Ch. 7: Clinical Enzymology & Biomarkers of Tissue Injury Flashcards
3 main ways enzymes are used clinically?
1) Diagnosis & prognosis of diseases
2) Analytical reagents: Measure activity of other enzymes/nonenzyme substances in body fluids
3) Therapeutic agents
Difference between serum vs plasma?
Plasma: liquid in which blood cells suspended
Serum = plasma - clotting factors
What processes are plasma specific enzymes involved in?
Blood clotting fibrinolysis complement activation cholinesterase ceruloplasmin
What are non-plasma specific enzymes?
When are they seen? What causes this?
Intracellular enzymes
High turnover, cellular damage, impairment of cells
⬇️O2 supply, infection, toxic chemicals
Acid phosphatase: main tissue source?
Prostate
Alanine aminotransferase: main tissue source?
Liver
Alcohol dehydrogenase: main tissue source?
Liver
Alkaline phosphatase: main tissue sources?
Bone intestinal mucosa hepatobiliary system placenta kidney
Amylase: main tissue sources?
Pancreas
Salivary glands
Arginase: main tissue source?
Liver
Aspartate aminotransferase: main tissue sources?
Heart & skeletal muscle
Liver
Kidney
Brain
Ceruloplasmin: main tissue source?
Liver
Cholinesterase: main tissue source?
Liver
Chymotrypsinogen: main tissue source?
Pancreas
Creatine kinase: main tissue sources?
Skeletal & heart muscle
Brain
Fructose-bisphosphate aldolase: main tissue sources?
Skeletal & heart muscle
Gamma-glutamyl transferase: main tissue sources?
Kidney
Hepatobiliary system
Prostate
Pancreas
Glutamate dehydrogenase: main tissue source?
Liver
Isocitrate dehydrogenase: main tissue source?
Liver
Lactate dehydrogenase: main tissue sources?
Skeletal & heart muscle Liver Kidney RBCs Pancreas Lungs
Leucine aminopeptidase: main tissue sources?
Hepatobiliary system
Intestine
Pancreas
Kidney
Ornithine carbamoyl-transferase: main tissue source?
Liver
Pepsinogen: main tissue source?
Gastric mucosa
Prostatic specific antigen (serine protease): main tissue source?
Prostate
Sorbitol dehydrogenase: main tissue source?
Liver
Triacylglycerol lipase: main tissue source?
Pancreas
Trypsinogen: main tissue source?
Pancreas
What enzymes indicate heart disease? (Old and new)
Old: creatine kinase (CK): CK-MB (CK2)
New: cardiac troponin I
What isoenzyme pattern is found in skeletal muscle?
Creatine kinase (CK): CK-MM (CK3)
How is the rate of an enzyme-catalyze reaction measured?
Measure product formation (via photometric procedures, e.g. spectrophotometer ➡️ NAD+, product of indicator reaction, absorbs light)
Serum markers of acute pancreatitis?
Amylase
Lipase
Trypsinogen
Serum markers of hepatocellular necrosis?
AST
ALT
Serum markers of cholestasis?
Alkaline phosphatase
5’-nucleotidase
Gamma-glutamyl transferase
Where can gallstones occur?
Ampulla of Vater
What is the advantage of using enzymes as analytical reagents?
Specificity & direct measurement of substrate in complex mixture
What monitoring assay procedures are used when enzymes are used as analytical reagents?
ELISA
Describe steps of using enzymes as analytical reagents via specific antibodies absorbed to beads?
1) antibody + bead bind to antigen in test specimen
2) antibody + bead + antigen bind to antibody + enzyme
3) incubate w/substrate & quantitate products ([products directly proportional to [antigen])
Enzyme as reagent: what is the negative reaction for incubating enzyme + hapten w/specimen (w/out hapten)?
Antibody for hapten added ➡️ competes to bind to enzyme + hapten ➡️ inactive enzyme (when substrate added ➡️ no products)
Enzyme as reagent: what is the positive reaction for incubating enzyme + hapten w/specimen (w/hapten)?
Antibody for hapten added ➡️ competes to bind to free hapten ➡️ active enzyme (when substrate added ➡️ products correlated to [free hapten])
Enzyme as reagent: Antibody bind to solid phase + antigen in sample + antigen w/chemiluminescent compound (cc)
If less antigen in sample ➡️ ?
If more antigen in sample ➡️ ?
Less antigen ➡️ more antigen-cc binds to antibody ➡️ more light
More antigen ➡️ less antigen-cc binds antibody ➡️ less light
Enzymes as therapeutic agents: how it is used with bleeding disorders?
Transfusion of fresh blood or its active components
Enzymes as therapeutic agents: oral admin of digestive enzymes in digestive diseases ➡️ example?
Cystic fibrosis
Enzymes as therapeutic agents: admin of fibrinolytic enzyme to recanalize blood vessels occluded by thrombi
What enzyme? Examples of diseases?
Streptokinase
Pulmonary embolism
AMI (acute MI)
Enzymes as therapeutic agents: treating disorders of inborn metabolism & cancer therapy ➡️ examples of each?
Gaucher’s disease: can’t properly bind sugars to phospholipids
L-asparaginase in acute lymphocytic leukemia
