Erythrocytes Part 1 Flashcards
1
Q
what is the function of erythrocytes?
A
transport oxygen to tissues
2
Q
in what species do red blood cells have less concavity?
A
cats
cattle
horses
3
Q
what is most energy of red blood cells provided by?
A
anaerobic glycolysis
red blood cells lack mitochondria
4
Q
what does the Na/K ATPase in red blood cells do?
A
maintain gradient between cytoplasm and extracellular fluid
5
Q
what are the components of hemoglobin?
A
heme
iron
globin (protein)
6
Q
where is heme synthesized?
A
mitochondria
7
Q
what is assessed in red blood cells?
A
number/mass
indices: parameters
morphology
8
Q
where is globin synthesized?
A
ribosomes
9
Q
how is hematocrit calculated by hematology analyzers?
A
based on volume and number of red blood cells
10
Q
what are some abnormalities of red blood cell number/volume?
A
anemia
polycythemia or erythrocytosis
11
Q
what does regenerative anemia usually indicate?
A
increased destruction or loss of red blood cells
12
Q
what does nonregenerative anemia result from?
A
decreased hematopoiesis/erythropoiesis
13
Q
what are the red blood cell indices measurements of?
A
red blood cell size and hemoglobin content
14
Q
what is the mean cell volume?
A
average volume of individual erythrocytes
15
Q
what is macrocytic/macrocytosis?
A
increased mean cellular volume
16
Q
what are some causes of macrocytosis?
A
regenerative anemia: most common
FeLV infected cats
toy/miniature poodles
folate or cobalamin deficiency
drugs that interfere with DNA synthesis
myelodysplasia or dyserythropoiesis
17
Q
when might microcytosis be seen?
A
some breeds have it normally
iron deficiency/chronic blood loss: most common
portosystemic shunting
copper deficiency
lead poisoning
18
Q
what is red cell distribution width a measurement of?
A
variation in size of red blood cells
19
Q
what is the mean cell hemoglobin concentration (MCHC)?
A
average concentration of hemoglobin in red blood cells
20
Q
what is hypochromasia?
A
decreased mean cell hemoglobin concentration
21
Q
why might you see hypochromasia?
A
regenerative anemias: immature red blood cells have less hemoglobin
iron deficiency
22
Q
when might you see hyperchromasia?
A
artifacts:
hemolysis
heinz bodies
lipemia
red blood cell agglutination
23
Q
what is CHCM?
A
cell hemoglobin concentration mean
24
Q
how does cell hemoglobin concentration mean measure?
A
laser backscatter to measure hemoglobin in intact red blood cells
less susceptible to hemolysis artifact
25
what are red blood cells evaluated for for the morphologic assessment?
size
color and central pallor
abnormal shapes
inclusions or infectious agents
26
what can cause an increase in polychromasia or reticulocytes?
accelerated release of immature red blood cells from bone marrow in anemia
27
what is polychromasia?
basophilic red blood cells seen in blood film
28
what is the basophilia in polychromasia due to?
low hemoglobin content and higher RNA content
29
what is basophilic stippling?
basophilic, dot-like inclusions in red blood cells
30
what is basophilic stippling caused by?
aggregated ribosomes
31
what are poikilocytes?
abnormally-shaped red blood cells
32
what with poikilocytes may provide a clue about the causes of anemia/disease?
type of poikilocytes
33
what are the most common type of poikilocytosis?
echinocytes (or crenated red blood cells)
34
what are echinocytes characterized by?
uniformly-sized and spaced out bumps or spikes
35
what is the most common significance of echinocytes?
drying artifact: usually no clinical significance
36
when might echinocytosis occur that have clinical significance?
uremia
snake envenomation
glomerulonephritis
red blood cell dehydration
neoplasia
electrolyte losses in horses
commonly found in normal pigs
37
what are acanthocytes?
similar to echinocytes, but with irregularly-sized or spaced projections
38
what is the theoretical mechanism to acanthocytes?
