Clin Path Protein Assays

Are protein assays specifically liver function tests?

No but usually those proteins are produced by the liver so it can tell us things about it.

Altered proteins usually tell us about

Disease conditions usually liver and kidneys.

Most commonly performed protein assays in vet med

Total protein, Albumin, Fibrinogen, Globulin

What does plasma protein function with organs cells and tissues?

Helps form structural matrix of all cells, organs, and tissues

What kind of pressure does plasma proteins maintain?

Plasma proteins maintain osmotic pressure

What do proteins serve as in biochemical reactions

PP serve as enzymes for biochemical reactions

What does plasma proteins act as in acid-base balance

Act as buffers in acid-base balance

What do Plasma Proteins do with the Endocrine system?

They serve as hormones

What is plasma proteins function with blood?

Functions in blood coagulation

What do plasma proteins do with pathogenic microorganisms?

Helps defend body against pathogenic microorganisms

What do plasma proteins serve as for most constituents of plasma?

They serve as transport/carrier molecules for most constituents of plasma

Plasma protein includes __

Fibrinogen

Serum protein does not include __

Fibrinogen

TP concentrations are affected by

Altered Hepatic Synthesis, protein distribution, protein breakdown or excretion, dehydration, overhydration.

TP is valuable in determining what patient status?

Hydration status

Dehydration means what for total protein?

Hyperproteinemia (elevated)

Over-hydration means what for TP

Hypoproteinemia (decreased)

Two primary methods for testing TP

Refractometer and Chemistry Panel.

Refractometer testing TP

Estimates the refractive index of serum or plasma. Fast, Inexpensive and accurate.

Chemistry Panel TP testing

Measures the number of molecules containing more than 3 peptide bonds in serum or plasma, used in analytic instruments, simple and accurate.

What is one of the most important proteins in plasma or serum?

Albumin

How much of the Total plasma is made up of Albumin?

35-50%.

Any state of hypoproteinemia is likely caused by

Albumin loss

What cell synthesizes albumin

Hepatocytes.

What can influence Albumin levels?

Any diffuse liver disease, renal disease, dietary intake, and intestinal protein absorption may also influence levels.

What organ should you always look at first when it comes to albumin?

The liver

What is the major binding and transport protein and how?

Albumin, because it maintains osmotic pressure of plasma. Transports Bilirubin, ions, fatty acids, and drugs.

Diseases and conditions associated with alterations in serum protein (INCREASES of things)

Hyperproteinemia and/or hyperalbuminemia, Hemoconcentration, Inflammatory disease, Plasmacytoma, and Lymphoma.

What is Hemoconcentration?

Dehydration

Diseases and conditions associated with alterations in serum protein (DECREASES of things)

Hypoproteinemia and/or hypoalbuminemia, hemodilution, Blood loss, glomerulonephritis, Hepatic insufficiency, Malabsorption, and Malnutrition.

What is Hemodilution?

Overhydration

Globulins

A complex group of proteins.

What are the 3 kinds of globulins?

Alpha, Beta, and Gamma globulins.

Alpha globulins

Synthesized in the liver. Primarily transport and bind proteins. High density and very low-density lipoproteins.

Beta globulins

Responsible for iron transport, heme binding, and fibrin formation/lysis. Includes complement (C3, C4), transferrin, and ferritin.

Gamma Globulins (Immunoglobulins)

Synthesized by plasma cells, responsible for antibody production.

What are the immunoglobins in animals?

Ig-G,D,E,A, and M.

Are globulins usually directly measured?

No it is usually just estimated by the difference between total proteins and albumin concentrations.

How to calculate Globulin?

Total Protein - Albumin = Globulins.

How is the albumin/Globulin ratio calculated?

Dividing the albumin concentration by the globulin concentration.

Albumin/Globulin Ratio alteration indicates what

An alteration in the albumin/globulin ratio is often the first indication of a protein abnormality.

What alters the A/G?

Most pathologic conditions.

A/G ratio in dogs, horses, sheep and goats

Albumin is greater than globulins. Usually greater than 1.0.

A/G ratio in cattle, pigs and cats.

Albumin is equal or lower than globulins. Usually less than 1.0

Which species have an A/G greater than 1.0

Dogs, horses, sheep and goats

Which species have an A/G less than 1.0

Cattle, pigs and cats.

Fibrinogen

Precursor to fibrin

Fibrin

Insoluble protein that forms the matrix of blood clots.

What does decreased fibrinogen levels mean?

Little to no clotting.

Why is fibrinogen not found in serum?

Because it is what forms the matrix of blood clots.

How much of total plasma proteins does fibrinogen make up?

3-6%.

What may elevate fibrinogen levels?

Acute inflammation or tissue damage. They are especially an indication in horses, ruminants and camelids.

Acute phase proteins

Produced by hepatocytes immediately following an injury or inflammation.

What kind of proteins are Albumin and Transferrin?

Negative acute phase proteins because their plasma concentration decreases following injury or inflammation.

30 recognized acute-phase proteins which do we need to know?

SAA, CRP, Fibrinogen, HP, Ceruloplasmin, AGP, MAP.

SAA

Serum Amyloid A

CRP

C-reactive protein

HP

Haptoglobin

AGP

alpha1 Acid Glycoprotein

MAP

Major Acute Phase protein

How are most acute-phase proteins of significance measured?

With immunoasssays.

What is available for measurement of SAA in horses?

A handheld portable analyzer.