macrocytic anemias Flashcards

1
Q

what is a macrocytic anemia

A
  • retic are big
  • grouped as megaloblastic vs macrocytic
  • > 100 MCV vs > 115 MCV
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

mechanisms of macrocytic anemia

A
  • abnorm in DNA metabolism (b12 or folate def)
  • shift to immature cells
  • bone marrow disorders- MDS
  • hypothyroidism
  • alcoholism
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how does alcoholism cause macrocytic anemia

A
  • unknown mechanism
  • acetaldehyde has direct effect on RBCs
  • d/t regular ingestion of 80 g of alcohol daily
  • resolution after 2-4 mo
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

types of macrocytic anemias

A
  • reticulocytosis
  • alcoholism
  • liver disease
  • hypothyroidism
  • med effect
  • aplastic anemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

types of megaloblastic anemia

A
  • B12 def

- folic acid def

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

meds that cause macrocytic anemias

A
  • combo antiretroviral therapy for HIV
  • hydroxyurea for sickle cell disease
  • mtx- inhibits dihydrofolate reductase
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

aplastic anemia

A
  • considered a macrocytic anemia
  • more common in Asia
  • biphasic age distribution: 10-25 vs > 60
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

causes of aplastic anemia

A
  • acquired causes
  • autoimmune
  • congenital causes
  • fanconi anemia
  • dyskeratosis congential
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

acquired causes of aplastic anemia

A
  • radiation and chemo, toxins
  • viral infx
  • drugs
  • immune disorders
  • pregnancy
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

clinical presentation of aplastic anemia

A
  • weakness, fatigue
  • cardiopulm compromise
  • progressive anemia
  • mucosal/ skin bleeding, petechiae, menorrhea in women
  • recurrent infx
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is a common cause of death in aplastic anemia

A
  • invasive fungal infections
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

PE findings for aplastic anemia

A
  • generally not helpful
  • pallor or petechiae common
  • purpura
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

lab study findings in aplastic anemia

A
  • pancytopenia, severe anemia
  • normocytic or macrocytic
  • decreased or absent polychromic RBCs
  • reduced cell components, morphologically normal
  • abnormal cells NOT present
  • retic count decreased
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

diagnostic criteria for aplastic anemia

A
  • bone marrow cellularity < 30%
  • absence of severe pancytopenia
  • depression of 2-3 blood elements below normal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

severe aplastic anemia criteria

A
  • bone marrow bx shows < 25%
  • OR
  • bone marrow bx showing< 50% with the following:
  • < 30% of cells are hematopoietic
  • absolute retic count < 40,000
  • absolute neutrophil count < 500
  • platelet count < 20,000
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

very severe aplastic anemia

A
  • criteria for severe met

- ANC < 200

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

essentials for dx of aplastic anemia

A
  • pancytopenia
  • no abnormal hematopoietic cells in circulation or in bone marrow
  • hypocellular bone marrow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

treatment for mild-mod aplastic anemia

A
  • supportive care, treat underlying cause
  • EPO GF likely wont work
  • myeloid GF
  • transfusions
  • abx or antifungals for infx
  • monitor closely
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

treatment for severe aplastic anemia

A
  • allogenic HSCT tx of choice in kids < 20, preferred in adults 20-50
  • immunosuppressive if adults > 50 without HLA match, consider with severe comorbidities
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

prognosis of aplastic anemia

A
  • if untreated 70% 1 year mortality
  • rapidly fatal if severe and untreated
  • most die from fungal infections
  • good survival if HSCT, immunosupressives, improved supportive care
  • 1/3 of pts will relapse
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

fanconi anemia

A
  • most common cause of congenital inherited aplastic anemia
  • autosomal recessive, dx very young d/t severe congenital abnorm
  • progressive bone marrow failure
22
Q

what is a complication of fanconi anemia

A
  • increased malignancy like AML or ALL
23
Q

treatment for fanconi anemia

A
  • supportive modalities
  • androgens
  • hematopoietic GF for transient improvement
  • many become refractory or dev intolerable side effects
  • allogenic HSCT is only option to restore function
24
Q

