Serina Farzin-Nasab, MD Emory University Family Medicine Residency Program
Dec 14, 2015
Serina Farzin-Nasab, MDEmory UniversityFamily Medicine Residency Program
3 Categories:
1- Direct hepatocellular damage (transaminases)
2-Cholestasis ( bilirubin, alkaline phosphates)
3-Liver’s synthetic ability ( albumin, PT)
Transaminitis
Hepatocyte necrosis leads to leakage of enzyme
Hepatitis Toxic injury Ischemic injury
Hep C: liver cell death by apoptosis (programmed cell death) and by necrosis
1/3 pt’s with Hep C have persistently normal
serum transaminases
Levels of aminotransferases can rise in Severe muscular exertion or other muscle injuries, polymyositis
Hypothyroidism
AST and ALT levels do not follow a normal bell-shaped distribution
AST and ALT are higher in
obese pt’s, males and nonwhites ( blacks and Hispanics)
Causes of Elevated ALT or AST Values in Asymptomatic Patients
A) Autoimmune hepatitis
B) Hepatitis B
C) Hepatitis C
D) Drugs or toxins
E) Ethanol
F) Fatty liver
G) Growths (tumors)
H) Hemodynamic disorder (congestive heart failure)
I) Iron (hemochromatosis), copper (Wilson's disease) or alpha1-antitrypsin deficiency
M) Muscle injury
Typical AST or ALT Values in Disease
Cholestasis reflected in abnormal bilirubin and AP levels
In acute bile duct obstruction from a gallstone,
AST and ALT levels often reach 500 U per L or more in the first hours , whereas AP and GGT levels can take several days to rise.
MARKERS OF CHOLESTASIS
Elevation of GGT alone results from enzyme induction by alcohol or aromatic medicatios
GGT is elevated in persons who drink 3 or more per day
Direct/conjugated hyperbilirubinemia
Conjugated bilirubin levels do not rise until the liver has lost approximately half of its excretory ability.
The presence of conjugated bilirubin in the urine ( urine dipstick), is always indicative of hepatobiliary disease .
Indirect/uncongealed Hyperbilirubinemia:
Gilbert syndrome
Common benign inherited disorder
Levels between 2 and 3 mg/d
Patients develop detectable jaundice during acute illness or starvation
Hemolysis
Confirmed by an elevated retic count & increased haptoglobin levels.
In adults, no serious liver disease will
cause elevation of indirect bili alone without a concurrent rise in direct bili levels.
AP
Elevated levels are found in adolescents, children (secondary to bone growth), and pregnant women
Women with persistently elevated AP levels
primary biliary cirrhosis Confirmed by a serum antimitochondrial antibody
test
Hepatic Cause of elevated AP
Hepatocellular disease (usually <3-fold increase)
• Alcoholic hepatitis• Viral hepatitis• Fatty infiltration of liver• Cirrhosis
Hepatic Cause of elevated AP
Obstructive processes (usually >3-fold increase)
Choledocholithiasis Cancer of head of pancreas Cholangiocarcinoma Cholestatic hepatitis
Hepatic Cause of elevated AP
Infiltrative, neoplastic, Primary or metastatic carcinomas (15- to 20-fold increase)
Primary biliary cirrhosis Amyloidosis Hepatic congestion caused by heart disease Infectious mononucleosis
Hepatic Cause of elevated AP
Medications:CaptoprilErythromycinGold salts PhenothiazinesTrimethoprimand-sulfamethoxazoleAnticonvulsants
Increased synthesis of AP in Diabetes mellitus 44% of patients with DM have increased AP
Common Non hepatic Causes of Elevated GGT
Acetaminophen overdose Acute myocardial infarction Acute pancreatitis Anticonvulsants (phenytoin, phenobarbital, carbamazepine)
Brain tumor Diabetes mellitus Hyperthyroidism Infectious mononucleosis Epilepsy
Albumin
An Index of liver synthetic capacity Low albumin level and no other LFT abnormalities are likely to have a non hepatic
cause
Albumin
Non hepatic causes of low Albumin: Inflammatory states such as burns,
trauma,& sepsis Active rheumatic disorders Severe end-stage malnutrition Pregnancy Proteinuria
PT Does not become abnormal until more
than 80%of liver synthetic capacity is lost
Useful to be followed in acute hepatic failure
(Factor 7 has very short half life)
PT
Vitamin K deficiency Chronic cholestasis or fat malabsorption A trial of vitamin K injections ( 5 mg /day SQ x 3
days) practical way to exclude vitamin K deficiency
PT should improve within a few days
Ammonia Concentrations are much higher in the brain than
in the blood and therefore do not correlate well
It is not unusual for the blood ammonia to be
normal in a patient who is in a coma from hepatic encephalopathy.
QUIZ
Other than hepatitis, causes of elevatedserum GGT include all of the following
except:
A. Diabetes mellitus.B. Hypothyroidism.C. Brain tumor.D. Infectious mononucleosis.E. Acute myocardial infarction
Answer : B
Hyperthyroidism is associated with
elevated GTT
QUIZ
The greatest increase in serum alkalinephosphatase is generally seen in a
patientwith which of the following conditions?
A. Primary biliary cirrhosis.B. Alcoholic hepatitis.C. Viral hepatitis.D. Fatty infiltration of the liver.E. Cancer of the head of the pancreas
Answer: A
Primary billiary cirrhosis
QUIZ
In patients with viral hepatitis, the serum AST level is usually higher than the serum ALT level
A. True.
B. False
False
QUIZ
Normally, most of the total bilirubin is conjugated.
A. True
B. False
False
70% of total Billi is non conjugated