Serum Proteins And Associated Disp4ders

Question 1

What is the blood plasma?

Answer 1

The non-cellular liquid layer of the blood obtained by sedimentation and Centrifugation

Question 2

What is blood serum?

Answer 2

Prepared in laboratory

In the laboratory whole blood is allowed to coagulate before Centrifugation. The resulting fluid is blood serum.
(Blood serum is blood plasma without blood coagulating factors)

Question 3

What is the function of serum protein electrophoresis(SPEP)?

Answer 3

Separates serum proteins regarding their overall charge

This method is often combined with densitometry

Question 4

What are the main serum proteins?

Answer 4

Albumin

a and B globulins

y-globulins

Question 5

What is the function of albumin?

Answer 5

Maintenance of oncotic pressure

Transport: calcium ions, free fatty acids, bilirubin, hormones and drugs

Question 6

What are the functions of a and B globulins?

Answer 6

Enzymes

Transport

Inhibitor proteins

Question 7

What are the functions of y-globulins?

Answer 7

Immune response

Question 8

Where is albumin synth3sized?

Answer 8

Albumin is extremely synthesized in the liver (14 g/day) and is released into the blood

Albumin is small and the most abundant serum protein

Question 9

What is the range of serum albumin?

Answer 9

3.5-5 g/dL

Question 10

Explain the main functions of albumin

Answer 10

1. Maintenance of the osmotic pressure in the blood and prevention of edema
2. Transport of some lipids like free fatty acids, bilirubin, steroid hormones and drugs
3. Binding and transport of ca”chum ions in the blood

Note: Individual”s with congenital analbunemia appear normal and do not show edema. Other serum pr9teins regulate the osmotic pressure early 9n.

Question 11

What are the causes of hypoalbumpnemia?

Answer 11

• Decreased synthesis of albumin

- Increased loss of albumin

Question 12

What are the effects of decreased synthesis of albumin?

Answer 12

Kwashiorkor-dietary deficiency of proteins and often infections

Liver cirrhosis -severe liver damage impairs synthesis of serum proteins

Question 13

What are the effects of increased loss of albumin?

Answer 13

Kidney disease-loss of urine due to damage of glomerulus basement membrane

Severe burns-damage of blood vessels leads t9 huge loss 9f serum

Question 14

What can be used to ind8cate a1 globulin fraction?

Answer 14

1. a1 Antitrypsin (>90%)
2. a Fetotrypsin
3. Transcortin
4. Retinol binding protein

Question 15

What is the clinical significance of a1 antotrypsin (a1-AT)?

Answer 15

1. a1-Antitrypsin is a serum protein released by the liver and inhibits neutrophil e”dataset in lung alveoli
2. A reduced amount of a1-AT in the blood can lead to excessive degradation of elastin in the lung and to emphysema
3. Hereditary deficiency of a1-AT results from a defective hepatic N-glycosylation and reduced release into the blood. This can lead to pulmonary and liver disease

Question 16

How can smoking lead to emohysema?

Answer 16

Smoking activates neutrophils which release neutrophil elastase and at the same time ROS modify the structure of a1-AT and reduce the binding to neutrophil elastase

Elevated neutrophil elastase destroys elastin in the alveoli

Question 17

What 8s the clinical significance of AFP?

Answer 17

AFP is an a1 globulin that is abundant in fetal plasma which has very low levels of albumin. It may have function similar to albumin in fetal life

AFP level is low in healthy adults but it increases in cancer and is used as a serum marker for liver cancer

Question 18

What is the use of maternal AFP?

Answer 18

Maternal serum AFP is used as a marker for possible fetal abnormalities

AFP is mostly found in the amniotic fluid. A small amount of amniotic fluid can cross the placenta and AFP can be measured in maternal serum

High maternal serum AFP level can be an indicator of neural tube defects

Low maternal serum AFP level can be an indicator of Down syndrome

Question 19

What are transcortin and retinol binding protein?

Answer 19

These are a1 globulins that transport specific lipids

Transcortin transports 75% of cortisol in blood

Retinol-binding protein transports retinol in blood from the liver to the peripheral tissues

Question 20

What can be used to indicate a2 globulin fraction?

Answer 20

1. A2 macroglobulin
2. Ceruloplasmin
3. Hepatoglobin

Question 21

What is the significance a2 Macroglobulin?

Answer 21

One of the largest serum proteins

A2M is the major component of the a2 globulin fraction. It has many different functions and inhibits an enormous variety of serum proteases like plasmin (fibrinolysis) and thrombin (coagulation)

A greater than 10 fold increase (abnormal) in blood is often found in patients with Nephrotuc syndrome due to damage of the basement membrane of the glomerulus

The synthesis of a2 macroglobulin is increased and it’s loss into urine is prevented by its large size whereas albumin is very small and lost into urine in nephrotic syndrome

Question 22

What color is ceruloplasmin?

Answer 22

A blue a2 globulin

Question 23

What are the functions if ceruloplasmin?

Answer 23

1. Copper transport in blood

2. Ferroxidase activity

Question 24

Where is ceruloplasmin formed?

Answer 24

Formed in the liver by binding of copper to Apo ceruloplasmin. The released ceruloplasmin transports 95% of copper in blood

Question 25

What is Wilson disease?

