Chempath 23: Enzymes And Cardiac Markers Flashcards
Which 2 organs are most commonly associated with ALP rise in case of pathology ?
Liver
Bone
When does bone release excess ALP ?
In pathologically high Osteoblast activity
How can you differentiate if the pathology is in the liver or Bone when ALP is high?
Measure GGT. If also high it suggests that the liver has the pathology.
List 2 physiological causes of high ALP ?
Pregnancy (ALP is released by the placenta)
Growth spurts in children (bone)
Which 2 bone diseases produce a high ALP (> 5X upper limit) ?
Osteomalacia
Paget’s disease
List 2 pathologies of the liver that cause a high ALP (> 5X upper limit) ?
Cholestasis
Cirrhosis
Which of these causes a high ALP but not more than 5X the upper limit ?
A) Bone fracture B) Osteomyelitis C) Hepatitis D) Bone tumours E) Alcoholic Liver Cirrhosis
E) Alcoholic liver cirrhosis
Cirrhosis of the liver causes a high ALP > 5X the upper limit
The rest are all causes of a high ALP but < 5X the upper limit
Which test would you do to confirm acute pancreatitis ?
Serum Amylase (10x upper limit) Pancreatic Lipase
(salivary glands also produce an amylase isoenzyme - can be raised in parotitis)
Which disease that is normally vaccinated against can cause a high Amylase?
Mumps
Causes parotid swelling (parotitis) which releases amylase
Which form of Creatine kinase is specific for the heart ?
CK-MB
Which form of Creatine kinase is specific for skeletal muscle?Which one is specific for the brain ?
CK-MM
CK-BB
Which drug used in treatment of cardiovascular disease can causes myalgia or even Rhabdomyelisis and also raised creatine kinase?
Statins
How many hours post MI do troponins start to rise?
4-6 hours
They peak at 12-24 hours and remain elevated for 3-10 days
Are cardiac markers used to influence decisions about thrombolysis ?
No they are too slow to rise
List 2 cardiac markers that are useful in heart failure ?
ANP (from the atria)
BNP (from the ventricles)
List 3 enzymes that are biomarkers for MI ?
Myoglobin
Troponin (best markers)
CK-MB
Which enzyme cardiac biomarker rises earliest after an MI ?
Myoglobin
But not very specific
Which biomarker is most useful to detect re-infarction after a very recent MI.
CKMB
Which liver enzyme is raised in an MI ?
AST
Where are most enzymes found
Intracellularly
In what order are enzymes released
Cytosolic then sub-cellular
Where is alkaline phosphatase found in high concentrations
Liver
Bone
Intestines
Placenta
What pathologies cause a rise in ALP <5x the upper limit
Bone - tumours, fractures, osteomyelitis
Liver - infiltrative disease, hepatitis
RF for statin-related myopathy
polypharmacy (esp fibrates, cyclosporin) high dose genetic predisposition previous hx of myopathy associated with other statins vitamin D deficiency
What are other causes of raised CK
muscle damage myopathy (DMD) MI severe exercise physiological (Afro-caribbeans)
When would you measure TPMT activity
before starting patients on a thiopurine ( azothioprine, 6-MP)
marker of therapeutic response/drug toxicity
Where are different cardiac enzymes found
Myoglobin - cytosolic
CK-MB - mitochondria and nucleus
Troponins - contractile apparatus
What is the diagnostic criteria for MI
Either: - Rise and fall of troponin or more rapid rise and fall of CK-MB and at least one of... - Ischaemic symptoms - Pathological Q waves on ECG - ECG changes indicative of ischaemia - Coronary artery intervention OR - Pathological findings of an acute MI
Define one international unit (U) of enzyme activity
the quantity of enzyme that catalyses the reaction of 1 micromol of substrate per minute
