Flashcards in Ch. 5 - Microcytic anemia Deck (146):
What is the MCV needed to have a microcytic anemia?
what actually causes the microcytosis?
an extra division of the erythroblast to maintain the proper Hgb concentration within the RBC
What are the four types of microcytic anemia?
1. iron deficiency anemia2. anemia of chronic disease3. sideroblastic anemia4. thalessemia
Decreased levels of iron lead to decreased levels of (blank) which leads to decreased Hgb causing microcytic anemia
What is the world's most common nutritional deficiency?
What form is the iron from vegetable derived forms
Where in the GI tract does iron absorption ocurr?
Is heme or non-heme iron more readily absorbed?
(blank) transports iron from the gut lumen to the blood vessel
enterocytes use what protein to move iron into the blood?
What is iron bound to in the blood?
what and where is iron bound in the storage form?
bound to ferritin in the liver and bone marrow macrophages
What does TIBC measure?
number of transferrin molecules in the blood?
what does % saturation measure? what is normal?
number of transferrin molecules bound to iron; 33% is normal
What does serum ferritin tell us?
reflects the levels of ferritin in the liver macrophages
What is the most common causes of iron def. anemia in infants?
breast feeding; low iron intake
What is the most common causes of iron def. anemia in children?
What is the most common causes of iron def. anemia in adults 20-50?
peptic ulcer in males and menorrhagia in females (or pregnancy)
What is the most common causes of iron def. anemia in elderly?
Western world: colon polyps or carcinomaRest of world: hookworm
What two species of hookworm can cause iron def. anemia?
Ancylostoma duodonale and Necator americanus
How can malabsorption lead to iron def. anemia?
If you can't take the iron in (lets say in Celiac), then you are def.
How can a gastrectomy cause iron def. anemia?
Gastric acid keeps iron reduced to the Fe2+ state; lower acid levels leads to the less available form of Fe3+
What are the clinical features of iron def?
Pica, anemia, and koilonychia
Describe the changes in RBC morphology in iron def. anemia?
increased RDW, hypochromic, microcytic
Describe the four steps of iron def. anemia progression
1. Iron stores depleted2. Serum iron depleted3. Normocytic anemia4. Microcytic, hypochromic anemia
What two lab values identify that iron stores are depleted in the first stage of iron def. anemia?
Decreased ferritin and increased TIBC
What two lab values identify that serum iron is depleted in the second stage of iron def. anemia?
Decreased serum iron and decreased percent saturation
Why does iron anemia first present as normocytic before microcytic?
bone marrow is able to produce normal cells still, just an acceptably lower number of them
All together, what are the lab findings that support iron def. anemia?
decreased ferritinincreased TIBCdecreased serum irondecreased % saturation
How do you treat iron def. anemia?
What is Plummer-Vinson Syndrome?
iron def. anemia with esophogeal webbing, atrophic glossitis, dysphagia, and BEEFY RED TONGUE
What type of anemia is associated with chronic inflammation?
Anemia of chronic disease (ACD)
What is the most common type of anemia in hospitalized pts?
Chronic disease leads to production of (blank) from the liver, including hepcidin
acute phase reactants
What are the two methods by which hepcidin sequesters iron?
1. limit iron transfer from macrophages to erythroid precursors2. suppress EPO
What is the big picture reason why hepcidin hides iron in chronic inflammation?
body thinks its fighting bacteria, bacteria need Fe to grow
Why does ACD present as a microcytic anemia?
low iron means low heme means low Hgb means small cells
What are the following lab values in ACD?1. Ferritin2. TIBC3. Serum Iron4. % saturation5. FEP
1. increased ferritin2. decreased TIBC3. decreased serum iron4. decreased % sat5. increased FEP
How do you treat ACD?
treat the underlying cause
Sideroblastic anemia is due to a defect in (Fe/protoporphyrin) useage
What is the rate limiting step of protoporphyrin synth?
Succ-CoA to ALA
What enzyme catalyzes the rate limiting step of protoporphyrin?
What vitamin cofactor is necessary for the rate limiting step of protoporphyrin?
