11.3 - Liver Flashcards
what protein carries unconjugated bilirubin to the liver?
albumin
what enzyme conjugates bilirubin?
uridine glucuronyl transferase (UGT)
what converts conjugated bilirubin to urobilinogen?
intestinal flora
intestinal flora convert conjugated bilirubin to _____________
urobilinogen
what happens to urobilinogen after being converted from conjugated bilirubin by intestinal flora?
oxidized to stercobilin and urobilin
- dark urine due to increased urine urobilinogen
- increased risk for pigmented bilirubin gall stones
extravascular hemolysis or ineffective erythropoiesis
what is the etiology of extravascular hemolysis or ineffective erythropoiesis?
high levels of UCB overwhelm the conjugating ability of the liver
what is the what is the lab finding in extravascular hemolysis or ineffective erythropoiesis?
increased UCB
what does phototherapy do for neonatal jaundice?
makes UCB more soluble (does NOT conjugate it)
what is the etiology of physiologic jaundice of the newborn?
newborn liver has transiently low UGT activity
what is the lab finding in physiologic jaundice of the newborn?
increased UCB
jaundice during stress (infection), otherwise not clinically significant
gilbert syndrome
what is the etiology of gilbert syndrome? what is the inheritance?
- mildly low UGT activity
- AR
what is the lab finding in gilbert syndrome?
increased UCB
presents with kernicterus, usually fatal
crigler najjar syndrome
what is the etiology of crigler najjar syndrome?
absence of UGT
what is the lab finding in crigler najjar syndrome?
increased UCB
black / dark liver, otherwise not clinically significant
dubin-johnson syndrome
what is the etiology of dubin-johnson syndrome? what is the inheritance?
- deficiency of bilirubin canalicular transport protein
- AR
what is the lab finding in dubin-johnson syndrome?
increased CB
- dark urine
- pale stool
- pruritis
- hypercholesterolemia with xanthomas
- steatorrhea with malabsorption of fat soluble vitamins
biliary tract obstruction (obstructive jaundice)
what is the etiology of obstructive jaundice?
associated with gall stones, pancreatic carcinoma, cholangiocarcinoma, parasites, liver fluke
what are the lab findings in biliary tract obstruction?
- increased CB
- decreased urine urobilinogen
- increased alk phos
- dark urine
- urine urobilinogen normal or decreased
viral hepatitis
what are the lab findings in viral hepatitis?
increase in both CB and UCB
an increase in both CB and UCB should make you think of what etiology for dark urine?
viral hepatitis
what hepatitis antigen signifies infectivity?
HBeAg
what is the only marker seen during the window period of HBV?
HBcAb (IgM)
the inflammation in viral hepatitis predominantly involves what structure(s)?
portal tract
what is cirrhosis?
end stage liver damage characterized by disruption of the normal hepatic parenchyma by bands of fibrosis and regenerative nodules of hepatocytes
the fibrosis in hepatitis is mediated by __________, which comes from _________
TGF-B from stellate cells
the degree of deficiency of clotting factors in hepatitis is followed by measuring what parameter?
PT
what molecule mediates the damage of alcohol related liver disease?
acetaldehyde
what is the histological appearance of alcohol related liver disease?
swelling of hepatocytes with formation of Mallory bodies
what are mallory bodies composed of? in which condition are they seen?
- damaged cytokeratin filaments
- alcohol related liver disease
where is AST located within hepatocytes?
mitochondria
what is the ALT : AST ratio in nonalcoholic fatty liver disease?
ALT greater than AST
tissue damage in hemochromatosis is mediated by ___________
free radicals
what is the inheritance of hemochromatosis?
AR
primary hemochromatosis is due to mutations in what gene?
HFE
what is the triad for hemochromatosis?
- cirrhosis
- secondary DM
- bronze skin
what are the labs in hemochromatosis?
- increased ferritin
- low TIBC
- high serum iron
- high % sat
what does biopsy show for hemochromatosis?
accumulation of brown pigment in hepatocytes
what is the treatment for hemochromatosis?
phlebotomy
wilson disease is due to a mutation in what gene?
ATP7B
wilson disease presents in childhood with:
- cirrhosis
- neuro manifestations (behavior, dementia, chorea, parkinsonian symptoms)
- kayser fleisher rings in cornea
where does copper accumulate in the brain of patients with wilson disease?
basal ganglia
what are the labs for wilson disease?
- high urine copper
- low serum Cp
- high copper on liver biopsy
what is the treatment for wilson disease?
D-penicillamine (chelator)
what auto antibody is present in primary biliary cirrhosis?
AMA
primary biliary cirrhosis is an autoimmune granulomatous destruction of ___________ (intrahepatic / extrahepatic) bile ducts
intrahepatic
primary sclerosing cholangitis is inflammation and fibrosis of __________ (intrahepatic / extrahepatic / both) bile ducts
both
onion skin appearance - which biliary condition? what is the cause?
- primary sclerosing cholangitis
- periductal fibrosis
“beads on a string” - which biliary condition?
primary sclerosing cholangitis
primary sclerosing cholangitis is associated with what colon disease?
UC
what autoantibody is present in primary sclerosing cholangitis?
p-ANCA
how does reye syndrome present?
- hypoglycemia
- elevated liver enzymes
- N / V
- possible coma and death
which liver tumor is associated with contraceptive use?
hepatic adenoma
subcapsular liver tumor that carries a risk of rupture and intraperitoneal bleeding; grow with exposure to estrogen
hepatic adenoma
aflatoxins from aspergillus can cause ____________ (cancer type) due to induction of _________ mutations
- hepatocellular carcinoma
- p53
hepatocellular carcinoma carries an increased risk for what syndrome?
budd chiari syndrome
what is budd chiari syndrome? how does it present?
- liver infarction due to hepatic vein obstruction
- painful hepatomegaly and ascites
what is the serum tumor marker for HCC?
AFP
what are the most common sources for metastatic HCC?
- colon
- pancreas
- lung
- breast
