RBC morphology and Blood groups

what are the types of erythron pools?

1. bone marrow 2. blood 3. spleen/tissue

what is the function of RBC in bone marrow?

Erythropoiesis

what is the function of RBC in blood?

deliver oxygen

what is the function of RBC in spleen/tissue?

Remove aged cells

CFU-E

specific to erythirin line in bone marrow

what is transferrin?

transport protein for iron in the bloodstream into tissues or storage

what is transferrin the result of?

apotransferrin binding to iron

what does ferritin bind to in bone marrow?

rubricyte

what is the function of ferritin in bone marrow?

move rubricyte to blood to be incorporated into hemoglobin

apotransferrin

a molecule in which most iron in blood will be bound to

Hemosiderin and ferritin

stored in bone marrow, spleen, and liver to act as storage iron; small amounts may be released into tissues

Hypoferremia

Decrease in concentration of iron in serum or plasma

what will you look at on a panel to determine hypoferremia?

serum Fe

Hypoferritinemia

Increase in concentration of ferritin in serum or plasma

what will you look at on a panel to determine hypoferritinemia?

Serum Ferritin

Hyperferritinemia

Increase in concentration of ferritin in serum or plasma

what will you look on a panel to determine hyperferritinemia?

Increase in concentration of ferritin in serum or plasma

what are the two potential pathogenesis for hypoferremia?

1. persistent low-grade blood loss 2. persistent inflammatory disease

where is persistent low-grade blood loss located?

usually located in intestine or skin

what is the morphology of mammalian RBCs?

1. annucleate 2. equal spacing from one another 3. anaerobic metabolism 4. biconclave shape 5. central pallor

what does the high surface: volume ratio in RBC allow?

allows cell to transport more oxygen

what does the shape of RBC allow for?

allows alteration of morphology in blood vessels

besides RBC surface, what else can glycolipids and glycoproteins attach to?

platelets and leukocytes

what species have RBC exceptions and what are they?

J-group (bovine) , R-group (ovine) , and A/O-group in pigs → antigen located in plasma, only in high concentrations will they attach to RBC membrane

what size RBC do canines have?

large RBC

what is the MCV of canine RBC?

77 fL

what is the size of RBC in blood for canines?

Isocytosis; same size RBC in blood

do canine RBC have a central pallor?

Prominent central pallor

what is the lifespan of a canine RBC?

in circulation for ~ 120 days

what do most canine RBC lack?

alloantibodies

DEA

Dog Erythrocyte antigen

which DEAs are MOST antigenic?

positive form 1.1 → should be avoided in blood transfusions; 1.2 also antigen but less then + 1.1

what are the other blood groups in dogs?

DEA 3,4,5,7,and DAL

what DEAs are the universal donors in dogs?

+4 and -1.1 dogs

which breed is the best donor in dogs?

Greyhounds best donors as they have higher RBC mass so they can replenish their own supply quickly

what are the size of feline RBC?

small RBC

what is the MCV of feline RBC?

55 fL

what is the variation of feline RBC in blood?

Mild variation in size

describe the central pallor in feline RBC

Central Pallor not prominent

what is the lifespan of RBC in felines?

In circulation ~ 75 days

what are the blood groups in felines?

AB system: A,B, AB blood groups (A most common)

what is important to know with feline blood types?

Have naturally occurring antibodies

in felines, Type A have…

low titer anti-B hemagglutinins and hemolysins

in felines, type B have…

Type B cats have high titer anti-A hemagglutinins and hemolysins

why might a kitten result in severe hemolysis?

NI in "A-kittens ' that feed on colostrum from "B-cats " will have severe hemolysis

what does it mean if a cat has "Mik" in terms of blood?

agglutinates all blood antigens (A,B, AB)

what does "low titer anti-B hemagglutinins and hemolysins" mean?

they have a small amount of antibodies that can clump (agglutinate) and potentially destroy (hemolyze) red blood cells with the B antigen, which is present in type B blood

what is the size of RBC in equine?

small

what is the MCV of RBC in equine?

47 fL

do equines have central pallor?

No, Rouleaux formation (stack like a coin)

what is the lifespan of RBC in equine?

Circulate ~ 160 days

what is important about RBC in bone marrow of equine?

Immature RBC rarely released into blood → difficult to determine regenerative and degenerative anemia

how many blood antigens can horses have?

32-34 antigens

how many blood groups are there in horses?

7 blood groups

which blood groups are the most immunogenic in horses? (EA= erythrocyte antigen)

EAA and EAQ

what are the other blood groups of horses?

EAC, EAD, EAK, EAP, EAU

what is good to know about thoroughbreds and their blood type?

most thoroughbred horses are Aa+ NI occurs

what is the size of RBC in bovine?

medium RBC

what is the MCV of bovine?

