Hepatobiliary Flashcards
Milk thistle MOA?
Silymarin is active extract
antioxidant, free radical scavenger, inhibits lipid peroxidation, retards hepatic collagen formation
What are branch chain AAs?
valine
leucine
isoleucine
SAMe MOA?
hepatoprotectice
antioxidant
antiinflammatory
precursor to glutathione
ALT half life in dogs vs cats?
dog: 17-60 h
cat: 3.5 h
Ursodeoxycholic acid MOA?
antiinflammatory immunomodulation antifibrotic promotes choleresis decreases toxic effects of bile acids
zinc MOA
- essential trace mineral
- enhances ureagenesis
- increased glutathione peroxidase activity
- antifibrotic
Histologic lesion most common for drug/toxin hepatopathy?
centrilobular necrosis
How is ammonia produced?
End product of AA, purine, and amine breakdown by bacteria, metabolism of glutamine by enterocytes, and breakdown of urea by bacterial ureases
Ammonia is rapidly converted to ____ in the liver.
urea or glutamine
What does alkalosis cause with HE?
Pushes NH4+ to NH3 which can diffuse into the CNS
T/F: dogs with chronic hepatitis or more likely to have fever and abdominal pain than dogs with active hepatitis
False- acute is painful with fever, chronic more likely to have ascites
T/F: hepatomegaly is more common in acute hepatitis
True
List some mechanisms (pathophys) of hepatocellular injury
tissue hypoxia, lipid peroxidation, intracellular cofactor depletion, intracellular toxin production, cholestatic injury, endotoxic insults, hepatocyte plasma membrane injury
Why are hepatocytes especially susceptible to anoxia?
liver receives a mixture of venous and arterial blood
what does hypoxic damage to the liver lead to?
plasma membrane and cytosolic organelle injury secondary to ATP depletion; free radicals may cause oxidative cellular injury
how does cholestasis injure the liver?
leads to retention of bile acids that directly damages cellular organelles
how do endotoxins damage the liver?
stimulation of inflammatory cells to produce inflammatory mediators (prostaglandins and leukotrienes) that perpetuate inflammation in the liver; TNFalpha plays an important role as well
how does TNFalpha perpetuate hepatitis?
stimulates hepatocyte apoptosis through the Fas-Fas ligand pathway
Name categories and specific diseases causing hepatitis and cholangiohepatitis in dogs and cats
Idiopathic=canine chronic hepatitis, feline cholangitis complex, nonspecific reactive hepatitis
Viral- adenovirus type I, acidophil cell hepatitis, herpesvirus (neonates), FIP
Bacterial- feline cholangitis complex, Lepto, Bartonellosis, Tyzzer’s dz, Salmonellosis, Listeriosis, Tularemia, Brucellosis, Helicobacter, Septicemia, Mycobacteria
Rickettsial- Ehrlichiosis, RMSF
Protozoal- toxo, neospora, leishmania, cytauxzoonosis, hepatozoonosis, coccidiosis
Parasitic- visceral larval migrans, dirofilariasis, liver fluke migration, schistomiasis, echinoccocus cysts
Fungal- Histo, blasto, coccidioides, aspergillosis, phycomycosis
Algal- protothecosis
Hepatotoxins- acetaminophen, aflatoxin, amiodarone, aspirin, azathioprine, azoles, carprofen, diazepam, halothane, methimazole, lomustine, phenobarb, tetracyclines, TMS, xylitol,, zonisamide
What are the two categories of feline cholangitis complex
neutrophilic vs lymphocytic cholangitis
T/F: neutrophilic cholangitis typically appears histologically as neutrophilic infiltration within the wall or lumen of the intrahepatic bile ducts
True
T/F: lymphocytic cholangitis typically appears histologically as neutrophilic infiltration within the wall or lumen of the intrahepatic bile ducts
False- lymphocytic typically is mixed inflammatory infiltrate (lymphocytes +/- plasma cells) within portal areas, associated with varying degrees of fibrosis and bile duct hyperplasia
What can be seen on histopath with chronic neutrophilic hepatitis that is different from acute neutrophilic hepatitis?
varying degrees of fibrosis and bile duct hyperplasia
What underlying conditions can be associated with neutrophilic cholangitis in cats?
IBD, pancreatitis
T/F: liver sampling is preferred over gallbladder bile for C&S in cats with suspect cholangitis?
false- prefer bile
Prognosis for cats with neutrophilic cholangitis? Possible sequelae?
Good prognosis; bile duct obstruction, acute necrotizing pancreatitis, sepsis, MODS
What is the definitive diagnosis for cats with lymphocytic cholangitis? Treatment?
Diagnose using liver biopsy and immunohistochemical staining; tx involved immunosuppressive glucocorticoid therapy
Canine chronic hepatitis is more common in what breeds?
cocker spaniel, bedlington terrier, dalmation, doberman, labrador, standard poodle, westies
T/F: there is evidence that supports an immune mediated process as perpetuating factor for canine chronic hepatitis?
true
what is common on histopath for canine chronic hepatitis?
lymphocytic/plasmacytic inflammation, occasionally neutrophilic, necrosis/apoptosis, evidence of regeneration, fibrosis or hyperplasia of ductal structures
Mainstay of tx for canine chronic hepatitis?
steroids; also other immunomodulatory drugs (ursodeoxycholic acid, metronidazole, azathioprine, cyclosporine)
Prognosis for dogs with chronic hepatitis?
depends on severity- can be excellent with slow progression or poor once cirrhosis develops
What is the role of copper in canine chronic hepatitis?
Unclear; may have elevated copper levels from cholestasis or elevated copper levels may damage hepatocytes; copper chelation has been shown to improve hepatic pathologic findings
Tx for copper induced hepatitis?
D-penicillamine, trientine, reduced dietary copper
Common histopath findings in nonspecific reactive hepatitis?
widespread inflammatory infiltrates (usually lymphocytes/plasma cells) in portal areas and parenchyma in the absence of hepatocellular necrosis
T/F: viral causes of hepatitis carry a fair to good prognosis?
false- it is poor
Pathogen responsible for infectious canine hepatitis?
adenovirus type I- only seen in young, unvaccinated dogs
Histopath findings for canine adenovirus type I?
large3 basophilic to amphophilic intranuclear inclusion bodies within hepatocytes and Kupffer cells (during 1st week of infection)
T/F: when FIP involves the liver, the disease is uniformly fatal
True
Common serovars of Lepto?
icterohaemorrhagiae, canicola, pomona, hardjo, grippotyphosa, bratislava
Which lepto serovars are more likely to have hepatic involvement?
icterohaemorrhagiae and pomona
How often is the liver involved in Lepto infections?
20-35% of cases; most commonly results in acute renal failure
Other organ systems besides liver and kidney that can be affected by Lepto?
uveitis, acute fever, pulmonary hemorrhage
Which hepatic enzyme is affected most severely with Lepto infections?
ALP