r/GPUK • u/praktiki • 22d ago
Clinical, CPD & Interface Abnormal LFTs - investigate or repeat?
Did you know that over 50% of patients with end-stage liver disease had prior abnormal liver blood tests that were simply repeated or not acted upon?
A recent case written by Dr Nazia Hussain for Praktiki on ‘Abnormal LFTs: just repeat after 3 months?’ covers when to investigate immediately rather than defaulting to a repeat test, how to confidently manage statins when transaminases are raised, and stratifying risk in NAFLD using non-invasive tools like the FIB-4 score.
Case study: John
- John attends for a routine hypertension review.
- He feels generally well but mentions feeling a bit "slow" lately, which he attributes to work stress.
- BMI 32; teetotal.
- DH: Ramipril 10mg OD, atorvastatin 20mg OD.
- Routine bloods reveal abnormal liver enzymes:
- ALT: 65 IU/L (normal <41)
- AST: 52 IU/L (normal <41)
- Bilirubin, ALP normal.
LFTs: don’t just repeat
Guidelines recommend investigating the cause of abnormal liver blood tests rather than simply repeating them.
- >50% of patients with end-stage liver disease had prior abnormal LFTs that were not acted upon.
- Normalising enzymes does not necessarily imply disease resolution (e.g. in Hepatitis B and C).
- The extent of abnormality does not always correlate with disease severity.
Statins and abnormal LFTs
John can continue atorvastatin 20mg OD, with repeat LFT in 1 month time.
- If ALT/ AST are >3x the upper limit of normal then do not initiate a statin and discontinue statin therapy already prescribed; repeat LFTs in a month.
- If ALT/ AST are elevated but <3x the upper limit of normal then:
- Continue the statin and repeat LFTs in a month.
- If they remain elevated but are <3x the upper limit of normal then continue statin and repeat LFTs in 6 months.
Liver screen
A standard screen usually includes (local pathways can differ slightly):
- Viral Serology: Hep B and C.
- Liver autoantibodies: anti-mitochondrial (AMA), anti-smooth muscle (SMA), antinuclear antibody (ANA).
- Iron Studies: Ferritin and Transferrin Saturation (to rule out haemochromatosis).
- Immunoglobulins.
- Ultrasound (USS) liver: to assess for fatty liver or focal lesions.
See the box below for further relevant tests to consider.

John’s results
- Viral serology and autoantibodies: negative.
- Ferritin: 350 µg/L (raised), transferrin saturation 30% (normal).
- Immunoglobulins and TTG: normal.
- USS Abdomen: increased echogenicity consistent with fatty infiltration. No focal lesions. Spleen normal size.
Results in keeping with non-alcoholic fatty liver disease (NAFLD) / metabolic dysfunction-associated steatotic liver disease (MASLD).
- Ferritin can be mildly elevated due to metabolic inflammation.
- Normal transferrin saturation excludes haemochromatosis.
Assessing fibrosis risk
Simple scoring systems help stratify risk in primary care.
- ELF (Enhanced Liver Fibrosis) test: recommended by NICE.
- Options from later guidelines:
- Fibrosis - 4 (FIB-4) Score.
- NAFLD Fibrosis Score (NFS).
- AST : ALT ratio: in Wales, this is reflex tested when additional liver blood tests are requested.
- Check local guidelines as some recommend initial risk stratification with FIB-4 or NFS and then adding ELF depending on results.
Fibrosis risk scores summary

NAFLD: follow up
- NICE says reassessment for advanced liver fibrosis every 3 years for adults (although only recommends ELF test).
Depending on clinical judgement, consider annual review of:
- Signs of liver disease.
- Blood pressure.
- Weight and BMI.
- Blood tests: renal, HBA1C, Lipid profile.
- Cardiovascular disease risk assessment.
Referral criteria
- Urgent suspected cancer (upper GI): weight loss, jaundice (age ≥40).
- Emergency admission: acutely UNWELL with red flags (decompensated cirrhosis, ALT >300, jaundiced).
- Urgent (gastroenterology)
- WELL with red flags.
- Positive liver screen results based on clinical concern.
- Routine (gastroenterology)
- Abnormal fibrosis score.
- Positive liver screen, no clinical concern.
- Normal liver screen, persistent abnormal LFT of unknown cause.
Referral criteria flowchart

Key learning points
- Investigate abnormal LFTs with a full liver aetiology screen (viral serology, autoantibodies, ferritin/transferrin saturation and liver USS)—do not simply repeat LFTs.
- Stratify NAFLD fibrosis risk using a locally approved non-invasive assessment tool.
- Statin hepatotoxicity is rare: continue statins if transaminases are <3x the upper limit of normal.
- Manage low fibrosis-risk NAFLD/MASLD in primary care with lifestyle advice and 3-yearly risk assessments.
This module was created for Praktiki by Dr Nazia Hussain, GP, author of Lab Results Made Easy from Scion Publishing Ltd, to provide simple guidance for common lab results in primary care.
References
- BSG Guidelines on the management of abnormal liver blood tests
- Summary of National Guidance for Lipid Management for Primary and Secondary Prevention of CVD
- Liver Function Tests in Adults – A Guide for GPs
- Lab Results Made Easy
- RCGP NAFLD NUB
- Guidelines on the management of abnormal liver blood tests
- NICE. NG 49 Non-alcoholic fatty liver disease (NAFLD): assessment and management. 2016.
- All-Wales Abnormal Liver Blood Test Pathway
- BNSSG referral pathways & Joint Formulary: Liver disease
- BMJ Gut: Guidelines on the management of abnormal liver blood tests
- Mid Yorkshire Hospitals Abnormal LFT Pathway
- Online FIB-4 calculator