Lecture 9 9/12/24

Question 1

What is the most abundant component of plasma?

Answer 1

protein

Question 2

What are the functions of plasma proteins?

Answer 2

-blood coagulation
-maintaining oncotic pressure
-host defense
-transport of substances
-regulation of cellular metabolism

Question 3

What are the two major categories of plasma proteins?

Answer 3

-albumin
-globulins

Question 4

What are the characteristics of albumin?

Answer 4

-one of the smallest proteins
-single most abundant protein
-synthesized in the liver
-accounts for 75% of colloidal osmotic pressure
-carrier molecule, especially for calcium

Question 5

Which proteins are included as globulins?

Answer 5

-immunoglobulins
-acute phase proteins
-complement proteins
-lipoproteins

Question 6

What are the characteristics of globulins?

Answer 6

-all non-albumin proteins
-typically combined with other substances
-mostly synthesized by liver
-immunoglobulins are secreted by plasma and B cells

Question 7

What are the characteristics of acute phase proteins?

Answer 7

-change in conc. by >25% in response to inflammatory cytokines
-increase in conc. if they are positive acute phase proteins
-decrease in conc. if they are negative acute phase proteins

Question 8

What is the major negative APP?

Answer 8

albumin

Question 9

What is the major positive APP in dogs and pigs?

Answer 9

C reactive protein

Question 10

What is the major positive APP in cats and horses?

Answer 10

serum amyloid A

Question 11

What is the major positive APP in ruminants?

Answer 11

haptoglobin

Question 12

What are the characteristics of the acute phase response?

Answer 12

-positive APPs increase and decrease quickly
-positive APPs typically increase prior to presence of inflammatory leukogram and persist until inflammation resolves

Question 13

What are the characteristics of plasma?

Answer 13

-liquid portion of unclotted blood
-contains all proteins
-must be collected with anticoagulant

Question 14

What are the characteristics of serum?

Answer 14

-liquid portion of clotted blood
-contains all proteins except fibrinogen

Question 15

What are the characteristics of total protein refractometry?

Answer 15

-estimation of protein in plasma
-expressed as a concentration (g/dL)
-reported as part of CBC
-light refraction is proportional to solids in solution

Question 16

What is the assumption made with TP refractometry?

Answer 16

the concentrations of glucose, electrolytes, urea, and lipids are normal

Question 17

What are the interferences for TP refractometry?

Answer 17

-hyperglycemia
-increased urea
-hypercholesterolemia
-lipemia
-excess EDTA in blood

Question 18

How do hyperbilirubinemia and hemolysis impact TP refractometry?

Answer 18

make the demarcation difficult to read

Question 19

What are the characteristics of fibrinogen by heat precipitation?

Answer 19

-crude measurement used in large animal
-detects hyperfibrinogenemia only
-more sensitive to inflammation than leukogram changes
-reported on CBC
-take the measurement from pre-heating and subtract measurement from post-heating

Question 20

What are the characteristics of TP via spectrophotometry?

Answer 20

-reported on chem profile
-expressed as concentration (g/dL)
-not sensitive enough for low protein fluids
-does not account for fibrinogen unless heparinized plasma is used

Question 21

How is albumin typically measured?

Answer 21

via spectrophotometry that is reported on the chem profile

Question 22

How are globulins reported on the chem profile?

Answer 22

indirect calculation using TP - albumin

Question 23

What are the characteristics of fractionate globulins?

Answer 23

-identified via protein electrophoresis
-indicated when patient has moderate to marked hyperglobulinemia
-determines inflammatory response vs neoplasia

Question 24

What are the principles of protein electrophoresis?

Answer 24

-separates proteins by size, shape, and charge
-area under each peak is proportional to the % of the fraction in serum
-numerical results provide absolute values for each fraction
-must examine the gel tracing for interpretation

Question 25

What is dysproteinemia?

Answer 25

presence of normal protein at abnormal concentration

Question 26

What are the mechanisms of dysproteinemia?

