Liver Diseases 1 Flashcards
Trachea
- Cartilage plates & smooth muscle
- Respiratory epithelium
- Submucosal glands
Bronchi
- Cartilage foci & smooth muscle
- Respiratory epithelium
- Submucosal glands
Bronchioles
- No cartilage, thinner muscular layer
- Simple ciliated epithelium
- Clara cells
the main function of the liver
→ synthesis and metabolism of carbohydrate, lipids, protein and drugs
→ metabolism and excretion of bilirubin and bile acids
major primary liver diseases
→ viral hepatitis
→ alcohol liver diseases
→ non-alcoholic fatty liver diseases
→ nonalcoholic fatty liver disease
→ hepatocellular carcinoma
major causes of liver disease
(west and east)
→ in the west = alcohol and hepatitis C virus
→ elsewhere = hepatitis B virus, but the incidence is decreasing (vaccination)
two facts about the liver
- dual supply of blood vessels
- vulnerability to a wide variety of insults → metabolic, toxic, microbial, circulatory and neoplastic
What is another name for jaundice?
icterus
What are the symptoms of jaundice?
yellow sclerae and skin
Serum bilirubin in jaundice patients
> 10 micromole
What is pre-jundice?
haemolytic jaudice
What is non-haemolytic jaundice?
congenital hyperbilirubinaemias
What are the three types of jaundice?
- haemolytic jaudice - pre-hepatic
- congenital hyperbilirubinaemias - non-haemolytic
- cholestatic jaundice
Haemolytic Jaundice (Pre-Hepatic)
increased breakdown of RBC
Investigation of Haemolytic Jaundice
- haemolysis
- increase serum unconjugated bilirubin
- normal alkaline phosphatase (ALP) and transferase
Congenital Hyperbilirubinaemias
- most common - Gilbert’s syndome
- decreased UDP-glucuronyl transferase activity
- decreased conjugation of bilirubin with glucuronic acid
- unconjugared bilirubin increases and other tests are normal
What are the two types of chlostatisis?
intrahepatic cholestatsis
extrahepatic cholestasis
intrahepatic cholestatsis
- abnormal bile excretion
- bile channel obstruction
extrahepatic cholestasis
bile flow obstruction - distal to the bile canaliculi
How do you investigate cholestatic jaundice?
- serum liver biochemistry - jaudice (conjugated bilirubin)
Hepatitis Pathology
liver cell necrosis and inflammatory infiltration
Hepatitis Presentation
- enlarged and tender liver (+/)
- jaundice (+/-)
Hepatitis Investigation
serum transferase increases etc.
Hepatitis types
acute and chronic
Causes of acute hepatitis
- viruses = hepatitis viruses
- non-viral infections - toxoplasma gondii etc.
- alcohol
- drugs - anti-TB (isoniazid)
- others - pregnancy etc
Clinical Features of acute hepatitis
- usually (viral) self-limiting, return to normal structure and function
- occasionally profession into massive liver necrosis and even death
Investigation of acute hepatitis
- increased serum ALT (best indicator of acute hepatic injury)
- prothrombin time and bilirubin (reflect disease severity)
Chronic Hepatitis
a sustained inflammatory disease
Causes of chronic hepatitis
- viral
- chemical
- autoimmune
How long does chronic hepatitis last?
more than 6 months
What is Hepatitis A?
acute viral hepatitis
How is acute viral hepatitis spread?
faecal-oral
how does acute viral hepatitis damage the liver?
cytopathic and immunity-mediated by t cells
acute viral hepatitis virus
HAV
Clinical Features of Hepatitis A
relatively short incubation period, non-specific symptoms - flu-like
Hepatitis A signs
- jaundice +/-
- hepatomegaly - moderate
- spleen palpable
lab testing of Hepatitis A
serum transferase increases
Hepatitis A characteristics
Acute, self-limiting; no chronic stage - fulminant hepatitis, rare
Hepatitis A management
- no specific treatment
- Prophylaxis - immunisation
active Hepatitis A vaccine
inactive strain
inactive Hepatitis A vaccine
immunoglobulin
Hepatitis B Epidemiology
worldwide, prevalent in parts of Africa, middle and far east
Hepatitis B virus
HBV, DNA virus
HBV Protein
core - protein of core particle
pre-core - pre-core/core cleaves to HBeAg
surface - envelope protein; HBsAg; basis of current vaccine
Spread of Hepatitis B
- parenteral
- close personal contact
- vertical
Hepatitis B - Mechanism of Liver Damage
immunity-mediated by t-cells
Clinical Features of Hepatitis B
- long incubation period
- chronic carriers - HBsAg >6mo ; HBeAg or viral DNA - highly infectious, risk of chronic hepatitis and cirrhosis
- chronic hepatitis - 3-5% acute hep B, serum liver biochemistry abnormal; liver biopsy/histology: mild inflammatory changes to cirrhosis
Hepatitis B Treatment
- antiviral agents with indications eg serum HBsAg, HBV DNA
- Prophylaxis → avoid high-risk factors, immunisation: active (vaccine) and passive
Hepatitis C viruses
HCV; non-A, non-B
Hepatitis C spread
blood or blood products, other routes eg. vertical but rare
Hepatitis C mechanisms of liver damage
immunity mediate by t-cells
Hepatitis C Special Clinical Features
- short incubation
- 60-90% becoming carriers
- high risk of developing → chronic, active hepatitis cirrhosis, hepatocellular carcinoma
Hepatitis C Diagnosis
by exclusion
Management of Hepatitis C
- interferon used in acute cases to prevent chronic diseases
- needle-stick injuries must be followed and treated early
Prophylaxis
HCV is a RNA virus; a rapid change in envelope proteins hence vaccine is difficult
