Lecture 4 - regeneration, RBC morphology, inclusions Flashcards
never interpret data in raw __ form (uncorrected reticulocyte percent vs. absolute reticulocyte count)
percentage (wallet anology) - absolute numbers matter not percents!
two methods to correct reticulocyte percent
- calculate the absolute reticulocyte count (preferred)
2. calculate the corrected reticulocyte percent
to calculate the absolute reticuloctye count (preferred) what do you need to know
total RBC count from automated analyzer
To calculate the corrected reticulocyte percent what do you need to know
spun PCV %
A dog has a PCV of 30%, a RBC count of 4,500,000 RBC/mcL and an uncorrected reticulocyte of 3%. What is the absolute reticulocyte count
RBC count x uncorrected % = absolute
4500000 x 0.03 = 135,000/mcL
A dog has a PCV of 30%, a RBC count of 4,500,000 RBC/mcL and an uncorrected reticulocyte of 3%. What is the corrected reticulocyte percent?
“normal” PCV for dog = 45% (cats = 37%)
p PCV/”normal” PCV x uncorrected % = corrected %
30%/45% x 3% = 2%
types of hemorrhage
external and internal, acute and chronic
5 common causes of hemorrhaging
- blood sucking parasites
- GI or urogenital lesions
- hemorrage into body cavities/tissues
- trauma
- hemostatic disorders
__ hemorrhaging RBC, Iron, and blood proteins are LOST
External
__ external hemorrhaging can cause so much iron to be lost that RBC production ceases, possibly leading to __
chronic, Fe deficiency nonregenerative anemia
internal hemorrhaging RBC and blood proteins are not lost and __ is conserved
iron
__ may occur from hemoabdomen or hemothorax internal hemorrhaging
autotransfusion
Bleeding GI or UG lesions or blood sucking parasites are examples of __ hemorrhaging
external
trauma is an example of __ hemorrhage
internal or external
bleeding tumors of intra-abdominal or thoracic organs such as a splenic hemangiosarcoma is an example of __ hemorrhaging
internal
some hemostatic disorders cause
internal or external hemorrhaging
acute hemorrhage causes cells and fluid to be lost in equal amounts causing total blood volume in vasculature to __, what do you expect the inital PCV/TS to look like ?
decrease, at first PCV/TS will remain the same bc proportions are not changed. once fluid is replaced the PCV/TS will be low (only takes hours)
3 protective responses to preserve O2 delivery during hemorrhaging
- HR and BP rapidly increase
- Splenic contraction (release RBCs)
- interstitial fluid slowly moves from tissues to BV (dilutes remaining RBC and TP)
__ and __ are classic findings after hemorrhaging
anemia and panhypoproteinemia
interstitial fluid shift starts __ post hemorrhage and continues for __
3 hours, 2-3 days
decreased PCV/TP occurs __ post hemorrhage
12-24 hours
__ can increase PCV acutely and __ can increase PCV slowly
splenic contraction, autotransfusion
normal PCV with low TP
GI protein loss, proteinuria, liver dz
normal PCV with high TP
Increased globulin sythesis, dehydration masked anemia
high PCV with low TP
Protein loss combined with relative or absolute erythrocytosis
high PCV with normal TP
splenic contraction, absolute erythrocytosis, dehydration masked hypoproteinemia
high PCV, high TP
Dehydration
low PCV low TP
Substantial ongoing or recent blood loss, overhydration
low PCV, normal TP
increased RBC destruction, decreased RBC production, chronic hemorrhage
low PCV, high TP
anemia of inflammatory dz, multiple myeloma, other lymphoproliferative dz
it takes __ for BM response to anemia to be seen in the blood
3 to 4 days, before this anemia may look non-regenreative
when does the peak response occur after hemorrhaging
1 week
Response to hemorrhaging in dogs and cats is __, cattle is __, and equids__
prominent, less dramatic (more basophilic stippling though), none visible (reticulocytes are not released from BM in equids)
horses do not release __ or exhibit __ but they do have __ to replace RBCs
reticulocytes, polychromasia, splenic contractions
__ in horses with hemorrhage can mask the anemia
splenic contractions
with RBC regeneration in horses you may see a mild increase in __ and mild increase in __
anisocytosis, MCV
how do you tell if horse with anemia is regenerative
measure PCV/TP every 2 days or do BM examination
5 acquired hemolysis
- immune mediated
- infectious
- fragmentation
- toxic
- osmotic
3 congenital hemolysis (uncommon, will not talk about more)
- glycolytic defects
- membrane defects
- hemoglobinopathies
__ triggers splenic macrophage removal of old RBCs
membrane damage
__ is death of RBCs
eryptosis
most of RBC are recycled in the liver: globin is broken down into __ and heme into __, __, __
globin = AA heme = CO, FE, unconjugated Bilirubin
liver metabolizes bilirubin which mostly
excreted (some is reabsorbed)
__ hemolytic anemia is more common, has rapid clinical course and many causes
acquired
__ is abnormal/pathologic increased rate of RBC destruction
hemolysis (reduces lifespan and causes anemia)