Answer 26

-relative/shifting of water -decreased production -increased production -loss

Question 27

How does a nonselective dysproteinemia differ from a selective dysproteinemia?

Answer 27

-nonselective: both albumin and globulin are affected in the same direction -selective: only albumin or globulin is affected or both are affected in opposite directions

Question 28

What are the characteristics of nonselective hyperproteinemia?

Answer 28

-most common cause is concurrent increase in albumin and globulin due to dehydration -typically accompanied by increased HCT -relative increase due to water loss

Question 29

What are the general characteristics of nonselective hypoproteinemia?

Answer 29

-often caused by overhydration or hemodilution -can be caused by IV fluid administration or edematous disorders

Question 30

What are the characteristics of nonselective hypoproteinemia caused by protein losing enteropathy?

Answer 30

-intestinal disease prohibits absorption or transport of proteins, resulting in loss in the feces -hypoproteinemia occurs when rate of protein loss exceeds ability of liver and B cells to produce proteins

Question 31

What are the characteristics of nonselective hypoproteinemia caused by effusive disease?

Answer 31

-vasculitis results in extravasation of proteins into interstitial space -pleuritis and peritonitis lead to extravasation of proteins into pleural and peritoneal cavities

Question 32

What are the characteristics of nonselective hypoproteinemia caused by protein losing dermatopathy?

Answer 32

-thermal or chemical burn can result in plasma proteins oozing out of vessels -globulins may increase with inflammation

Question 33

What are the potential causes of hypoalbuminemia due to decreased production?

Answer 33

-inflammation -hepatic failure -starvation/cachexia

Question 34

What are the potential causes of hypoalbuminemia due to increased loss?

Answer 34

-protein losing nephropathy -GI parasites

Question 35

What are the characteristics of hypoalbuminemia due to inflammation?

Answer 35

-albumin is major negative acute phase protein -increased production of positive APPs requires decreased albumin production to conserve amino acids -often accompanied by increased globulins -may be accompanied by inflammatory leukogram -most common dysproteinemia

Question 36

What are the characteristics of hypoalbuminemia due to hepatic insufficiency?

Answer 36

-must lose 50-80% of liver function -albumin and globulin production decrease, but immunoglobulin production can keep globulin values normal -other signs of hepatic insufficiency present

Question 37

What are the characteristics of hypoalbuminemia due to starvation?

Answer 37

-starvation or cachectic states result in decreased nutrient intake and increased protein degradation -hypoproteinemia due to low albumin only

Question 38

What are the characteristics of hypoalbuminemia due to protein-losing nephropathy?

Answer 38

-albumin is small enough to pass through damaged glomerular membranes -will see proteinuria and increased urine protein: creatinine ratio -hypoglobulinemia can occur in severe cases -may see other evidence of renal insufficiency

Question 39

What are the characteristics of hypoglobulinemia?

Answer 39

-typically caused by decreased immunoglobulins -often due to failure of transfer of passive immunity or immune deficiency

Question 40

What are the characteristics of hyperglobulinemia?

Answer 40

caused by chronic antigenic stimulation or B-lymphocyte neoplasia

Question 41

Which fraction do the positive acute phase proteins migrate to during acute inflammation?

Answer 41

alpha2 fraction

Question 42

What are the characteristics of polyclonal gammopathy?

Answer 42

-broad-based peaks in beta and gamma globulins -secondary to prolonged antigenic stimulation -concurrent hypoalbuminemia is common

Question 43

What are the characteristics of monoclonal gammopathy?

Answer 43

-tall narrow peak in beta or gamma fraction -immunoglobulin secreted by neoplastic proliferation of B cell or plasma cell (multiple myeloma, extra-medullary plasmacytoma) -some diseases can mimic monoclonal gammopathy (Ehrlichia)

Question 44

What are the characteristics of nonselective hypoproteinemia caused by blood loss?

Answer 44

-hemorrhage results in blood volume loss -compensatory fluid shifts from extravascular to intravascular space -hemodilution causes hypoproteinemia and anemia