increased cholesterol content in red blood cell membranes
39
when might acanthocytes occur?
hypercholesterolemia
liver disease
erythrocyte fragmentation/turbulence injury
young goats, deer, or cattle
40
what are schistocytes/schizocytes?
small, irregularly-shaped red blood cell fragments
41
what are some causes of schistocytes?
hemangiosarcoma
disseminated intravascular coagulation
glomerulonephritis
iron deficiency
heartworm disease/caval syndrome
liver disease in cats
vasculitis
42
what are keratocytes?
acanthocyte-like cell with two horns or spikes
43
when do eccentrocytes occur?
red blood cell membrane oxidizes and fuses together, excluding cytoplasm from that area
44
when are eccentrocytes found?
oxidative cell injury
45
what are the red blood cell indices?
red blood cell volume
red blood cell hemoglobin content
red blood cell hemoglobin concentration
red blood cell size variation
46
what do spherocytes appear as?
small, dense red blood cells
no central pallor
47
who are spherocytes typically reported in?
only dogs: lack of central pallor in normal red blood cells of other species
48
what do spherocytes most commonly result from?
removal of part of erythrocyte cell membrane without loss of cytoplasm
49
what can cause spherocytes?
immune-mediated anemia
fragmentation injury
oxidation
bee stings or snake envenomation
50
how can immune-mediated anemia cause spherocytes?
macrophages remove part of red blood cell typically because antibody is bound to cell
51
what are red blood cell ghosts?
empty membranes from lysed red blood cells
52
what types of hemolysis can cause red blood cell ghosts?
intravenous
in vitro
53
what are leptocytes?
abnormally thin red blood cells
54
what do codocytes look like?
excess membrane forms a bump in middle of cell
55
what can cause codocytes?
immature red blood cells
increased membrane cholesterol
splenectomy
iron deficiency
56
what do howell-jolly bodies look like?
small, dark-staining, usually round inclusions
57
what are howell-jolly bodies?
remnant of extruded nucleus
58
what are heinz bodies?
red blood cell inclusions formed when hemoglobin is oxidized and precipitates
59
is it normal for cats to have low number of heinz bodies?
yes
1-5% of red blood cells
60
when might increased heinz bodies be seen in cats?
oxidant ingestion
propofol anesthesia
"metabolic" diseases
61
when are increased nucleated red blood cells often seen?
conjunction with polychromasia as part of regenerative response
62
increased nucleated red blood cells without polychromasia may be termed _________________________________
innappropriate metarubricytosis
not part of regenerative response
63
what is anemia?
decreased red blood cell mass
or hemoglobin
64
patients with ___________ anemia typically display milder clinical signs than a patient with ___________ anemia due to ______________________
chronic
acute
compensation/adaptation
65
how can a patient compensate for anemia?
increased levels of erythrocyte 2,3-diphosphoglycerate
increased cardiac output
redistribution of blood flow
increased oxygen extraction in tissues
66
how can anemias be classified?
red blood cell parameters
regenerative vs nonregenerative
classification based on cause if known
67
how can you assess regeneration?
increased reticulocyte count
blood film
red blood cell indices
erythroid hyperplasia in bone marrow
68
what are the two terms for immature anucleate red blood cells?
reticulocytes
polychromatophils
69
how long does the regenerative response to anemia typically take?
3-5 days to begin
7-10 days for full response
70
do horses release significant numbers of reticulocytes in regeneration?
no
71
what do ruminants often exhibit in regeneration?
basophilic stipling
72
what are the basic causes of regenerative anemia?
hemorrhage
increased red blood cell destruction
73
what percentage of blood can animals lose without going into hypovolemic shock?