Where in the cell does Fe bind to protoporphyrin to make heme?
in sideroblastic anemia, in what cellular structure is the iron sequestered?
t/F: sideroblastic anemia is only acquired
false; can be congenital from ALAS defect
What are the three major causes of acquired sideroblastic anemia?
1. Alcoholism; mito poison2. Lead poisoning; inhibits ALAD and ferrochelatase3. Vit. B6 def.; seen as a SE from isoniazid Tx for TB
What are the following lab values in sideroblastic anemia?1. ferritin2. TIBC3. serum iron4. % saturation
1. increased ferritin2. decreased TIBC3. increased serum iron4. increased % satruationIRON OVERLOADED STATE
What other liver disease has lab values similar to sideroblastic anemia?
in what cell type is the iron accumulating in sideroblastic anemia?
How many alpha globulin chains are present on csome 16?
Is alpha-thal caused by gene deletion or mutation?
what happens when one alpha globulin gene is deleted?
pt. is asymptomatic
what happens when two alpha globulin genes are deleted?
What lab value is associated with a two alpha globulin gene deletion?
increased RBC count
Is the cis or trans deletion of two alpha globulin genes worse?
cis; offspring have high chance of severe anemia
In what racial pool do we see cis deletions in alpha-thal?
in what racial pool do we see trans deletions in alpha-thal?
What form of Hgb is made when three alpha globulin genes are deleted?
What is the globulin make up of HbH?
What is the globulin make up of HbF?
what is the globulin makeup of HbA?
What is the globulin make up of HbA2?
In three alpha globulin gene deletions, what shows up on electrophoresis?
What is the effect of all four alpha globulin chains being deleted?
FATAL in utero aka hydrops fetalis; formation of g4 tetramers, damages RBCs
Is b-thal due to gene mutations or deletions?
mutations; point in the promoter or splice sites
in what racial pool do we see b-thal?
african and mediterranean descent
How many b globulin genes are on c11?
What is the name for a gene coding for no b globulin production and one coding for decreased globulin production?
none: B0low: B+
What is the genotype of b-thal minor>?
B/B+ (one normal/one low)
T/F: b-thal minor is usually asymptomatic
what is the abnormal lab value associated with b-thal minor?
increased RBC count
b-thal minor RBCs are microcytic, hypocrhomic, and (blank) in appearance
WHat does electrophoresis of b-thal minor blood show?
decreased HbA with increased HbA2 (no beta chains) and HbF increased
What is the genotype of b-thal major?
when does the anemia present in b-thal major? why?
few months after birth; HbF is protective until the RBCs are degraded
What damages the RBCs in b-thal major?
a4 tetramers that precipitate
b-thal major causes (intra/extra)vascular hemolysis
Massive erythroid hyperplasia in b-thal major can be seen by hematopoesis in what bones and (splemogealy/HSM)? What does this look like on XRAY?
skull and face bones; crewcut appearance and chipmunk facies, and HSM
b-thal major pts are at risk of an aplastic crisis after infection with what virus?
Chronic transfusions to treat b-thal major increases the risk for what disease?
b-thal major blood smears show microcytic, hypochromic RBCs with target cells and (blank other not normal cells)
NUCLEATED RBCs; holy fucking erythropoeisis, batman!
Electrophoresis of b-thal major blood shows what?
HbA2 (no beta chains) and HbF with little to no HbA
What is the normal reticulocyte count?
How does retic count change in anemia?
falsely increased on the lab report
How do you correct the retic count in anemic pts>?
(Actual Hct/45) x retic countExample: Hct 20%RETC: 15 %(20/45) x 15 = 6.6%
(blank) requires an additional correction of (/2) to RETC
What color do polychromatic cells appear on the smear?
light cyan blue
Where is extramedullary hematopoiesis seen normally in babies and young children?
liver and spleen
Generally speaking, where do newborn CBC values lie compared to infants and children?
higher than normal
HbF shifts (blank) to the left
oxygen binding curve
How long does it take for HbF to be replaced?
What is the majority form of Hgb?
