Ch. 5 - Microcytic anemia Flashcards
1
Q
What is the MCV needed to have a microcytic anemia?
A
2
Q
what actually causes the microcytosis?
A
an extra division of the erythroblast to maintain the proper Hgb concentration within the RBC
3
Q
What are the four types of microcytic anemia?
A
- iron deficiency anemia2. anemia of chronic disease3. sideroblastic anemia4. thalessemia
4
Q
Decreased levels of iron lead to decreased levels of (blank) which leads to decreased Hgb causing microcytic anemia
A
heme
5
Q
What is the world’s most common nutritional deficiency?
A
iron def.
6
Q
What form is the iron from vegetable derived forms
A
non-heme
7
Q
Where in the GI tract does iron absorption ocurr?
A
duodenum
8
Q
Is heme or non-heme iron more readily absorbed?
A
heme iron
9
Q
(blank) transports iron from the gut lumen to the blood vessel
A
enterocytes
10
Q
enterocytes use what protein to move iron into the blood?
A
ferroportin
11
Q
What is iron bound to in the blood?
A
transferrin
12
Q
what and where is iron bound in the storage form?
A
bound to ferritin in the liver and bone marrow macrophages
13
Q
What does TIBC measure?
A
number of transferrin molecules in the blood?
14
Q
what does % saturation measure? what is normal?
A
number of transferrin molecules bound to iron; 33% is normal
15
Q
What does serum ferritin tell us?
A
reflects the levels of ferritin in the liver macrophages
16
Q
What is the most common causes of iron def. anemia in infants?
A
breast feeding; low iron intake
17
Q
What is the most common causes of iron def. anemia in children?
A
poor diet
18
Q
What is the most common causes of iron def. anemia in adults 20-50?
A
peptic ulcer in males and menorrhagia in females (or pregnancy)
19
Q
What is the most common causes of iron def. anemia in elderly?
A
Western world: colon polyps or carcinomaRest of world: hookworm
20
Q
What two species of hookworm can cause iron def. anemia?
A
Ancylostoma duodonale and Necator americanus
21
Q
How can malabsorption lead to iron def. anemia?
A
If you can’t take the iron in (lets say in Celiac), then you are def.
22
Q
How can a gastrectomy cause iron def. anemia?
A
Gastric acid keeps iron reduced to the Fe2+ state; lower acid levels leads to the less available form of Fe3+
23
Q
What are the clinical features of iron def?
A
Pica, anemia, and koilonychia
24
Q
Describe the changes in RBC morphology in iron def. anemia?
A
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
