What are the 2 major components of blood? What percentages of blood to the compose?
55% of blood is plasma (liquid phase with dissolved elements)
45% of blood is cells (formed elements)
- 99% erythrocytes (RBC)
- 1% leukocytes (WBC) and thrombocytes (platelets; fragments of megakaryocytes)
What are the functions of the cellular components of blood? (erythrocytes, leukocytes, thrombocytes)
.Major functions of the cells
- Erythrocytes: transport of blood gases
- defense mechanisms (antigens, microbes, parasites), immune response, inflammatory response
- Thrombocytes: blood coagulation
What is plasma? What are the major components of plasma? Give their percentages.
The plasma is the medium in which the blood cells and dissolved components are transported around the body.
Normal blood plasma is 90-92 % water, in which different molecules are suspended.
Dissolved substances include:
electrolytes such as sodium, chlorine, potassium, manganese, and calcium ions
nutrients and waste products
lipoproteins transporting lipids and lipid-soluble molecules hormones (transported by proteins)
plasma proteins (albumin, globulin, fibrinogen, etc) – 98% of total solutes
Out of all of the proteins in plasma, which is the most predominant? What percentage of proteins in plasma does it comprise?
Out of the Proteins:
Albumin – 60%
(Coagulation factors – 4%, All other proteins– 36%)
How is plasma gained? How is serum gained?
Plasma is gained when anti-coagulants are given to the blood
- Plasma = liquid - blood cells
Serum is gained after coagulation, thus serum is fibrinogen-free plasma
- Serum = liquid - blood cells and clotting elements
What are the 2 major types of proteins in plasma? Give examples of each.
How may levels of proteins change in disease?
Where are most plasma proteins synthesized? What protein type is the exception?
Plasma proteins are of two types:
a. those at high concentrations, specific to blood and with a functional role in blood,
- albumin, carrier proteins, immune proteins, proteins of blood coagulation
All plasma proteins, except for the immunoglobulins, are made in the liver.
b. those at low levels, with no functional role in blood.
- proteins that are released from the cells because of normal cell turnover
In disease, there may be an increase or decrease in the levels of resident proteins.
- a. increase or decrease of the protein levels that are specific for blood (e.g. albumin or gamma-globulins)
- b. increased release of intracellular proteins into the plasma, thus increased levels of proteins that normally are in a low concentration in blood (e.g. heart enzyme levels in case of MI).
What is electrophoresis used for?
Electrophoresis is used to:
- identify the presence of abnormal proteins
- to identify the absence of normal proteins
- to determine when different groups of proteins are increased or decreased in serum or plasma
How are proteins separated in electrophoresis?
What are the major peaks in electrophoresis of plasma proteins?
Proteins can be separated based on their net charges. The net charge of the protein depends on its amino acid composition and the pH of the environment. Proteins in which ratio of Lys+Arg/ Glu+Asp is greater than 1 are basic and those less than 1 are acidic proteins. Electrophoresis of serum or plasma is usually done at pH 8.6, at which the proteins are negatively charged and move toward the (+) electrode at a rate dependent on the net charge.
o Major peaks are those of albumin, alpha (alpha1- and alpha2-), beta (can be separated to beta1- and beta 2-) and gamma (gamma1- and gamma2-) globulins.
o Variations in these peaks are indicative of certain diseases, thus change in pattern can be used in diagnosis.
o Usually biuret reaction is used to measure total protein content of plasma, and protein content running under a peak is given as % total protein.
Which peak is the only peak that contains one protein?
What proteins are in the gamma-globulin peak?
Albumin is a peak that composed of albumin only; the other peaks are mixtures of different proteins.
The gamma-globulin peak contains the immunoglobulins.
please see pg 23 of course notes for proteins contained under each peak
Ste the functions of the following proteins and what peak they fall under on electrophoresis:
complement component 3
attached is slide 20 of PP, pg 24 of notes
What is the clinical relevance of low albumin levels?
Name diseases/circumstances under which albumin levels may be decreased.
Albumin: The most abundant plasma protein that makes up 60% of the total protein of the plasma. Its functions are keeping the osmotic pressure of the blood and transporting biomolecules. It transports hydrophobic compounds, e.g. bilirubin, fatty acids, hormones, etc.
