Proteins Flashcards
What proteins are in the plasma?
Albumin and globulins (including fibrinogen and clotting factors)
Is fibrinogen in serum?
No
What are most of the plasma proteins synthesized by?
Hepatocytes
What do proteins contribute to?
Colloid oncotic pressure to help maintain intravascular volume
What is protein dyscrasia?
Presence of abnormal protein
What is dysproteinemia?
Presence of normal proteins at abnormal concentration
What is nonselective hyperproteinemia?
All protein concentrations are increased
What is selective hyperproteinemia?
Total protein concentration is increased and some protein concentrations are increased more than others
What is nonselective hypoproteinemia?
Total protein concentration is decreased and all proteins are decreased
What is selective hypoproteinemia?
Total protein concentration is decreased and some protein concentrations are decreased more than others
How do you determine if dysproteinemia is selective or nonselective?
Serum electrophoresis
What is the most common cause of dysproteinemia?
Other than dehydration, inflammation
What are the 3 groups of proteins whose plasma concentrations change during inflammation?
Positive Acute Phase Proteins
Negative APP
Delayed response proteins
How can you analyze total protein?
Refractometer
How does a refractometer work?
The degree of water refraction in a solution is proportional to the quantity of solids
How does a colorimetric work?
The amount of color change is proportional to the amount of protein
How do you analyze the albumin concentration?
BCG dye binding reaction: colorimetric
How do you determine the globulin concentration?
Total protein - albumin
How does serum protein electrophoresis work?
Migration through an acetate cellulose or agarose gel towards the anode
Separate in 4-6 groups of one or more bands
What is the most common cause of hyperproteinemia?
Hemoconcentration
Inflammation is a common cause, but it does not always cause it
What is hemoconcentration caused by?
Loss of plasma H2O
How does B-lymphocyte neoplasia cause increased protein synthesis?
B-lymphocytes may produce immunoglobulin
When do hypoproteinemia occur?
When the remaining blood is diluted
What are causes of increased loss from vascular space?
Blood loss Protein Losing Nephropathy Protein losing enteropathy Protein losing dermopathy Plasma loss
What are the lab findings associated with protein losing nephropathy?
Proteinuria, mostly albuminruia
Hypoproteinemia and hypoalbuminemia
Possible renal failure
Possible hypercholsterolemia
What are the lab findings associated with protein losing enteropathy?
Hypoproteinemia
What are the lab findings associated with protein losing dermopathy?
Nonselective hypoproteinemia
What are the lab findings associated with plasma loss?
Nonselective hypoproteinemia
What is hypoproteinemia?
Decreased synthesis and/or increased catabolism
What are causes of hypoproteinemia?
Hepatic insufficiency Malabsorption or maldigestion Cachectic states Lymphoid hypoplasia/aplasia Failure of passive transfer Hemodilution
What are causes of hyperalbuminemia?
Hemoconcentration (dehydration; decreased ECF)
Induced synthesis by glucocorticoid therapy
Falsely increased using BCG method
What is the most common cause of hyperalbuminemia?
Hemoconcentration
What are causes of hypoalbuminemia along with hyperproteinemia?
Inflammatory
Concurrent to B lymphocytes neoplasia
What are causes of hypoalbuminemia along with hypoproteinemia?
Decreased production or loss or both
What does hyperglobulinemia frequently occur with?
Hyperproteinemia, but it is possible with normoproteinemia due to hypoalbuminemia
What are common causes of hyperglobulinemia?
Hemoconcentration
Inflammation
B lymphocyte neoplasia
What is hypoglobulinemia commonly with?
Hypoproteinemia and occasionally with normoproteinemia
What are the 2 main causes of hypoglobulinemia?
Decreased production
Loss
What can increase APPs?
Any injury that causes inflammation (infectious or noninfectious)
Why do you use positive acute phase proteins for evaluation?
Insensitivity of other tests
They provide another method of monitoring inflammation
What is fibrinogen?
Plasma protein produced by hepatocytes
Used for production of fibrin by thrombin
What are causes of hyperfibrinogenemia?
Hemoconcentration
Inflammation
What is the plasma protein to fibrinogen ratio (PP:F)?
Ratio to help differentiate hyperfibrinogenemia of inflammation from hemoconcentration
What is the PP:F for cattle?
> 15 likely dehydration; <10 likely inflammation
What is the PP:F for horses?
> 20 likely dehydration; <15 likely inflammation
What will dehydration do to APPs?
Increase all proteins at the same degree
What will inflammation do to APPs?
increases fibrinogen and other proteins but will also decrease some proteins
What samples are preferred for APPs other than fibrinogen?
Serum
What APPs use special tests?
Serum C-reactive protein Haptoglobin Serum Amyloid A a1-Acid glycoprotein Ceruloplasmin Ferritin
What is the most common reason to measure Ig?
Determine passive transfer from mares to foals and cows to calves
What is failure of passive transfer?
Placentation in horses and calves prevents in utero transfer of Ig
How do foals and calves obtain maternal Ig?
They need to ingest colostrum soon after parturition
What is Ig uptake mediated by?
Fc receptor on epithelial cells
What are causes of FPT?
Lack of colostrum intake
Inadequate IgG in the colostrum
Failure to absorb and potentially due to different haplotypes of Fc receptors in calves
What is considered adequate passive transfer in foals?
IgG >800 mg/dL
What is considered complete FPT in foals?
IgG <200 mg/dL
What is considered partial FPT in foals?
IgG <800 mg/dL and >200mg/dL
What is considered adequate passive transfer for calves?
IgG > 1000-1600 mg/dL
What is considered complete FPT in calves?
IgG < 500-800 mg/dL
What is considered partial FPT in calves?
IgG <1600 mg/dL and >800 mg/dL
What are ways to test for FPT?
Radial immune diffusion (most used)
Glutaraldehyde coagulation test
Latex agglutination
