Alcohol-related jaundice Flashcards
What diseases are encompassed by the term alcoholic liver disease?
- alcoholic fatty liver (steatosis)
- alcoholic hepatitis
- cirrhosis
- (risk of hepatocellular carcinoma)
What is considered ‘heavy’ alcohol consumption?
>6 drinks per day on average
What proportion of individuals who consume alcohol heavily will develop alcoholic fatty liver disease?
90%
What proportion of deaths from cirrhosis is alcoholic liver disease thought to account for?
40% (28% of all deaths from liver disease)
What are the 2 broad categories into which the mechanisms underlying alcoholic liver injury can be placed?
- effects of alcohol directly on hepatocytes
- effects mediated by Kupffer cells
What are 5 hepatocyte-specific mechanisms through which alcoholic liver injury is thought to occur?
- the altered redox state induced by alcohol and aldehyde dehydrogenase reactions
- the oxidative stress and lipid peroxidation caused by the induction of CYP2E1 enzymes and the mitochondrial electron transfer system
- the effects of alcohol upon the nuclear transcription factors AMP kinase and SREBP-1c
- protein adduct formation
- altered methionine and folate metabolism with resulting stress on the endoplasmic reticulum
What are 4 stages of Kupffer cell-specific mechanisms through which alcoholic liver injury is thought to occur?
- Chronic alcohol consumption increases gut permeability, and the resulting portal endotoxemia activates Kupffer cells
- Activated Kupffer cells release a number of proinflammatory mediators, incl.:
- tumor necrosis factor-α (TNF-α)
- transforming growth factor-β1
- interleukins 1, 6, 8, and 10
- platelet-derived growth factor
- TNF-α has a plethora of biologic effects and causes hepatocyte apoptosis
- Transforming growth factor-β1 and platelet-derived growth factor play important roles in stellate cell activation, collagen production, and hepatic fibrosis
What are 4 different types of proinflammatory mediators released by Kupffer cells when they’re activated by chronic alcohol consumption?
- tumor necrosis factor-α (TNF-α)
- transforming growth factor-β1
- interleukins 1, 6, 8, and 10
- platelet-derived growth factor.
What is the effect of TNF-alpha when released by Kupffer cells?
hepatocyte apoptosis (and plethora of other biologic effects)
What is the effect of transforming growth factor-beta 1 and platelet-derived growth factor, when released by activated Kupffer cells?
important roles in stellate cell activation, collagen production, and hepatic fibrosis
What are 7 risk factors for alcoholic liver disease?
- Amount of alcohol consumed
- Women at higher risk than men
- Genetic factors
- Spirits and beer higher risk than wine
- Ethnicity e.g. Hispanic / native American
- Obesity
- Protein-calorie malnutrition
What are 4 examples of genetic changes that can predispose to alcoholic liver disease?
- Lipid metabolism: PNPLA3
- Alcohol metabolism: alcohol and aldehyde dehydrogenases
- Cytochrome P-450 enzymes
- Dysregulated cytokine production e.g. TNF-alpha
What are 3 examples of candidate genes for alcohol-related cirrhosis?
PNPLA3, TM6SF2, MBOAT7
What are 6 general clinical manifestations on examination of chronic alcoholism?
- Palmar erythema
- Spider naevi
- Bilateral gynaecomastia
- Testicular atrophy
- Bilateral parotid enlargement
- Dupuytren contracures
What are 6 possible clinical features of alcoholic fatty liver disease?
- Generally asymptomatic
- Anorexia
- Fatigue
- Right upper quadrant discomfort
- Tender hepatomegaly
- Typically do not have jaundice, ascites, or splenomegaly
What are 3 biochemical signs of alcoholic fatty liver disease?
- Macrocytosis
- Elevated AST
- Elevated gamma-GT
How does the presentation of alcoholic hepatitis compare with fatty liver disease?
typically alcoholic hepatitis more dramatic
What are 6 classic features of acute alcoholic hepatitis?
- Severe malaise
- Fatigue
- Anorexia
- Fever
- Protein-calorie malnutrition
- Features of decompensated liver disease
- jaundice
- coagulopathy
- ascites
- encephalopathy
What are 6 typical findings on blood tests in alcoholic hepatitis?
- Leucocytosis with neutrophil predominance
- Macrocytic anaemia
- Thrombocytopenia
- Prolonged prothrombin time
- Raised AST and raised ratio of AST to ALT, ALP, gGT, total bilirubin
- Decreased levels of serum albumin
- Hypokalaemia, hypomagnesaemia, hypocalcaemia, hypophosphataemia