) and the European societies (EASL, EASD, EASO) both endorsed a two-step approach: start with a simple blood-based score, then move on to elastography or an ELF test if the result is not reassuring.
Other recent work points in the same direction as LITMUS. A 2026 modelling study in PLOS One, focused on people with type 2 diabetes in primary care, found that adding a GGT check when FIB-4 was inconclusive identified more cases of advanced fibrosis while avoiding unnecessary specialist referrals. A 2026 review in Liver International confirmed that step-by-step pathways improve how patients are sorted, but noted that some people drop out before completing all the recommended tests. For you, this means a value that may already appear on a routine blood test could, in the near future, play a bigger role in deciding who needs further liver testing.
The limits matter too. LITMUS participants were hospital patients who had undergone a biopsy, so advanced fibrosis was far more common among them than in the general population. The authors themselves call for further validation before their pathway is adopted, and FIB-4 remains the recommended first test for now.
Which tests can monitor or screen for liver fibrosis?
Doctors mainly look for liver fibrosis in people with type 2 diabetes, obesity with at least one other metabolic risk factor, fatty liver seen on an ultrasound scan, or abnormal liver enzymes. Useful tests include:
- liver function tests: AST, ALT, GGT, alkaline phosphatase and bilirubin;
- a platelet count, needed to calculate FIB-4 together with your age, AST and ALT;
- fasting glucose or HbA1c and a cholesterol (lipid) profile, to assess related risk factors (see our guide to diabetes blood tests);
- if the first step is not reassuring: elastography (FibroScan) or a specialised blood test such as ELF, requested by your GP or a liver specialist.
For background on how routine blood tests relate to fatty liver, read our earlier article on the fatty liver blood test.
When to see a doctor
Speak to your GP if your GGT or liver enzymes are high on more than one test, if an ultrasound scan showed a fatty liver, or if you have type 2 diabetes or significant excess weight and have never had your liver assessed. Persistent tiredness, a swollen tummy, leg swelling, yellowing of the skin or eyes, or unusual bleeding or bruising call for a prompt appointment. If you vomit blood or feel faint, call 999.
Glossary
- MASLD: metabolic dysfunction-associated steatotic liver disease, a build-up of fat in the liver linked to excess weight, diabetes or high blood pressure.
- MASH: the inflammatory form of MASLD, which can drive scarring.
- Fibrosis: scarring of the liver after repeated injury, graded from F0 (none) to F4 (cirrhosis).
- Cirrhosis: the most advanced stage of fibrosis, in which the liver's structure is deeply altered.
- GGT: gamma-glutamyl transferase, a liver and bile duct enzyme measured in a blood test.
- FIB-4: a score calculated from age, AST, ALT and platelet count that estimates the likelihood of advanced fibrosis.
- ELF: Enhanced Liver Fibrosis test, a blood test measuring three molecules involved in building and breaking down scar tissue.
- Elastography: a painless test that measures liver stiffness, by ultrasound (FibroScan) or MRI.
Frequently asked questions
Does a high GGT mean I have liver fibrosis?
No. GGT rises for many reasons, including alcohol, some medicines and bile duct conditions. LITMUS suggests using it only as a first filter, followed by another test for anyone it flags.
Is the FIB-4 score outdated?
Not yet. It is still the recommended first test in US and European guidance. LITMUS suggests a pathway starting with GGT could perform better, but that needs confirmation, especially in primary care.
Can I avoid a liver biopsy?
In most cases, yes: blood tests and elastography are often enough to detect advanced fibrosis or cirrhosis. A biopsy is still useful when results conflict, to assess active inflammation, or to enrol in a clinical trial.
Is the ELF test part of a routine blood test?
No. ELF is a specialised blood test, not part of standard liver function tests. Guidelines position it as a second step, usually when FIB-4 is not reassuring and elastography is not easy to access, so your doctor would request it specifically.
Can liver fibrosis be reversed?
In the earlier stages, weight loss, avoiding alcohol and better diabetes control can slow fibrosis and sometimes reverse it. That is why finding it early matters.
Sources
- Vali Y et al. Non-invasive tests in metabolic dysfunction-associated steatotic liver disease: the LITMUS prospective multicentre diagnostic accuracy study. The Lancet, 2026. DOI: 10.1016/S0140-6736(26)01145-1
- Pavlides M et al. Prospective validation of imaging and serum diagnostic biomarkers of steatohepatitis and fibrosis in MASLD: the LITMUS Imaging Study. Nature Medicine, 2026. DOI: 10.1038/s41591-026-04496-2
- Sterling RK et al. AASLD Practice Guideline on blood-based noninvasive liver disease assessment of hepatic fibrosis and steatosis. Hepatology, 2024. DOI: 10.1097/HEP.0000000000000845
- EASL, EASD, EASO. Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD). Journal of Hepatology, 2024. DOI: 10.1016/j.jhep.2024.04.031
- Rinella ME et al. A multisociety Delphi consensus statement on new fatty liver disease nomenclature. Journal of Hepatology, 2023. DOI: 10.1016/j.jhep.2023.06.003
- Poh W et al. Cost-effectiveness of various referral pathways to identify advanced fibrosis among type 2 diabetes mellitus patients with MASLD in primary care setting in Malaysia. PLOS One, 2026. DOI: 10.1371/journal.pone.0350263
- van Eekhout KMA et al. Care Pathways for Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): A State-of-The-Art Review. Liver International, 2026. DOI: 10.1111/liv.70603
- Newcastle University. LITMUS programme studies, press release, 29 October 2026
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Diagnosis of MASLD and MASH
Further reading
- Fatty Liver Blood Test: Can Blood Tests Catch the Silent Disease?
- GGT test: what your liver enzyme results mean
- Late-Night Eating and Fatty Liver: What the New OHSU Study Found
- Prediabetes Diet and Liver Fat: What a New Trial Found
- How Much Alcohol Is Too Much? What a 2026 Study Found
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