Lab 2 Serum protein Flashcards
What is plasma?
Noncellular component of anticoagulated whole blood
Plasma is essential for transporting nutrients and waste products in the body.
What are plasma proteins?
All proteins of blood plasma and interstitial fluid
These proteins play key roles in maintaining osmotic pressure and immune function.
Which plasma protein is the most abundant?
Albumin
Albumin helps regulate blood volume and pressure.
What are other types of plasma proteins besides albumin?
Immunoglobulins, transport proteins, clotting proteins
These proteins are crucial for immune response and blood coagulation.
Where are most plasma proteins synthesized and catabolized?
In the liver
The liver plays a vital role in protein metabolism.
What primarily consists of total protein?
Albumin and globulins
The balance between these proteins is important for health.
What causes alterations to serum total protein?
↑ or ↓ in volume of plasma water, ↑ or ↓ in concentration of protein in plasma
These changes can result from various physiological and pathological conditions.
What is the reference range for total serum protein?
(65 - 85 g/L)
Values outside this range can indicate health issues.
What does hypoproteinaemia indicate?
Haemodilution
This condition can result from excessive fluid intake or loss of proteins.
What does hyperproteinaemia indicate?
Haemoconcentration
This condition can occur with dehydration or increased protein production.
What are the methods for determining total protein?
- Direct photometric methods
- Biuret method
- Dye-binding methods
- Turbimetric and nephelometric methods
Each method has its specific applications and accuracy levels.
What are the colourimetric methods for total globulin determination?
- Precipitation & biuret
- Specific dyes (e.g. Pyrogallol red) preferentially bind globulins
These methods are useful for quantifying globulin levels in serum.
What is the formula for globulin levels?
Globulin = Total Protein – Albumin
This calculation is preferred for assessing globulin levels.
What is electrophoresis used for?
To determine protein levels in blood
This method separates proteins based on their size and charge.
What are immunochemical methods used for?
Total globulin determination
These methods can provide specific information about different globulin fractions.
What is the most abundant plasma protein?
Albumin
Albumin constitutes about 60% of total plasma protein.
What is the approximate molecular weight of albumin?
≈68kDa
This molecular weight helps in its functions and interactions in the plasma.
What is the reference range for albumin levels in plasma?
(35-50 g/L)
This range is critical for diagnosing hypoalbuminaemia or hyperalbuminaemia.
What percentage of albumin is present in plasma versus ECF?
≈40% in plasma and ≈60% in ECF
This distribution plays a role in fluid balance in the body.
What is the half-life of albumin?
≈18-20 days
This half-life is important for understanding its turnover and effects in the body.
What is the fastest migrating protein in SPEP?
Albumin
This characteristic is used in laboratory diagnostics.
Where is albumin synthesized?
In the liver
Albumin accounts for 25% of total hepatic protein synthesis.
What role does albumin play in transport?
Binds various ligands and acts as a transporter for them
Examples include amino acids, enzymes, bilirubin, hormones, Vitamin D, glucose.
What percentage of the osmotic pressure of human plasma is albumin responsible for?
75-80%
This role is crucial for maintaining blood volume and body fluid distribution.
What condition can hypoalbuminaemia lead to?
Oedema
This occurs due to reduced oncotic pressure.
What are some causes of hypoalbuminaemia?
- Liver cirrhosis
- Nephrotic syndrome
- Malnutrition
- Burns
- Analbuminaemia
Each cause impairs albumin production or increases loss.
What is a potential effect of hypoalbuminaemia related to infection?
Increased infection risk
Albumin helps transport immune molecules, hence its deficiency can impair immune response.
What condition can result from hypoalbuminaemia that affects lipid levels?
Hyperlipidaemia (in nephrotic syndrome)
The liver compensates by producing more lipids in response to low albumin.
What is one of the serious effects of hypoalbuminaemia on the body?
Shock
This occurs due to fluid shifts and hypovolaemia.
What can lead to delayed wound healing in the context of hypoproteinaemia?
Reduced albumin levels
Albumin is essential for tissue repair.
What is a cause of hyperalbuminaemia?
Fluid depletion/dehydration
This condition results in a relative increase in albumin concentration.
What dye-binding method is used for albumin determination?
Bromocresol Green
This method is known to slightly overestimate albumin levels.
What are the main proteins produced in the liver?
- Albumin
- A and B globulins
- A-1-Antitrypsin
- Haptoglobulin
- Transferrin
- C-reactive Protein (CRP)
These proteins play various roles in the body’s physiology.
What role do immunoglobulins play in the body?
Igs play a key role in defence mechanisms of the body
Immunoglobulins are crucial for the immune response.
How many types of immunoglobulins are there?
5 types: IgG, IgA, IgM, IgD, IgE
Each type has distinct functions in the immune system.