the severity of anemia and clinical signs for hemolysis depends on
how fast the RBCs are destroyed
slow/low grade hemolytic anemia will see
mild anemia but no clinical signs
rapid/severe hemolytic anemia will see
marked anemia and possible death
clinical signs of hemolytic anemia also are influenced by
predominant site RBC are destroyed
__hemolytic anemia, RBC are destroyed by macrophages in spleen and other organs (liver, LNs)
extravascular
__ hemolytic anemia, RBC are destroyed in the blood stream by several different mechanisms
intravascular
__ is abnormally rapid RBC death in NORMAL locations for RBC destruction, it can be acute or chronic and DIC is possible
extravascular
__ has a poor prognosis, abnormally rapid RBC death in ABNORMAL locations and is often __.
intravascular, rapid/acute
RBC death occurs in the __ not in an isolated environment causing circulatin fragments of damaged RBC to increase risk for __ and __
blood stream (intravascular), DIC and Anaphylactic shock
many cases of hemolysis are
mixed, but one usually predominates
key sign of intravascular hemolysis are __ in the plasma and __ in the urine
hemoglobinemia (free Hgb in blood) - causes plasma to be pink/red. hemoglobinuria - brown/red urine
due to rapid/severe intravascular hemolysis the __ become overwhelmed and cannot transport free Hgb to the liver for metabolism and recycling
Hgb transport protein
first sign of intravascular hemolysis is __ followed by __
hemoglobinemia (in plasma), hemoglobinuria (urine), when blood transport proteins are overwhelmed Hgt is passed in urine
Hgb from lysed RBC is metabolized into __ in the liver and is excreted in urine and feces (orange color)
bilirubin
__ is when excess bilirubin is passed in the urine and feces (can happen during hemolysis)
bilirubinuria
if bilirubin excretion and metabolism is backed up due t orapid/severe intravascular RBC death the will see biliruben in ___ and finally in the __
plasma = bilirubinemia, mucocutaneous tissue = icterus
can see clinical icterus with intravascular RBC death as the final location of bilirubin when concentrations are
greater than 2mg/dL
order of biliruben build up
urine (bilirubinuria) - plasma (bilirubinemia) - mucocutaneous tissue (icterus)
order of hgb build up
plasma (hemoglobinemia) - urine (hemoglobinuria)
where can icterus be seen first
back of soft palate (then sclera, vulva, abdomen, ear, gums)
why types of pigmentemia and pigmenturia can be seen with extravascular hemolysis
bilirubinuria, bilirubinemia, mucocutaneous icterus
what types of pigmentemia and pigmenturia can be seen with intravascular hemolysis
bilirubinuria, bilirubinemia, mucocutaneous icterus
hemoglobinemia, hemoglobinuria
what characteristic ddxs differentiates intravascular from extravascular hemolysis!
hemoglobinemia, hemoglobinuria (these are not present in extravascular hemolysis)
accumulation of pigments in urine, plasma, and tissues depends on the __ and __ of RBC destruction
rate and severity
animals with hemolytic dz __ exhibit pigmenturia, pigmentemia, or icterus
DO NOT always
bilirubinuria and bilirubinemia __ distinguish extravascular from intravascular hemolysis
DO NOT (hemoglobinemia/uria DO!)
__ means abnormal RBC shapes, these are possible changes with various causes to hemolysis
poikilocytosis
6 types poikilocytes (abnormal RBC shape)
- acanthocytes (uneven spicules) - do not confuse with echinocytes/crenated cells
- schistocytes (fragments)
- Keratocytes
- spherocytes (no central palar)
- RBC ghosts
- eccentrocytes and pyknocytes
abnormal RBC inclusions seen with various causes of hemolysis
- heinz bodies (oxidative damage)
2. infectious RBC parasites
Acanthocytes should not be confused with normally artifactual __
echinocytes/burr cells/crenated cells (even spicules) - this happens when blood sits in tube too long and ATP is depleted (can be pathologic too, ie envenomation)
__ can be seen with liver dz, fragmentation hemolysis, and tumors
acanthocytes
__ hemolysis occurs secondary to other dz (mechanical, endothelial, thermal injury)
fragmentation
4 mechanical causes for fragmentation hemolysis
- DIC
- Caval syndrom due to heartworms
- glomerulonephritis
- cardiac valve stenosis
3 endothelial injuries that cause fragmentation hemolysis
- hemangiosarcoma
- vasculitis
- splenic or hepatic dz
what kind of thermal injury can cause fragmentation hemolysis
heat stroke and severe burns
common cause in dogs for fragmentation hemolysis is due to secondary dz
DIC
__ are seen in fragmentation hemolysis and DIC
Schistocytes and keratocytes
__ are seen in immune mediated hemolytic anemia (ON EXAM)
Spherocytes (perfectly round with no central palar, microcytic)
__ are coated with immune bodies and macrophages take a bite out of cell causing it to be smaller and Hb to be evenly distributed throughout the cell leaving a dark, no central palar cell
spherocytes (extravascular)
__ cells are seen with intravascular immune lysis (EXAM)
ghost cells (formed in the BV, macrophage undergoes complement mediated lysis of RBC “punches holes”)
__ are why you see hemaglobinemia/uria
ghost cells
__ are seen with oxidative damage to lipid membrane
eccentrocytes (part of cell is clear due to LIPID MEMBRANE oxidation, sticks together pushing hgb out of way)
3 targets for oxidative damage in RBC
- lipid membrane (eccentrocytes)
- heme molecule
- globin portion
__ are seen with oxidative damage to the globin molecule
heinz bodies
__ is a infectious epicellular RBC parasite that can be confused for basophilic stippling (rem cats don’t really get basophilic stippling)
mycoplasma haemofelis
cytauxzoon, babesia, distemper, and mycoplasma are all
RBC inclusions (can cause hemolysis)
macrocytic hypochromic anemia with normal plasma color and regeneration. There are poikilocytes (schistocytes and acanthocytes) on the blood film. what is the cause?
hemorrhage (bc plasma is normal so hemolysis is less likely) and fragmentation hemolysis with possible DIC
thrombocytopenia, prolonged clotting factors, and schistocytes are signs of
DIC