25-30%
74
loss of ___________ blood volume leads to hypovolemic shock
30-40%
75
loss of ___________ blood volume leads to death
>50%
76
in what species can the spleen contract to increase hematocrit?
dogs
horses
cats
77
what happens with fluid after acute blood loss?
fluid enters vascular space to restore lost circulatory volume
extra fluid dilutes the remaining blood
anemia may take 12-24 hours to appear
78
what patterns of PCV and TS can be seen with acute blood loss?
low PCV and low TS unless very acute
may have low TS but normal PCV due to splenic contraction
internal blood loss may cause low PCV with normal protein
79
how can you tell hemolysis is intravascular with the blood?
hemolyzed plasma typically
artifactual increase in MCHC
maybe RBC ghosts
80
what is commonly seen with urine with intravascular hemolysis?
hemoglobinuria
bilirubinuria
81
how can you tell hemolysis is extravascular?
clear plasma
no hemoglobinuria
hyperbilirubinemia, bilirubinuria common
82
what is immune mediated hemolytic anemia caused by?
binding of antibodies to red blood cells, leading to increased destruction
83
is immune mediated hemolytic anemia usually intravascular or extravascular?
extravascular, can be intravascular
84
what are the causes of immune mediated hemolytic anemia?
autoimmune hemolytic anemia
red blood cell infections/parasites
incompatible blood transfusion
neonatal isoerythrolysis
drug interactions
idiopathic
85
what is another finding with immune mediated hemolytic anemia with the liver?
hypoxia-induced hepatocellular necrosis
86
what does agglutination indicate?
antibody on red blood cell surface
87
what are some reported causes of drug-induced immune mediated hemolytic anemia?
cephalosporins
penicillin
levamisole
sulfonamides
88
which blood groups are the most immunogenic in equines?
Aa
Qa
89
what is the most immunogenic blood group in dogs?
DEA 1
90
how long is the half life of transfused blood in type A cats that receive type B?
2 days
91
what blood type are queens with neonatal isoerythrolysis in their kittens?
queens type B
kittens type A or AB
92
how can hemotropic mycoplasmas be diagnosed?
microscopic examination of blood
PCR analysis of blood
93
how can hemotropic mycoplasmas be treated?
tetracycline/doxycycline
94
which Mycoplasma is more pathogenic for cats?
M. hemofelis
95
what is feline hemotropic mycoplasmosis like?
varies from asymptomatic to marked anemia
96
how is Mycoplasma haemosuis spread?
in utero
blood transfer
97
who does Anaplasma marginale impact?
cattle
98
how is anaplasmosis transmitted?
ticks
biting flies
99
what does Babesia canis look like on a blood smear?
relatively large, teardrop shaped piroplasms
100
where is Babesia canis most common?
south and southeast US
101
what does Babesia gibsoni look like on a blood smear?
small piroplasms
102
what does cytauxzoonosis cause in cats?
hemolytic anemia
usually rapid death
103
where do schizonts of cytauxzoonosis in cats grow?
macrophages
104
what is the pathogenicity of Hemoproteus sp like in birds?
low: more than 50% of erythrocytes parasitized without signs of disease
105
what are the vectors of Hemoproteus sp?
insects
106
who do Plasmodium sp infect?
birds
107
who do Haemogregarines infect?
reptiles
amphibians
fish
108
what can Leucocytozoon sp cause in birds?
anorexia
dehydration
depression
hemolytic anemia
hemoglobinuria
109
how can FeLV cause anemia?
induction of IMHA
immunosuppression and secondary infections
myelodysplasia
bone marrow neoplasia/myelophthisis
110
what do some serovars of Leptospirosis induce?
acute hemolysis: calves, piglets, lambs
111
can Fe oxidation be reversed?
yes
112
what is the toxic dosage of acetaminophen in cats?
10 mg/kg
113
what does hypophosphatemia lead to?
low ATP levels in red blood cells and decreased membrane integrity
114
what is PK deficiency?
deficiency of pyruvate kinase
deficient ATP production
115
why is PK deficiency a problem?
increased extravascular hemolysis