In which conditions is the synthesis of gamma globulins increased?
- Chronic infections
- Chronic liver diseases
- Autoimmune diseases
- Leukaemias
- Lymphomas
- Various other malignancies
Increased gamma globulin levels can indicate underlying health issues.
What is hypoalbuminaemia?
A condition characterized by low albumin levels in the blood
It can lead to various health complications.
What is hyperalbuminaemia?
A condition characterized by high albumin levels in the blood
This can also indicate underlying health issues.
What is Multiple Myeloma?
A cancer of the immune system involving β-lymphocyte proliferation (plasma cells)
It is typically a disease of older patients.
What is a characteristic of Multiple Myeloma in terms of immunoglobulin production?
Over-secretion of non-functional immunoglobulin (paraprotein) by cancerous clone
This leads to the presence of monoclonal proteins in the serum.
What are paraproteins?
Identical clones of a single plasma cell
They are referred to as monoclonal because they originate from one clone.
What family of neoplasms does Multiple Myeloma belong to?
Monoclonal gammaopathies
This family includes various disorders related to abnormal plasma cells.
What is a possible cause for low total protein but normal albumin and protein in urine?
Excretion issue
- loss via kidneys
-loss via GI tract (protein losing enteropathy)
Synthesis issue
- chronic liver disease may impair globulin production more than albumin
- immunodeficiency causing low globulin levels
This may indicate excessive protein loss via the kidneys.
What condition is characterized by increased glomerular permeability leading to loss of globulins and other serum proteins rather than albumin?
Nephrotic syndrome
Nephrotic syndrome results in significant proteinuria.
What test can be used to identify which proteins are lost in nephrotic syndrome?
Urine protein electrophoresis test
This test helps determine the specific proteins being excreted.
What tests are performed to check for low globulin levels?
Serum protein electrophoresis
This test evaluates the serum protein levels including globulins.
What tests assess kidney function in the context of nephrotic syndrome?
Kidney function tests (creatinine, eGFR)
These tests evaluate how well the kidneys are filtering blood.
What is a possible cause for low total protein, low albumin, and trace protein in urine?
Malnutrition/Synthesis/Redistribution issue
This may indicate problems with protein synthesis or absorption.
What condition is indicated by decreased albumin levels due to the liver’s inability to synthesize it?
Liver failure (severe cirrhosis/hepatitis)
The liver’s function is crucial for protein synthesis.
What happens to total protein levels in liver failure?
Decreased total protein
This occurs because the liver cannot synthesize any proteins, including immunoglobulins.
What does the absence of proteinuria in liver failure suggest?
Kidney function may still be normal
This indicates that the kidneys are not losing protein.
What symptoms may suggest liver failure?
Jaundice, coagulopathy
These symptoms indicate liver dysfunction.
What are the 4 general causes of low albumin and low total protein?
- Decreased protein production
- Increased protein loss
- Malnutrition
- Redistribution
This condition can lead to various health complications.
How does nephrotic syndrome lead to oedema?
- Damaged glomeruli allow excessive albumin to leak into the urine (proteinuria)
- Low serum albumin reduces oncotic pressure causing fluid to leave capillaries into interstitial space, leading to oedema.
This can cause swelling in various parts of the body.
What is a condition characterized by protein loss through the gut rather than urine?
Protein-losing enteropathy (e.g., Crohn’s disease)
This condition leads to malabsorption and related symptoms.
What symptoms may accompany protein-losing enteropathy?
Diarrhoea, weight loss, vitamin deficiencies
These symptoms are common in gastrointestinal disorders affecting absorption.
Causes of decreased protein production
- Liver disease (cirrhosis/hepatitis)
- Malnutrition / malabsorption (e.g. Crohns disease) - inadequate dietary intake or poor absorption of proteins
- Chronic inflammation (suppresses liver protein synthesis)
Causes of increased protein loss
- Nephrotic syndrome (glomerular damage causes protein loss in urine)
- Protein losing enteropathy (e.g. IBD - protein loss from GI tract)
- Severe burns / extensive skin damage (protein loss through damaged skin).
Further tests to run to investigate the reason behind hypoproteinaemia
- Liver function tests (AST, ALT, ALP, Bilirubin = to assess liver disease)
- Urinalysis + urine protein-to-creatine ratio (to check for nephrotic syndrome)
- Total protein electrophoresis (SPEP = to differentiate between different causes).
- Nutritional assessment (iron studies/vitamin levels = to evaluate malnutrition)
Further investigations to perform if an individual has oedema
- Urine dipstick - to confirm proteinuria
- Serum albumin - to check for hypoalbuminaemia
- Serum creatinine + eGFR - to assess kidney function
- Lipid profile - nephrotic syndrome causes hyperlipidaemia due to liver compensation for protein loss.