Answer 25

Patients with Wilson disease have a very low blood levels of ceruloplasmin as hepatic copper binding is deficient. Apo ceruloplasmin (without copper ) is released into the blood where it is degraded

Question 26

What causes Wilson disease?

Answer 26

Patients have a deficiency of a copper-transporting ATPase (ATPase7-B) which 8s needed to form ceruloplasmin and is also needed for release 9f copper into bile Damage due to copper accumulation in the liver, leakage into the blood and deposits in brain, eyes, kidney and skin. Hepatic dysfunction, neurologically and psychiatric symptoms

Question 27

How does ceruloplasmin impact ferroxidase?

Answer 27

Ceruloplasmin acting as an enzyme needs copper for its ferroxidase activity Ferroxidase forms ferric ion Macrophages degrade heme and release ferrous ion which could lead to radical formation (Fenton reaction) This is prevented by ceruloplasmin which forms ferric ion that can be bound to transferrin and transported in blood

Question 28

What is Haptoglobin?

Answer 28

An a2 globulin that binds to free hemoglobin dimers in the blood and prevents loss of Hb in urine

Question 29

What is the functioning 9f haptoglobin?

Answer 29

Haptoglobulin-hemoglobin complex is taken up by macrophages. This explains why acute hemolysis l3ads to a low serum level 9f free haptoglobin Serum protein electrophoresis is used to monitor the progress in patients with hemolytic anemia

Question 30

What is transferrin?

Answer 30

Transferrin 8s a B-globulin which transports ferric ion in blood between: intestine, liver, bone marrow and spleen Transferrin can bind two Fe3+ atoms for transport (Normally the transferrin binding sites are not all filled with iron)

Question 31

What are the clinical evaluations of transferrin?

Answer 31

Low transferrin saturation is found in patients with iron deficiency as fewer sites of transferrin are filled High transferrin saturation is found in patients with iron overload (High serum iron leads to increased binding)

Question 32

What is hemopoxin?

Answer 32

Is a B-globulin that binds to free heme in the blood and prevents the loss of heme iron

Question 33

What happens heme-hemopoxin?

Answer 33

Taken up into heoat9cytesvand the iron is bound to the storage protein ferritin Hemopoxin prevents: A. Heme-induced damage of plasma membranes (heme insertion and ROS) B. Heme usage by microbes: heme is an important source of iron for pathogenic m8croorgabisms

Question 34

How do LDL separate in SPEP?

Answer 34

They separate with B-globulins LDLs have only apo-B100 which has an overall positive charge LDL are also named B-lipoproteins

Question 35

What are y-globulin synthesized by?

Answer 35

Plasma cells/activated B cells

Question 36

What’s the origin of IgM?

Answer 36

Is found in blood and lymph and it 8s first antibody to be produced in response to an antigen (infection)

Question 37

What are the origins of IgG?

Answer 37

Smallest and most common- found in all body fluids. It is produced By repeated exposure to the same antigen. IgG can cross the placenta giving passive immunity to the fetus and new born

Question 38

What are the origins of IgE?

Answer 38

Is found in the lung, skin, mucous membranes and secreted in allergic reactions

Question 39

Where is IgA found?

Answer 39

Found in body secretions and protects body surfaces. It is the main antibody found in human milk

Question 40

What is the role of IgD?

Answer 40

Uncertain

Question 41

What is the impact of serum protein electrophoresis in multiple myeloma?

Answer 41

Multiple myeloma is a tumor of the plasma cells and is an example of monoclonal gammopathyb It is characterized by the presence 9f high amounts 9f a single type of immunoglobin produced by a malignant clone of the cell Serum protein electrophoresis is an important tool that helps in diagnosis and monitoring patientswith multiple myeloma

Question 42

What is an acute phase reaction of the liver?

Answer 42

Leases to changes in the synthesis 9f serum proteins ``` The hepatic acute phase reaction is an overall positive response to prevent damage following an injury such as in: Infections Extreme stress Burns Major crush injury Allergy or other ```

Question 43

How can acute phase reactants be subdivided?

Answer 43

Into positive and negative reactants depending on the amounts synthesized

Question 44

What are the positive reactants of acute phase ?

Answer 44

Serum proteins that are synthesized in larger amount as they reduce inflammation and deprive microbes of iron. ``` Examples: a1-antitrypsin Ceruloplasmin Haptoglobin Hemopoxin ```

Question 45

What are the negative acute phase reactants?

Answer 45

Serum proteins that are synthesized in smaller amount in order to preserve amino acids for the increased synthesis of positive acute phase reactants ``` Examples: Albumin Transcortin Retinol-binding protein Transferrin ```

Question 46

What is special about C-reactive protein?

Answer 46

It is an acute phase reactant that does not lead to a peak in SPEP

Question 47

Where is C-reactive protein (CRP)?

Answer 47

Is synthesized and released during inflammation and was first found in blood of patients with acute inflammation. CRP was named after the fact that it reacted with the C-polypeptide of pneumococcus CRP can increase to 30,000 times of its normal level There is a specific test for CRP and it is used to monitor the proces of inflammation, trauma and infection