Clinical Biochemistry Flashcards
Clinical biochemistry
Analysis of samples of bodily fluids and used results to clarify a clinical picture
Plasma vs serum
Serum contains no clotting factors and therefore doesn’t clot!
How is serum produced?
Plasma is placed into a glass tube (negatively charged) or a serum activator gel (allows better separation from clotted cells) this causes it to clot. This clot is centrifuged, the supernatant is serum.
What is the difference between an analytical and preanalytical error?
Preanalytical - sample collection, handling, submission. Analytical - methodology, interference
What is the function of lipoproteins?
Transport of H2O insoluble lipids in circulation
What makes up a chylomicron?
Triglycerides in a thin protein and phospholipid layer. They are 90% dietry TG, 5% cholesterol, apoproteins, phospholipids.
Where are chylomicrons produced? How do they circulate?
Produced by enterocytes and released into central lacteal, these drain into the thoracic duct and move to peripheral circulation and adipose for storage.
What is the fate of chylomicrons?
They are degraded by lipoprotein lipase found on the endothelial wall of blood vessel, triglycerides are absorbed and the chylomicron remnant moves to the liver for degradation.
What is the function of VLDLs?
Exports liver triglycerides to the peripheral tissues.
Outline the fate of VLDL.
Hepatic lipoprotein lipase forms the VLDL, they are transported out of the liver towards the peripheral tissues. LPL breaks down the VLDL resulting in FFA and MG and a remnant LDL.
What proportions of the VLDL are TG and cholesterol/apoproteins?
60% TG 17% Cholesterol and apoproteins
What proportions of the LDL are TG and cholesterol/apoproteins?
60% cholesterol 10% TG
What is the function of the LDL?
Transports cholesterol to the peripheral tissues
What is the function of the HDL?
Pick up cholesterol from peripheral tissues
Where are HDLs formed?
Liver and intestinal epithelium
Define lipaemia of the plasma.
Increased chylomicron and VLDL (NOT CHOLESTEROL) in the plasma causes the plasma to be opaque. Remember to fast animals before taking samples for 12-24 hours.
Where can lipases be found in the body?
Gastric, pancreatic, endothelial (lpl), hepatic, hormone sensitive, lysosomal
Outline the chylomicron test.
Which of these pictures indicates chylomicron increase in the sample?

Refrigerate blood sample overnight, if a lipid layer forms on top = exogenous lipids (chylomicrons), if no separation occurs = endogenous lipids are present (VLDL)
B = Increased chylomicrons only
D = Increased VLDL only
What does increased triglycerides in a fasted blood sample mean? (x7 DDx.)
Post-prendial (meal), endocrine disease, pancreatitis, liver disease, steroid administration, nephrotic syndrome, LPL deficiency
Hyperlipidaemia
Increased cholesterol
What can hypercholesterolemia indicate? (x6 DDx.)
Diet, endocrine disease (hypothyroidism), hepatic disease, nephrotic syndrome, steroids, primary lipid metabolism (Schnauzers)
What can hypocholesterolemia indicate? (x2)
Dietary influence, decreased hepatic syndrome
What is the function of Albumin?
A carrier protein (bilirubin, fatty acids, calcium, hormones and drugs), maintenance of oncotic pressure
Half life of albumin in the dog and horse.
Dog - 8 days Horse - 20 days
How can total globulins be measured?
Total protein - albumin = total globulin
This process separates proteins based upon electrical charge and molecule size.
Serum protein electrophoresis.
Describe the serum protein electrophoresis curve.
Albumin - single sharp peak Globulin - a1, a2, b1, b2, y - hundreds of peaks in 3-5 regions
Dysproteinaemia
Abnormal protein concentration
DDx. hyperalbuminaemia
Dehydration, shock, erythrocytosis
DDx hyperglobinaemia
Infection, inflammation, near-term pregnancy,
Describe the serum protein electrophoresis graph for a monoclonal gammopathy. What are the DDx?
Narrow based gamma peak - neoplastic (b cell, plasma cell), non-neoplastic (E. canis)
Describe the serum protein electrophoresis graph for a polyclonal gammopathy. What are the DDx?
Broad based gamma peak - inflammation, immune mediated disease, liver disease
Causes of hypofibrinogenaemia.
Decreased synthesis - hepatic disease, afibrinogenaemia. Increased consumption - DIC, fibrinogenolysis
Plasma cell tumour
Myeloma
What are positive acute phase proteins?
Positive acute phase proteins increase with tissue injury, they increase within hours (max 2 days).
Examples of a1 globulin PAPP’s
a1 antitrypsin - protease inhibitor, a1 acid glycoprotein
Examples of a2 globulin PAPP’s
Ceruloplasmin - Cu transporter Haptoglobin - bind free Hb Serum amyloid A
Serum protein electrophoresis peaks for FIP
a2 globulin peak, not specific
Examples of b globulin PAPP’s
C3 and C4 Fibrinogen - only in plasma C-reactive protein - CRP Ferritin - iron storage Occasionally IgM and IgA
Examples of negative acute phase proteins.
Albumin, transferrin
What are negative acute phase proteins?
Negative acute phase proteins decrease with tissue injury, they increase within 5-7 days. Eg dog = 7d, horse = 21d
DDx. Panhypoproteinaemia
Acute haemorrhage (anaemia), GI loss (bowel disease - protein-losing-enteropathy), inflammation exudate.
DDx. Hypoalbuminaemia
Decreased production - hepatic disease, malnutrition, maldigestion (pancreatic enzyme deficiency). Increased loss - kidney leakage (protein-losing-nephropathy), GI loss, burns
DDx. Hypoglobinaemia
Failure of passive transfer, combined immunodeficiency
The concurrent findings of erythrocytosis and hyperproteinaemia are most likely due to:
- Dehydration
- Splenic contraction
- Chronic inflammation
- Primary erythrocytosis
- B-lymphocyte neoplasia
2
The concurrent findings of a regenerative anemia and hypoproteinaemia are most likely due to
- Acute hemorrhage
- Chronic renal disease
- Chronic inflammation
- Extravascular hemolysis
- Generalized marrow hypoplasia
4
The concurrent findings of a nonregenerative anemia and hyperfibrinogenemia are most likely due to:
- Dehydration
- Hepatic failure
- Inflammation < 1 week duration
- Inflammation > 1 week duration
- Disseminated intravascular coagulopathy
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