Exam 2 Highlights Flashcards
What are the compensatory mechanisms activated by reduced tissue oxygenation?
- Hb-O2 curve shifts left in the lungs, shifts right in the tissues
- increased temp, 2,3-DPG, CO2; decreased pH favors offloading in tissues
- increased CO
- increased peripheral vasoconstriction to focus blood supply to vital organs
- BM expansion
Which compensatory mechanism for tissue hypoxia occurs slowly?
- BM expansion; all of the others occur quickly
How does increased 2,3-DPG facilitate oxygen delivery to tissues?
produces a morphologic change to hgb favoring offloading at tissues
In what species is an increased 2,3-DPG effective in compensating for tissue hypoxia?
dogs and humans
In what species is increased 2,3-DPG not effective in compensating for tissue hypoxia?
cats and horses
Describe the pattern of blood loss anemia
- hypoproteinemia
- neutrophilia
- stress leukogram
- regenerative unless chronic
- thrombocytopenia
- reticulocytosis
- rebound thrombocytosis is possible
What can chronic blood loss anemia present as?
iron deficiency anemia (microcytic hypochromic nonregenerative)
Describe the pattern of EV IMHA
- reticulocytosis and regeneration
- spherocytes
- hyperbilirubinemia
- bilirubinuria
- icterus
Describe the pattern of IV IMHA
- regeneration and reticulocytosis
- ghost cells
- hemoglobinemia
- hemoglobinuria
- unconjugated bilirubin
Describe the pattern of oxidative damage/HB anemia/maple leaf toxicity
- heinz bodies
- eccentrocytes
What are heinz bodies?
sulfhydryl groups are crosslinked and makes a nose like projection or a clearing in the cell
- denatured hgb
What are eccentrocytes?
clearing on one side of the cell because hgb aggregates toward one side and the membrane folds on itself
What are some causes of oxidative damage?
- onions and garlic
- propofol
- phenothiazines
- acetaminophen
- vitamin K1
- zinc
- copper
- DKA
- lymphoma
- hyperthyroidism in cats
What two metabolic products typically protect cells from oxidative injury?
NADPH and glutathione from anaerobic glycolysis
Describe the pattern of fragmentary anemia
- schistocytes
- keratocytes
- acanthocytes
What causes fragmentary anemia?
- DIC
-IDA - vasculitis
- endocarditis
- hemangiosarcoma
- caval syndrome (HW)
- thrombosed catheter
Describe the pattern of microangiopathic hemolytic anemia
- spherocytes
- fragmentary changes
Describe the pattern seen with mycoplasma
- acute hemolytic disorder
- rod or coccoid strung in a line or as purple bubbles in red cells
What is the primary agent of mycoplasma infections in the US
mycoplasma haemofelis
What is the reservoir host of mycoplasma haemofelis?
bobcats
When can mycoplasma haemocanis cause disease?
immunocompromised or splenectomized patients
Describe the pattern of babesiosis
- protozoa
- gibsoni look like purple dots that are smaller than anaplasma and HJ bodies
- canis can appear as large purple fluke things inside RBCs
Describe the pattern seen with anaplasmosis
- tick borne pathogen
- two purple dots inside RBCS (look similar to HJ bodies)
Describe the pattern of leptospirosis
- bacterial infection
- hemolysin and phospholipases cause lysis of RBCs
Describe the pattern of clostridium hemolyticum
can produce hemolysin and phospholipases that cause hemolytic anemia
Describe the pattern seen with PK deficiency
- decreased red cell life span
- die of liver disease or anemia because of hemosiderosis
myelofibrosis - reticulocytosis
What breeds are commonly associated with PK deficiency?
- Basenji
- Abyssinian
- Somali
What breeds are associated with PFK deficiency?
- English spring spaniel
- cockers
- whippets
Describe the pattern of PFK deficiency
- decreased enzymes –> susceptible to alkaline lysis –> dog pants and RBCs lyse
- decreased 2,3-DPG
Describe the pattern of myelophthistic anemia
- neoplastic cells, fibrosis, fungal granulomas replace hematopoietic BM
- causes pancytopenia
- cannot be reversed
Describe the pattern of estrogen toxicity
- causes aplastic anemia - nonregenerative anemia with hypoproliferative BM
- pancytopenia
Describe the pattern of chronic renal failure
- decreased/lack of production of EPO
- nonregenerative anemia
- REP cells that produce EPO are transformed into myelofibroblasts due to chronic inflammation or stressful events
- uremic toxins and inflammatory cytokines contribute to decreased EPO
- hepcidin increases due to decreased kidney clearance
- reduction of RBC life span
- blood loss b/c of uremic toxins causing intestinal ulceration
Describe the pattern of Ehrlichia canis infection
- IMHA secondary autoimmune cause –> can be nonregenerative
- can cause aplastic anemia
Describe the pattern associated with FeLV infection
- megaloblastic anemia
- nonregenerative anemia with hypoproliferative erythroid lineage
- cells are too large and have a nucleus (megalocytic cells do not have a nucleus)
- macrocytic normochromic (no polychromasia)
- megaloblastic rubricytes and metarubricytes
Describe the pattern of IDA
- microcytic hypochromic nonregenerative anemia
- iron stores are depleted
- hyperproliferative BM
- cytoplasmic maturational defect –> failure to form hgb
What causes IDA?