In children, higher levels of phosphorus increase synth of 2,3 DPG leading to a (blank) shifted oxygen binding curve
What is the cutoff for anemia in adult males?
what is the cutoff for anemia in adult females?
Pregnancy leads to (lower/higher) normal ranges due to increased plasma volume
What is the cutoff for anemia in pregnant women?
How do you calculate MCV?
(Hct x 1000)/RBC count
If your corrected retic count is greater than 3% in normocytic anemia, what does it mean?
means that the bone marrow response is EFFECTIVE in handling the anemia via erythroid hyperplasia
If your corrected retic count is less than 3% in normocytic anemia, what does it mean?
means that the bone marrow response is INEFFECTIVE in hanlding the anemia via erythroid hyperplasia
T/F: A corrected retic count greater than 3% means that the anemia is not caused by RBC defects
FALSE; caused by INTRINSIC or EXTRINSIC RBC defects
How do you calculate MCHC?
What does a low MCHC imply?
defect in Hgb synth and a microcytic anemia
What does a high MCHC imply?
What is a variation in size called?
What does an increased RDW let you know?
can be seen in iron def. anemia; there are new cells being pumped out
T/F: mature RBCs lack a mitochondria
T/F: mature RBCs cannot perform the TCA cycle
T/F: mature RBCs cannot perform B-ox of fats
T/F; mature RBCs cannot perform the Pentose Phosphate pathway
FALSE; use it to reduce glutathione!
T/F: mature RBCs cannot make ketone bodies
T/F: mature RBCs cannot perform the Cori cycle
FALSE; that is anaerobic glycolysis and WHAT THEY RELY ON for energy
What two cytokines drive ferritin synthesis?
IL1 and TNFa
What does a decreased ferritin tell you?
DIAGNOSTIC OF IRON DEFICIENCY
What does an icreased ferritin tell you?
ACD or iron overload, you know....since it is used for storage...got too much grain the silo, eh?
Where is transferrin synthesized?
in the liver
Where is ferritin synthesized?
macrophages of the bone marrow
What is the normal serum iron level?
TIBC correlates with what other lab value?
What is the normal TIBC?
What is the normal % saturation?
How do you calculate percent saturation?
serum iron / TIBC x 100
When ferritin goes down, TIBC (and transferrin therefore) goes (blank)
upTHEY HAVE AN INVERSE RELATIONSHIP
Where is dietary iron resorbed? What percent is taken back up?
10% resorbed in duodenum
What form of iron cannot be taken up in the gut>?
What vitamin reduces Fe 3 + (ferric iron)?
How much iron is stored in the bone marrow macs in men and women?
Men: 1 gwomen: 400mg
Besides Hgb and in ferritin, what other molecules in the body use iron?
myoglobin and enzymes (used as cofactor)
Achlorhydria (low levels of gastric acid) (inc/dec) availability of dietary iron
What age groups and genders are at highest risk of iron def. anemia?
toddler's 1-2females 12-49 from menstrual loss
T/F: NSAIDS may cause iron def. anemia
true, via ulcers
What named issue with the small bowel can lead to blood loss based iron def. anemia?
What impact does prematurity have on Hgb levels?
inadequate and therefore iron def. anemia
T/F: paroxysmal nocturnal hemoglobinuria is a type of iron def. anemia
Iron def. anemia can change platelet counts how?
Do you treat B-thal?
What is the common name for Cooley's anemia?
What chromosomal abnormality can lead to sideroblastic anemia?
X linked recessive (rare)
What percent of hospitalized alcoholics have sideroblastic anemia?
Whats another name for Vit. B6?`
What three enzymes does lead poisoning denature?
1. ferrochelatase: binds Fe to protoporphyrin in the mito2. ALAD; increase in ALA3. ribonuclease: prevents breakdown of ribosomes
Lead poisoning will denature ribonuclease leading to what finding on peripheral smear?
What type of anemia is this?Abdominal colicEncephalopathy (due to increased δ–ALA)growth retardation (maybe not in Tommy boy’s case though)Peripheral neuropathyNephrotoxicityBurton’s line
(blank) is toxic to neurons, causes vascular permeability and edema and demyelination