60 fL

what is the shape of RBC in ruminants?

Mild variation in size and shape

what is the lifespan of RBC in bovine?

Circulate ~ 140 days

how many genetic systems for blood are recognized in bovine?

11

what is the most important blood group in bovine?

EAJ system→ freely circulating and soluble in plasma; attaches to RBCs at high concentrations

what other blood groups are important in bovine and why?

A and F involved in erythrocyte lysis; if animal has been vaccinated against Babesia and anaplasma this can occur

what is the size and shape of RBC in exotics?

large Elliptical cells (younger will be more rounded)

what are the important differences in RBC in exotic animals?

1. nucleated 2. aerobic metabolism

do exotic RBC have central pallor?

Not biconcave so lack central pallor

what is the lifespan of RBC in avians?

28 days

what is the lifespan of RBC in amphibians?

800 days (not as active metabolically compared to other species

how many blood groups are in chickens?

28

what RBC shape do camelids have?

Elliptical RBCs; no central pallor

what blood groups do camelids have?

EAA, EAB, EAC, EAD, EAE, EAF

what is important to know about the shape of RBC in deer?

Sickle-cell shaped → pH and temperature differences after drawing blood change them from biconcave to sickle cell shaped

why do healthy RBC have equal distance from one another?

due to negative repulsion forces

what will the distribution of RBC be in an anemic animal?

more sparsely distributed space between RBC and fewer RBC overall

what is the formation of rouleau distribution?

cells lose repelling forces due to decrease in negative surface charge to resemble a stack of fallen coins

what is the significance of rouleau distribution?

seen most with hyperglobulinemia and/or hyperfibrinogenemia

what is the cause of rouleau distribution?

usually inflammation and/or dehydration

what are the species differences with rouleau distribution?

Equine erythrocytes form rouleaux even in healthy horses so this is normal; if you saw it in another species would think inflammation or dehydration

what morphologies would you associate in RBC morphology distribution?

1. rouleau 2. agglutination

what is the formation of RBC agglutination distribution?

antibodies form bridges between RBCs; can be any number of cells clumped, irregular not linear

what is the significance of RBC agglutination distribution?

1. Immune-mediated anemias 2. Interferes with cell counting and sizing methods→ MCV to get hematocrit will be wrongly calculated to be increased because MCV machine sees clumps as large RBC (decrease RBC and increase MCV)

what is the relation of hematocrit and MCV?

should be directly proportional (if one is increased, the other is increased)

what does it mean if there is a "Failure to disperse" result in a Saline Agglutination test?

immune mediated hemolysis (IMH)

what does it mean if there is "dispersion" result in a Saline Agglutination test?

dehydration and inflammation

what size morphologies can you associate in RBC?

1. macrocytosis 2. microcytosis 3. anisocytosis

what is the formation of macrocytosis?

incomplete maturation or skipped cell division; each cell division decreases the size of RBC

what is the significance of macrocytosis?

1. Regenerative anemia→ good bone marrow response to anemia 2. Correlates with increased MCV

what is the significance of macrocytosis in horses?

Best evidence of RBC regeneration in horses (horses do not release immature cells from bone marrow so increased MCV shows that bone marrow is responding to anemia)

what breed of dog do we think of with macrocytosis?

Poodle dyscrasia → characterized by increased red blood cell size (macrocytosis) and other bone marrow abnormalities

what is the formation of microcytosis in RBC?

increased cell divisions of RBC due to a decreased MCV leading to an iron deficiency

what is the significance of microcytosis in RBC?

Iron deficiency due to chronic blood loss → lack of iron means that RBC won't stop mitotic divisions since it does not get signal from erythropoiesis

what variations can occur with microcytosis?

1. Breed variation: akita, shiba 2. Age variation: foals < 6 months

what is the formation of aniocytosis in RBC?

unequal sizes of RBC in blood lead to regenerative anemia

what is the significance of aniocytosis?

Regenerative anemia → due to increased width of RBC → could be due to macrocytes (regenerative) or microcytes (iron deficiency)

what does it mean if RBW reading has increased RBC distribution?

isocytosis

what would you associate with color morphology of RBC?

1. Polychromatophilic Erythrocyte 2. Hypochromic Erythrocyte

what is the formation of polychromatophilic Erythrocyte in RBC?

accelerated erythropoiesis→ done by acceleration from bone marrow

what is the significance of accelerated polychromatophilic Erythrocyte in RBC?

1. Regenerative anemia 2. Purple color caused by RNA of recently released blood cell 3. If cell NMB-stained = reticulocyte

what is the formation of Hypochromic Erythrocyte in RBC?

incomplete or defective hemoglobin synthesis