Test 3 review sheet Flashcards
What causes most Megaloblastic anemias?
Defects in DNA synthesis
What is needed for normal nuclear development?
Folate and Vitamin b12
What is iron deficiency associated with?
Microcytic red cells (aka RBCs smaller than usual)
Red cell production in megaloblastic anemia
is asnychronus, nucleus lags behind cytoplasm
When DNA synthesis is affected
Cell division doesn’t occur normally and cells become larger
Methotrexate
a drug that tends to compete with folate absorption
What cells are affected by Folate and B12 Deficiency
Any system of cells that need replacement
Areas of present symtoms for Folate and B12 deficiency
gastrointestinal tract, the skin, and the hematopoietic system
Low folate associated with
Macrocytic anemia
Who needs more folate: Men or Women
Women, especially when pregnant to help baby make blood too
Sources of B12
Meat (the best source) and meat byproducts (mild and eggs)
Cause of Pernicious Anemia
Deficiency of intrinsic factor due to an autoimmune disorder
atrophic gastritis
chronic inflammation and thinning of your stomach lining accompanied by a change in your stomach lining cells to mimic intestinal cells
What does atrophic gastritis affect
Secretion of H+, affecting acidity thus affecting digestion
What does Pernicious Anemia and folate deficiency have in common?
Elevated MVC, Hyper segmented neutrophils, megaloblastic bone marrow findings
What occurs during megaloblastic anemia
MCV is increased, RPI is decreased, thus having macrocytic anemia
What does ineffective erythropoiesis lead to
increased Lactate dehydrogenase increase and increased bilirubin
Pancytopenia
deficiency of all 3 blood cells
Why is pancytopenia found in megaloblastic anemia
Since the cells require DNA synthesis to make cells and replace dead cells
What does pancytopenia lead to?
Decrease in all blood cell counts, but an MCH increase due to RBCs being Macrocytic and normochromic
Ineffective erythropoiesis leads to?
Intracellular death since RBCs never make it to circulation, oval shaped RBCs, and pancytopenia
What is typically found first in megaloblastic anemia?
Hyper segmented neutrophils, are considered a specific thing in megaloblastic anemia
How many lobes depict Hyper segmented neutrophils
6 lobes
erythroid hyperplasia
immature red blood cells (erythroid cells) in the bone marrow are abnormal in size, shape, organization, and/or number
Myeloid cells and Erythroid Precursor ratio
10:1
What does the M:E ratio decrease to? and what does it mean?
1:1; bone marrow is hypercellular and defects in DNA synthesis occurs
What is a test of Pernicious anemia?
Venipuncture test for vitamin B12
What is pernicious anenia associated with
Deficiency of vitamin B12, due to lack of intrinsic factor that’s needed for absorbtion
What is a method for b12 deficiency?
Injection through the muscle to by pass absorption, since intrinsic factor deficiency can’t absorb it all
Schilling test
A test to see if B12 deficiency is due to lack of absorption because of low intrinsic factor or other reasons
What test would be done if a person has megaloblastic anemia
Folate and Vitamin b12 assays to see which one is deficient
Haptocorrin
a salivary protein that binds vitamin B12 found in food
Trypsin
Releases b12 from haptocorrin in the small intestines
Intrinsic factor
Brings the b12 to circulation
Transcobalamin
Most important carrier protein for b12
Result of Bone Marrow Failure (BMF)
decrease in all the blood cells’ elements in the bone marrow, leading to pancytopenia
Aplastic anemia
Rare and fatal syndrome of bone marrow failure, condition that occurs when your body stops producing enough new blood cells
Neutrophil count: Aplastic anemia
less than 0.5 103/dL
Bone marrow: Aplastic anemia
hypocellular with fat, all that’s left are lymphocytes, mast and plasma cells
What test is not needed for testing BMF
platelet count
Age range for aplastic anemia
Any age but mainly in: 10 to 25 years old, as well as in those older than 60 years
Red cells in aplastic anemia
normocytic normochromic, but some macrocytosis
Treatment for those younger than 40: aplastic anemia
hematopoietic stem cell transplant from an HLA-matched donor
Treatment for those older than 40: Aplastic anemia
antithymocyte globulin (ATG) in combination with cyclosporine
ATG: aplastic anemia
decreases the number of activated T cells
cyclosporine: aplastic anemia
inhibits t cell functions thus suppressing the autoimmune suppression of stem cells
Fanconi anemia
autosomal recessive disorder, which means that the gene must be inherited from both parents to express the phenotype
What are acquired aplastic anemia
Myelodysplasia and secondary aplastic anemia
Acquired aplastic anemia
a rare, serious blood disorder, due to failure of the bone marrow failure to produce blood cells
What is a inherited aplastic anemia
Diamond-Blackfan anemia
Inherited aplastic anemia
rare aplastic anemia. so rare that the cause is unknown
What is common of both inherited and acquired aplastic anemia?
