Ch. 5 - Microcytic anemia Flashcards Preview

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Flashcards in Ch. 5 - Microcytic anemia Deck (146):
1

What is the MCV needed to have a microcytic anemia?

2

what actually causes the microcytosis?

an extra division of the erythroblast to maintain the proper Hgb concentration within the RBC

3

What are the four types of microcytic anemia?

1. iron deficiency anemia2. anemia of chronic disease3. sideroblastic anemia4. thalessemia

4

Decreased levels of iron lead to decreased levels of (blank) which leads to decreased Hgb causing microcytic anemia

heme

5

What is the world's most common nutritional deficiency?

iron def.

6

What form is the iron from vegetable derived forms

non-heme

7

Where in the GI tract does iron absorption ocurr?

duodenum

8

Is heme or non-heme iron more readily absorbed?

heme iron

9

(blank) transports iron from the gut lumen to the blood vessel

enterocytes

10

enterocytes use what protein to move iron into the blood?

ferroportin

11

What is iron bound to in the blood?

transferrin

12

what and where is iron bound in the storage form?

bound to ferritin in the liver and bone marrow macrophages

13

What does TIBC measure?

number of transferrin molecules in the blood?

14

what does % saturation measure? what is normal?

number of transferrin molecules bound to iron; 33% is normal

15

What does serum ferritin tell us?

reflects the levels of ferritin in the liver macrophages

16

What is the most common causes of iron def. anemia in infants?

breast feeding; low iron intake

17

What is the most common causes of iron def. anemia in children?

poor diet

18

What is the most common causes of iron def. anemia in adults 20-50?

peptic ulcer in males and menorrhagia in females (or pregnancy)

19

What is the most common causes of iron def. anemia in elderly?

Western world: colon polyps or carcinomaRest of world: hookworm

20

What two species of hookworm can cause iron def. anemia?

Ancylostoma duodonale and Necator americanus

21

How can malabsorption lead to iron def. anemia?

If you can't take the iron in (lets say in Celiac), then you are def.

22

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+

23

What are the clinical features of iron def?

Pica, anemia, and koilonychia

24

Describe the changes in RBC morphology in iron def. anemia?

increased RDW, hypochromic, microcytic

25

Describe the four steps of iron def. anemia progression

1. Iron stores depleted2. Serum iron depleted3. Normocytic anemia4. Microcytic, hypochromic anemia

26

What two lab values identify that iron stores are depleted in the first stage of iron def. anemia?

Decreased ferritin and increased TIBC

27

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

28

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

29

All together, what are the lab findings that support iron def. anemia?

decreased ferritinincreased TIBCdecreased serum irondecreased % saturation

30

How do you treat iron def. anemia?

ferrous sulfate

31

What is Plummer-Vinson Syndrome?

iron def. anemia with esophogeal webbing, atrophic glossitis, dysphagia, and BEEFY RED TONGUE

32

What type of anemia is associated with chronic inflammation?

Anemia of chronic disease (ACD)

33

What is the most common type of anemia in hospitalized pts?

ACD

34

Chronic disease leads to production of (blank) from the liver, including hepcidin

acute phase reactants

35

What are the two methods by which hepcidin sequesters iron?

1. limit iron transfer from macrophages to erythroid precursors2. suppress EPO

36

What is the big picture reason why hepcidin hides iron in chronic inflammation?

body thinks its fighting bacteria, bacteria need Fe to grow

37

Why does ACD present as a microcytic anemia?

low iron means low heme means low Hgb means small cells

38

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

39

How do you treat ACD?

treat the underlying cause

40

Sideroblastic anemia is due to a defect in (Fe/protoporphyrin) useage

protoporphyrin synth

41

What is the rate limiting step of protoporphyrin synth?

Succ-CoA to ALA

42

What enzyme catalyzes the rate limiting step of protoporphyrin?

ALAS

43

What vitamin cofactor is necessary for the rate limiting step of protoporphyrin?

