Block 5: PSC, NAFLD, Cirrhosis Flashcards
Diagnosis of NAFLD
- Raised ALT and/or GGT and evidence of steatosis on imaging
- Imaging evidence of steatosis
- Raised ALT and/or GGT and evidence of insulin resistance / central obesity / metabolic risk factors
- No history of excess alcohol (<14/21units/week), no known pre-existing liver disease, no hepatotoxic drugs, Negative blood screen for other liver disease (viral, autoimmune)
- Liver biopsy if diagnostic uncertainty
Liver enzymes and NAFLD
- Most common liver enzyme abnormality is raised GGT
- ALT in the normal range in up to 80%
- “Typical” abnormality is raised ALT and/or GGT
- ALT typically falls with advanced fibrosis and advancing age (ALT > AST → ALT < AST)
- We should not use liver enzymes to identify/diagnose patients with NAFLD as can be normal
- Can have raised IgA and raised ferritin with normal transferrin saturation
Staging of NAFLD
- Stage of liver fibrosis: fibrosis is the only indicator of prognosis
- Steatosis vs NASH (steatosis + inflammation)
- Liver biopsy is the gold standard for staging
Some tests for liver fibrosis
- Blood tests: FIB-4 score (NAFLD), NAFLD fibrosis score, ELF score (NAFLD), Fibrotest, ProC3
- Imaging: Transient elastography (probs that shoots a wave through the liver, detector measures elasticity. Stiffness corelates to fibrosis- non invasive), Acoustic force radiation imaging (ARFI), MR elastography
- AST/ALT ratio >0.8 is suggestive of advanced fibrosis
Determining staging of NAFLD
- Suspect NAFLD: calculate FIB-4 score
- If FIB-4 score >1.3 in under 65 and more than 2 in over 65 then do Transient elastography (TE).
- If TE <8kpa its low risk NAFLD
- If TE >8kpa then consider liver biopsy
Types of NAFLD
- F0-1 (low risk NAFLD): primary care, lifestyle advice, treat metabolic risk. Re-assess FIB-4/TE in 3 years
- F2-3: Lifestyle advice, treat metabolic risk. NAFLD directed surgery. If non-diabetic vitamin E. If diabetic include GLP-1 or Pioglitazone or Empaglitazone. Clinical trial
- F4: lifestyle advice, treat metabolic risk. NAFLD directed therapy. HCC + varices screen. Bone density assessment
Management of NAFLD
- Weight loss >10%: VLCD, Orlistat, meal replacement
- Healthy diet (Mediterranean diet is recommended)
- Exercise: reduces steatosis and hepatic inflammation. Improves metabolic profile. Moderate intensity, high intensity and resistance exercise
- Avoid/limit alcohol intake, Stop smoking
- Control of diabetes, blood pressure and cholesterol
- Refer patients withliver fibrosisto a liver specialist (indicated by scoring system)
- Bariatric surgery: caution in cirrhosis. Improvement in steatosis, steatohepatitis and fibrosis
- Specialist management may includevitamin E,pioglitazone,bariatric surgeryandliver transplantation
Practical tips for NAFLD
- Explain that NAFLD is reversible with lifestyle change
- Set achievable weight loss goals
- Regular meal plan, reduce snacking, portion control
- Count daily calories, use a pedometer/activity tracker
- Sign post to exercise schemes, community gym, weight management programmes, walking groups
NAFLD: treatment for cardiovascular risk
- T2DM: Metformin (reduce HCC risk), Pioglitazone and Liraglutide- slows fibrosis progression, Empagliflozin (reduce steatosis)
- Hypertension: ARB’s, ACEi as anti-fibrotic
- Dyslipidaemia: assess QRISK3, Statins are safe in NAFLD and hepatoxicity is rare
- Look for sleep apnoea and treat
- Smoking cessation
Specific liver treatment in NAFLD
- Vitamin E: for NASH with stage F3, assess ALT after 6 months
- Pioglitazone: side effects are weight gain, increased bladder cancer risk, reduced bone density. Not widely used in non diabetic NASH
- Liraglutide (GLP1 analogue): NASH with diabetes, causes weight loss
Monitoring for NAFLD
- Every 3 years
- FIB-4 or NFS is effective for those with a low score to begin with
- For those with an increased FIB4/NFS (but low fibroscan): follow up with the fibroscan is needed
Cirrhosis: pathophysiology
Due to chronic inflammation and damage to liver cells. Functional liver cells are replaced with scar tissue (fibrosis). Nodules of scar tissue form within the liver, separated by fibrous tissue.
Normal liver → Steatosis → Steatohepatitis → Fibrosis/cirrhosis
Causes of cirrhosis
- Alcohol-related liver disease
- Non-alcoholic fatty liver disease (NAFLD)
- Hepatitis B
- Hepatitis C
- Rare: autoimmune hepatitis, Primary biliary cirrhosis, Haemochromatosis, Wilsons disease, Alpha-1 antitrypsin deficiency, cystic fibrosis, Drugs (amiodarone, methotrexate and sodium valproate)
Assessing severity of cirrhosis
- Childs-Pugh score
- MELD score: bilirubin, INR and creatinine. For end stage liver disease
- UKELD score: sodium, bilirubin, creatinine, INR: have to get a minimum score to be considered for liver transplantation in the UK
Stages of cirrhosis
- Stage 1: compensated with no varices or ascites
- Stage 2: compensated with varices but no ascites
- Stage 3: variceal bleeding without any other complication
- Stage 4: Non-bleeding decompensation i.e. ascites, HE, jaundice
- Stage 5: any second decompensating event
Decompensated cirrhosis
- Deterioration in liver function
- Manifests as jaundice, increasing ascites, hepatic encephalopathy, renal impairement/hypovolaemia, signs of sepsis
- May be precipitated by: GI bleeding, infection/sepsis, alcoholic excess, Drugs (opiates, NSAID’s), development of HCC, portal vein thrombosus, dehydration, constipation
Ascites
- Commonest complication of cirrhosis
- Abdo distension/shifting dullness
- Radiological detection (US) before clinical
- Can be treated with diuretics but eventually is resistant
- Cirrhosis causes increased intrahepatic vascular resistance and portal blood flow, causing portal hypertension. There is renal sodium retention causing overload of lymphatics and ascites
Ascites
- Commonest complication of cirrhosis
- Abdo distension/shifting dullness
- Radiological detection (US) before clinical
- Can be treated with diuretics but eventually is resistant
- Cirrhosis causes increased intrahepatic vascular resistance and portal blood flow, causing portal hypertension. There is renal sodium retention causing overload of lymphatics and ascites
Ascitic fluid analysis
- Diagnostic paracentesis: required at onset of new ascites and in all hospitalised patients
- SAAG: Albumin (serum) - Albumin (ascites)
- If >11g/l ascites is usually due to portal hypertension
- Ascites is most commonly but not exclusively caused by cirrhosis
Spontaneous bacterial peritonitis
- Infection of the ascitic fluid in the absence of a secondary cause, diagnose by fluid analysis
- Most common organism: E.coli and Klebsiella pneumoniae
- Usually asymptomatic: fevers, abdo pain, renal impairement
- Polymorphonuclear cells >250/mm in ascitic fluid or Neutrophil 0.25 x10^9 on automated testing
- Treat with antibiotics according to sensitivities (co-amoxiclav or ciprofloxacin)