- nutritional (mom’s milk or parasitism)
- chronic blood loss (serum iron and serum ferritin are decreased)
IDA becomes nonregenerative only in what two scenarios?
- chronic blood loss is prolonged and severe
- diet is deficient
Describe the pattern of anemia of inflammatory disease
- nonregenerative anemia with hypoproliferative BM
- PCV does not go below 20%
- most common anemia
- can develop in 7-10 days
- dysregulation of iron homeostasis –> iron trapped in macs and not absorbed from GIT
- normal/decreased serum iron, increased ferritin
- inflammatory cytokines inhibit EPO production
- fever shortens life span of RBCs
- increased hemosiderin in macs
- erythroid hypoplasia
- EPO levels are normal to decreased
How do you treat anemia of inflammatory disease?
- tx underlying problems
- iron or EPO administration is of little to no help
Describe the pattern of lead toxicity
- mild normocytic normochromic nonregenerative anemia
- basophilic stippling –> pyrimidine-5’-nucleotidase
- nRBC due to stromal damage - inappropriate numbers relative to degree of polychromasia/reticulocyte response
- cytoplasmic maturational defect
- leads interferes with synthesis of hgb and degradation of ribosomes
What is the mechanism of spherocyte production?
IMHA –> Coomb’s positive
- extravascular splenic macrophage plucking of the red cell membrane when macs are triggered to remove Ag on cell surface
- mediated by IgG
What can cause IMHA and spherocytosis?
- inherited disorders
- transfusion reactions
- fragmentation anemias
What is the mechanism of ghost cell production?
- IMHA
- IV lysis mediated by IgM –> bind and activate complement –> MAC –> hole punched into red cell –> red cell lysis –> ghost cells
What is the mechanism of heinz body production?
- oxidation of IC hgb sulfhydryl groups of red cells
- causes nose like projections or clearings
- caused by disruption of PPP in glycolytic pathway that normally produces NADPH and glutathione
What is the mechanism of eccentrocyte production?
- oxidation of membrane sulfhydryl groups of red cells
- causes sulfhydryl groups to be pushed to one side of the cell –> off sided placement of hgb
What is the mechanism of stomatocyte production?
- abnormal phospholipid composition –> increased Na and water influx
- increased permeability of membrane
- macrocytic hypochromic
- have a narrow elongated CP
What breeds are known to have stomatocytes?
- schauzers
- pomeranians
- drentse patrijshound
- alaskan malamute (chondroplasia)
What is the mechanism of target cell/leptocyte/codocyte production?
- lloks like a bullseye
- increased surface to volume ratio
- greater resistance to osmotic lysis
- balanced increased amounts of cholesterol and phospholipid in the red cell membrane
indicates liver disease
What is the mechanism of acanthocyte production?
- irregularly spiculated red cells
- unbalanced increased in cholesterol and phospholipid composition of the red cell membrane
- indicates liver disease
- classified as fragmentation injury –> hemangiosarcoma, DIC, IDA
What is the mechanism of schistocyte production?
- fragmented red cells
- mechanical injury
- often only in low numbers
- DIC, vasculitis, turbulent blood flow, fragile cells, IDA
What is the mechanism of torocyte production?
- red cells with large CP and a thick hgb rim
- usually artifact
What is the mechanism of ovalocyte/elliptocyte production?
- oval to elongated red cells
- indicative of liver disease (hepatic lipidosis), myelofibrosis (BM scarring and red cells have to squeeze out), inherited
What are inherited causes of ovalocytes/elliptocytes?
- red cell membrane and cytoskeletal protein deficiency
- red cell membrane band 4.1 deficiency
- mutation in beta-spectrin
What is the mechanism of dacrocyte production?
- looks like a teardrop
- ovalocytes and dacrocytes are diagnostic for myelofibrosis
- red cells have to squeeze and wiggle out of scarred BM
Start with question 6 on exam 2 review
IV v. EV hemolysis