B6!!!

44

Where in the cell does Fe bind to protoporphyrin to make heme?

mitochrondria

45

in sideroblastic anemia, in what cellular structure is the iron sequestered?

mitochondria

46

t/F: sideroblastic anemia is only acquired

false; can be congenital from ALAS defect

47

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

48

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

49

What other liver disease has lab values similar to sideroblastic anemia?

hemachromotosis

50

in what cell type is the iron accumulating in sideroblastic anemia?

erythroblasts

51

How many alpha globulin chains are present on csome 16?

4

52

Is alpha-thal caused by gene deletion or mutation?

deletion

53

what happens when one alpha globulin gene is deleted?

pt. is asymptomatic

54

what happens when two alpha globulin genes are deleted?

mild anemia

55

What lab value is associated with a two alpha globulin gene deletion?

increased RBC count

56

Is the cis or trans deletion of two alpha globulin genes worse?

cis; offspring have high chance of severe anemia

57

In what racial pool do we see cis deletions in alpha-thal?

asians

58

in what racial pool do we see trans deletions in alpha-thal?

blacks

59

What form of Hgb is made when three alpha globulin genes are deleted?

HbH

60

What is the globulin make up of HbH?

B4 tetramer

61

What is the globulin make up of HbF?

a2g2

62

what is the globulin makeup of HbA?

a2b2

63

What is the globulin make up of HbA2?

a2d2

64

In three alpha globulin gene deletions, what shows up on electrophoresis?

HbH

65

What is the effect of all four alpha globulin chains being deleted?

FATAL in utero aka hydrops fetalis; formation of g4 tetramers, damages RBCs

66

Is b-thal due to gene mutations or deletions?

mutations; point in the promoter or splice sites

67

in what racial pool do we see b-thal?

african and mediterranean descent

68

How many b globulin genes are on c11?

two

69

What is the name for a gene coding for no b globulin production and one coding for decreased globulin production?

none: B0low: B+

70

What is the genotype of b-thal minor>?

B/B+ (one normal/one low)

71

T/F: b-thal minor is usually asymptomatic

true

72

what is the abnormal lab value associated with b-thal minor?

increased RBC count

73

b-thal minor RBCs are microcytic, hypocrhomic, and (blank) in appearance

targetoid

74

WHat does electrophoresis of b-thal minor blood show?

decreased HbA with increased HbA2 (no beta chains) and HbF increased

75

What is the genotype of b-thal major?

B0/B0

76

when does the anemia present in b-thal major? why?

few months after birth; HbF is protective until the RBCs are degraded

77

What damages the RBCs in b-thal major?

a4 tetramers that precipitate

78

b-thal major causes (intra/extra)vascular hemolysis

extravascular hemolysis

79

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

80

b-thal major pts are at risk of an aplastic crisis after infection with what virus?

parvovirus B19

81

Chronic transfusions to treat b-thal major increases the risk for what disease?

secondary hemochromotosis

82

b-thal major blood smears show microcytic, hypochromic RBCs with target cells and (blank other not normal cells)

NUCLEATED RBCs; holy fucking erythropoeisis, batman!

83

Electrophoresis of b-thal major blood shows what?

HbA2 (no beta chains) and HbF with little to no HbA

84

What is the normal reticulocyte count?

85

How does retic count change in anemia?

falsely increased on the lab report

86

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%

87

(blank) requires an additional correction of (/2) to RETC

polychromasia

88

What color do polychromatic cells appear on the smear?

light cyan blue

89

Where is extramedullary hematopoiesis seen normally in babies and young children?

liver and spleen

90

Generally speaking, where do newborn CBC values lie compared to infants and children?

higher than normal

91

HbF shifts (blank) to the left

oxygen binding curve

92

How long does it take for HbF to be replaced?

6-9 months

93

What is the majority form of Hgb?