normal platelet and neutrophil counts
Diamond-Blackfan anemia
characterized by an isolated PRCA and normal cellularity of myeloid cells
Congenital dyserythropoietic anemia (CDA II)
known as hereditary erythroblastic multinuclearity with positive acidified serum (HEMPAS), most common CDA
Tests for CDA II
Ham test is positive; Sucrose hemolysis test is negative
Myelophthisic anemia
when invading or infiltrating cells replace normal bone marrow cells
chronic renal failure
Leads to low EPO which is the primary cause of anemia
CD34
are decreased with aplastic anemia, identifies HSCs
idiopathic aplastic anemia
aplastic anemia where cause is unknown
Diepoxybutane
DNA cross linking agent, is broken when exposed to Fanconi anemia cells
Resonse to anemia
increase rate of of blood cell production and release
compensated hemolytic disorder
When the marrow response is robust enough to keep up with the rate of red cell destruction, anemia does not develop
immunoglobulin (Ig) antibody
common antibody
What removes red cells at the end of their life
macrophages from the spleen
How long do RBCs live
120 days
protoporphyrin ring is converted to what?
bilirubin which is excreted from body
What happens to globin chains?
Broken to amino acids and are reused for future synthesis
What is released from splenic macrophages?
Bilirubin after degrading protoporphyrin ring
Extravascular hemolysis
liver and spleen macrophages break down RBCs
Intravascular hemolysis
the destruction of red blood cells in the circulation with the release of cell contents into the plasma
hemoglobinemia
hemoglobin in the circulation
When is hemoglobin found in pee
Renal threshold is exceeded and hemoglobin passes through kidneys
urobilinogen
oxidize conjugated bilirubin into various water-soluble compounds
When is free hemoglobin found in plasma
When the amount of free hemoglobin exceeds the capacity of plasma salvage systems (like haptoglobin)
What happens to hemoglobin found in plasma
filtered through kidneys with some iron
Concentration of plasma hemoglobin
greater than 50 mg/dL
When does haptoglobin decrease
free hemoglobin is bound in an attempt to salvage the iron.
chronic extravascular hemolytic process leads to
enlarged spleen (splenomegaly)
Haptoglobin
binds the free hemoglobin and thus decreases in plasma
What is seen with acute hemolysis
elevated reticulocyte count
What test is best for acute hemolysis
reticulocyte count, which requires nothing more than a blood sample
hemolytic anemia
disorder in which red blood cells are destroyed faster than they can be made
What is the result of hemolytic anemia
Erythropoiesis is increased with no change in the production of granulocytes, M:E ratio will therefore be decreased
Hypochromia
red blood cells have less color than normal when examined under a microscope
When is hypochromia present
present when hemoglobin synthesis is abnormal such as in iron deficiency anemia
What do Spherocytes indicate
extravascular hemolysis
Schistocytes
fragmented red cells that result when the red cell membrane is damaged by trauma as can be seen in some intravascular hemolytic anemias
