Chemical Pathology 15 - Enzymes and cardiac markers Flashcards
What is the Km?
Michaelis Mentin constant
= concentration of substrate at which the reaction velocity is 50% of maximum
What tumour marker can be used for germ cell, ovarian and testicular malignancies?
ALP
When is ALP elevated physiologically?
In pregnancy and childhood
Recall 4 pathologies that can cause a raised ALP
- Bile duct pathology (eg cholestatic liver disease)
- Bone pathology (fracture/ metabolic bone disease)
- Germ cell tumours
- Intestinal pathology (but not routinely used for investigation of bowel disorders)
Which LFT enzyme is most specific to liver pathology?
ALT
How can hepatic and biliary disease be best distinguished on the LFTs?
ALT:ALP ratio
If ALT much higher than ALP = hepatic
How many isoenzymes of LDH exist?
5
Recall 3 things that a raised LDH may indicate
- Haemolytic anaemia
- Tumour marker (lymphoma, germ cell testicular Ca)
- Myositis (rheum)
Which enzyme is markedly raised in acute pancreatitis?
Serum amylase
What is the most likely cause of a raised CK-MB1?
Rhabdomyolysis (history of long lie/ big fall?)
Where is CK-MB1 vs CK-MB2 produced?
CK-MB1 - skeletal muscle
CK-MB2 - cardiac muscle
In which population is CK physiologically slightly raised?
Afrocaribbean
Which prescription drug may be the cause of a raised CK-MB1?
Statins (as they can cause myopathy)
When does troponin I peak following chest pain?
2-4 hours
Within what time period does troponin I return to normal following a cardiac event?
5-10 days