HbA

94

In children, higher levels of phosphorus increase synth of 2,3 DPG leading to a (blank) shifted oxygen binding curve

right shifted

95

What is the cutoff for anemia in adult males?

96

what is the cutoff for anemia in adult females?

97

Pregnancy leads to (lower/higher) normal ranges due to increased plasma volume

lower

98

What is the cutoff for anemia in pregnant women?

99

How do you calculate MCV?

(Hct x 1000)/RBC count

100

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

101

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

102

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

103

How do you calculate MCHC?

Hgb/Hct

104

What does a low MCHC imply?

defect in Hgb synth and a microcytic anemia

105

What does a high MCHC imply?

spherocytosis

106

What is a variation in size called?

anisocytosis

107

What does an increased RDW let you know?

can be seen in iron def. anemia; there are new cells being pumped out

108

T/F: mature RBCs lack a mitochondria

true

109

T/F: mature RBCs cannot perform the TCA cycle

true

110

T/F: mature RBCs cannot perform B-ox of fats

true

111

T/F; mature RBCs cannot perform the Pentose Phosphate pathway

FALSE; use it to reduce glutathione!

112

T/F: mature RBCs cannot make ketone bodies

true

113

T/F: mature RBCs cannot perform the Cori cycle

FALSE; that is anaerobic glycolysis and WHAT THEY RELY ON for energy

114

What two cytokines drive ferritin synthesis?

IL1 and TNFa

115

What does a decreased ferritin tell you?

DIAGNOSTIC OF IRON DEFICIENCY

116

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?

117

Where is transferrin synthesized?

in the liver

118

Where is ferritin synthesized?

macrophages of the bone marrow

119

What is the normal serum iron level?

100 ug?dL

120

TIBC correlates with what other lab value?

[Transferrin]

121

What is the normal TIBC?

300 ug/dL

122

What is the normal % saturation?

33%

123

How do you calculate percent saturation?

serum iron / TIBC x 100

124

When ferritin goes down, TIBC (and transferrin therefore) goes (blank)

upTHEY HAVE AN INVERSE RELATIONSHIP

125

Where is dietary iron resorbed? What percent is taken back up?

10% resorbed in duodenum

126

What form of iron cannot be taken up in the gut>?

Fe 3+

127

What vitamin reduces Fe 3 + (ferric iron)?

Vit. C

128

How much iron is stored in the bone marrow macs in men and women?

Men: 1 gwomen: 400mg

129

Besides Hgb and in ferritin, what other molecules in the body use iron?

myoglobin and enzymes (used as cofactor)

130

Achlorhydria (low levels of gastric acid) (inc/dec) availability of dietary iron

decreases

131

What age groups and genders are at highest risk of iron def. anemia?

toddler's 1-2females 12-49 from menstrual loss

132

T/F: NSAIDS may cause iron def. anemia

true, via ulcers

133

What named issue with the small bowel can lead to blood loss based iron def. anemia?

Meckel's diverticulum

134

What impact does prematurity have on Hgb levels?

inadequate and therefore iron def. anemia

135

T/F: paroxysmal nocturnal hemoglobinuria is a type of iron def. anemia

true

136

Iron def. anemia can change platelet counts how?

reactive thrombocytosis

137

Do you treat B-thal?

NOPE

138

What is the common name for Cooley's anemia?

b-thal major

139

What chromosomal abnormality can lead to sideroblastic anemia?

X linked recessive (rare)

140

What percent of hospitalized alcoholics have sideroblastic anemia?

30%

141

Whats another name for Vit. B6?`

pyridoxine

142

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

143

Lead poisoning will denature ribonuclease leading to what finding on peripheral smear?

basophilic stippling

144

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

sideroblastic

145

(blank) is toxic to neurons, causes vascular permeability and edema and demyelination

delta-ALA

146

Do you see ringed sideroblasts in the peripheral smear or the bone marrow?

bone marrow; that's where the iron is being made into Hgb and ultimately stored