Biomarkers Flashcards
What is the rate limiting enzyme in haem synthesis?
ALA synthase (Aminolevulinic acid synthase)
Which enzyme deficiency causes urate overproduction and what condition is it associated with?
HGPRT deficiency
-> Lesh-Nyhan syndrome (self mutiliation, choreiform movements, mental retardation, gout)
Which enzyme marker is raised in Rhabdomyolysis?
CK-MM (creatinine kinase muscle type)
What is amyloid AA associated with?
Chronic inflammation (e.g., rheumatoid arthritis [RA], inflammatory bowel disease [IBD])
Amyloid AL is linked to which condition?
Myeloma amyloidosis
Which enzyme marker is raised in a non-smoker with cirrhosis?
Alpha-1 antitrypsin (A1AT) deficiency
Which enzyme marker is raised in someone with mumps?
Amylase (associated with parotitis)
Which enzyme marker is used to detect gastrointestinal cancers?
Carcinoembryonic antigen (CEA)
What is the order of rise of cardiac markers after a myocardial infarction? (5)
- Myoglobin
- Troponin
- Creatine kinase-myocardial 4. band (CKMB)
- Aspartate transaminase (AST)
- Lactate dehydrogenase (LDH)
What are the characteristics of myoglobin as a cardiac marker?
Rises first but is not specific to cardiac muscle
Peaks at 4-6 hours and declines within 24 hours
What are the key features of troponin as a cardiac marker? (3)
Most sensitive marker of myocardial infarction (not an enzyme)
Rises 4-6 hours post-myocardial infarction, peaks at 12-24 hours
Remains high for 3-10 days
What are the features of creatine kinase-myocardial band (CKMB) as a cardiac marker? (2)
Rises after 6 hours of chest pain onset
Peaks at 12-24 hours and declines within 48 hours
Where is alkaline phosphatase produced? (BLIP)
Liver, bone, placenta, intestines
What are the causes of raised alkaline phosphatase? (4) (in bone, liver, pregnancy, childhood)
Bone: Paget’s disease, osteomalacia, tumors, fractures
Liver: Cholestasis, cirrhosis, infiltrative diseases, hepatitis
Pregnancy (3rd trimester)
Childhood (during growth spurts)
What are the types of creatine kinase and their locations? (3)
Creatine kinase-muscle type (CK-MM): Muscle (95% of CK in plasma)
Creatine kinase-myocardial band (CK-MB): Heart
Creatine kinase-brain band (CK-BB): Brain (very low levels in plasma)