Clinical relevance: When albumin level is low, water moves from the arteries to the interstitial space and cannot return to the veins; resulting in edema. Thus, any disease that decreases the levels of albumin in the plasma may result in edema.
Examples of hypoalbuminemia (low albumin level in blood):
In liver disease, associated, for example, with hepatitis C infection, alcoholism, etc, the malfunction will result in diminished production of albumin.
Kwashiorkor disease, protein malnutrition in children, when protein (including essential amino acids) are not taken up in the required concentration, albumin will not be synthesized, thus fluids accumulate in the body, visibly in the limbs and in the abdomen (ascites).
Hypoproteinemia (and hypoalbuminemia) can result from renal disease (albuminura) and from bowel disease (gastroenteropathy).
What is the electrophoretic pattern in the immediate response (acute phase reponse)? In what conditions may this pattern be seen?
Stress or inflammation caused by infection, injury or surgical trauma causes selective increase in plasma proteins, including haptoglobins in the alpha2 mobility band.
Increase of: haptoglobin, alpha-2 macroglobulin, ceruloplasmin, C-reactive protein, complement factors, certain blood clotting factors
Decrease of: albumin, antithrombin, transcortin
RBC lysis --> haptoglobin levels go up. Haptoglobin tremendously increases and runs under alpha 2 peak -->larger peak . Why does CRP not result in larger peak?--> increase in CRP is not enough to increase height of peak
Describe the electrophoretic pattern in the late response (chronic inflammation) and the protein levels responsible for the pattern.
A late response pattern (chronic inflammation) associated with infection shows an increase in the gamma globulin peak due to increase in immunoglobulins. Alpha2 band is also increased and albumin peak is decreased (as in acute phase response).
Note that albumin levels are decreased as a compensatory mechanism to keep total protein levels in the normal range.
What is the electrophoretic pattern for immunosuppressive diseases?
Explain the reason for the changes.
Immunosuppressive diseases cause a decrease in the gamma globulin peak (and an increase in the albumin peak).
congenital: combined immunodeficiency
acquired: primary amyloidosis, lymphoma, nephrotic syndrome
What electrophoretic pattern is seen in hepatic cirrhosis?
Explain the reason for the changes.
Hepatic cirrhosis elevates gamma globulin with reduction in albumin. Albumin is made by the liver, when decreased, gamma globulins are elevated to keep osmotic pressure of the blood close to normal.
Note that alpha and beta peaks also decrease. Also note beta-gamma bridging due to large increase in gamma globulins.
Seen in: cirrhotic liver disease, viral hepatitis, chronic alcohol abuse
What is monoclonal gammopathy? What is the electrophoretic pattern?
What is Bence-Jones protein? Where is this protein detected in monoclonal gammopathy?
Monoclonal gammopathy, due to clonal synthesis of a unique immunoglobulin, results in a sharp increase of the gamma globulin peak. The albumin peak decreases.
In multiple myeloma, neoplastic cells circulate in blood, characterized by uncontrolled proliferation of these WBCs and secretion of a homogeneous gamma globulin, called M-protein. Bence-Jones protein is the overproduced light chain of this gamma globulin that is secreted to the urine.
Multiple myeloma is CRAB: hyperCalcemia, Renal insufficiency, Anemia, Bone lytic lesions/Back pain
Multiple myeloma: Monoclonal M protein spike
see multiple myeloma in first aid
Describe the electrophoretic pattern seen in nephrotic syndrome.
Explain the reason for changes in the pattern.
Nephrotic syndrome shows a reduction in low molecular weight proteins (decreased gamma-globulin peaks) that leave the blood through the kidney. High alpha2 band is present because of inflammation and stress.
Long-term loss of albumin and IgG through kidney.
Describe the electrophoretic pattern seen in protein losing enteropathy.
Explain the reason for changes in the pattern.
Protein-losing enteropathy shows loss of albumin and gamma globulins; slight increase in the alpha2 band is due to a stressful stimulus (same as is seen in acute & late phase response, nephrotic syndrome).