when would you consider a B12 or folate deficiency based on H&P

A
  • unexplained neuro si/sx
  • older adults
  • alcoholics
  • patients with malnutrition
  • bariatric surgery pts
25
b12 absorption
- comes from animal products: meat, fish, dairy - requires intrinsic factor to be absorbed - B12 + intrinsic factor complex absorbed in terminal ileum
26
how long is B12 sotred for
- 3 years
27
what are the functions of B12
- nucleic acid metabolism - myelin synthesis - critical for DNA synthesis and regulation
28
causes of B12 deficiency
- dietary def is rare - inadequate intrinsic factor - pancreatic insuff - ileal disease - competition for B12 in gut - meds that block absorption: PPIs, metformin - transcobalamin II def- rare
29
si/sx of B12 def
- based on severity of def - glossitis - vague GI disturbances - neurologic sx*
30
neuro sx assoc with B12 def
- peripheral nerves affected first- distal/ peripheral paresthesias - difficulty with balance and proprioception - altered cerebral function
31
PE findings for B12 def
- pale - mildly icteric or sallow - atrophic glossitis - decreased vibration - decreased proprioception - memory disturbances
32
lab findings for B12 def
- macrocytic, MCV 110-140 - HCT as low as 10-15% - pancytopenia if severe - low retic count - low serum b12 - elevated MMA* - elevated total homocystein* - elevated LHD and indirect bili - consider TSH and liver fn
33
essentials of B12 def
- macrocytic anemia - megaloblastic anemia - low serum B12
34
treatment of B12 def
- parenteral replacement if absorption issues: SC or IM - sublingual or PO replacement indef - concurrent folic acid tx: 1 mg PO 1-4 mo - transfusion rarely needed
35
expected response to B12 def tx
- immediate improval - hematologic picture normalizes in 2 mo - hypoK possible in first few days - reticulocytosis days 5-7 - hypersegmented neutrophils disappear after 10-14 d - neuro sx may persist if present for > 6 mo before tx
36
monitoring tx for B12 def
- CBC: 1-2 weeks, 2 mo, periodic | - B12 levels: indefinite monitoring
37
what is pernicious anemia
- autoimmune disease - Ab destroy parietal cells -> atrophic gastritis, bind to/ neutralize intrinsic factor - higher risk for GI/ gastric cancers - must treat B12 def
38
diagnosis of pernicious anemia
- schilling test* - measure gastric acid secretion - Ab to intrinsic factor - anti-parietal cell Ab - serum gastrin elevated - serum pepsinogen low - ratio to pepsinogen I: pepsinogen II low
39
where is folic acid found
- fruits - leafy greens - folate= found in nature - folic acid= synthetic version
40
daily requirements of folic acid
- healthy pts: 50-100 mcg/d | - pregnant/ lactating pts: 600-800 mcg/d
41
how long is folic acid stored in the body
- 2-3 moths
42
where is folic acid absorbed
- through entire GIT | - duodenum or jejunum
43
function of folic acid
- common pathway with B12 - nucleic acid metabolism - critical in DNA synthesis- synth in hematopoietic cells
44
causes of folic acid def
- inadequate daily intake*- most common - reduced absorption- rare - increased requirement i.e. pregnancy - excessive loss - meds - alcohol abuse- lower folic acid stores
45
medications that can cause folic acid def
- mtx - trimethoprim - ethanol - phenytoin
46
si/sx of folic acid def
- based on severity of anemia - glossitis - vague GI disturbances - NO neuro sx
47
PE findings for folic acid def
- depends on severity - pale - mildly icteric or sallow - atrophic glossitis - neuro exam normal*
48
lab findings for folic acid def
- macrocytic anemia- MCV 110-140 - pancytopenia if severe - low retic count - normal B12 - RBC folic acid level low - elevated homocysteine* - normal MMA* - elevated LDH and indirect bili - consider TSH and liver fn
49
essentials of folic acid def dx
- macrocytic anemia - megaloblastic blood smear - reduced folic acid levels in RBCs or serum - normal B12 levels
50
treatment of folic acid def
- folic acid PO daily for 1-4 mo or until hematologic recovery - continue tx if underlying cause cant be fixed - ensure no B12 def
51
expected response to tx of folic acid def
- rapid improvement within 5-7 d - reticulocytosis in 5-7 d - normalization of hematologic abnormalities within 2 mo