Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Haematology > Megaloblastic Anemia > Flashcards

Megaloblastic Anemia Flashcards

1
Q

What are the causes of megaloblastic anemia❓

A

Vitamin B12 deficiency

Vitamin B9 deficiency

Combined deficiency of B12 and B9

Drugs

Inherited metabolic diseases

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

How would you define megaloblastic anemia❓

A

A disorder characterized by:

  • Defective nuclear maturation
  • Due to impaired DNA synthesis
  • Usually as a result of B12/B9 deficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What % of macrocytic anaemias is caused by B9 and or B12 deficiencies❓

A

30-50%

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

What MCV of RBC would pass for a macrocytic cell❓

A

MCV >95-100

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

What is the RDA of B12 for adults❓

What is the RDA of B12 for pregnant/lactating women ❓

A

A: 2 microgram/day

P: >2 microgram/day

L: 2.5-3 microgram/day

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

Average diet contains ____ B12/day

What is the plasma level of B12❓

A

5-30 microgram/day

200-900 ng/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Amount of B12 stored up in the body is ❓

As❓

Where❓

How long would it take to deplete the store❓

A

2-5 mg

Adenosylcobalamin (coenzyme B12)

Liver

3-6 years

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the plasma level of folate❓

_____ serum folate levels will qualify for folate deficiency

A

6-21 microgram/L

<4 microgram/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The RDA of folate is❓

Diet contains how much folate per day❓

A

3 microgram/kg for >10yrs old

100-500 microgram/day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the RBC level of folate❓

_____ RBC folate levels will qualify for folate deficiency

A

160-640 microgram/L

<140 microgram/L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Amount of B9 stored up in the body is ❓

As❓

Where❓

A

5-20 mg

N5-methyl folate

Liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Megaloblastic haematopoiesis presents with:

Anemia
+/-Leukopaenia
+/-Thrombocytopenia

Why❓

A

DNA synthesis is impaired and will affect all cell lines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the causes of VitB12 deficiency❓

A

⬇️intake:
Strict vegetarianism

🚫absorption:
Gastrectomy
Caustic injury
Ileal resection/disease
Pancreatic insufficiency
Imerslund-Grasbeck dx (familial selective B12 absorption defect
Drugs (colchicin, neomycin, omeprazol, ethanol)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Causes of folate deficiency❓

A

⬇️intake:
Alcoholism
Tropical/non-tropical sprue
Intestinal resection

⬆️demands:
Pregnancy 
Chronic hemolytic dx 
Myeloproliferative dx 
Dermatitis 
Hyperthyroidism 
Drugs:
Oral contraceptives 
Anticonvulsants
Triamtrene 
Cholestyramine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the causes of combined deficiency of B9 and B12❓

A

Tropical sprue

Gluten enteropathy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What could cause acute megaloblastic anemia❓

A

NO anesthesia
Dialysis
Drugs like trimethoprim
Parenteral feeding

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

Megaloblastic anemia can be due to what drugs❓

A

DHFR inhibitors eg methotrexate
Trimethoprim

Purine antagonists eg
Azathioprin

Pyrimidine antagonists eg
ARA-C

Alkylators eg
Cyclophosphamide

Zidovudine

18
Q

Which inherited metabolic disorders could lead to megaloblastic anemia❓

A

Orotic aciduria

Lesch-Nyhan Syndrome

Transcobalamin II deficiency

Homocysteinuria

19
Q

The clinical features of folate and cobalamin are alike in 2 presentations and differ in one.

Briefly discuss

A

•Folate deficiency:
✅Anemia
✅Atrophic glossitis
🚫neurologic changes

•Cobalamin deficiency:
✅Anemia
✅Atrophic glossitis
✅neurologic changes*

*cobalamin helps in myelination of nerves in the CNS, hence ⬇️cobalamin presents with neurologic changes

20
Q

Do you know any other organs/tissues affected by megaloblastic anemia❓

A 
Skin
GI
Genital system mucosal epithelium 
Congenital abnormalities (Neural tube defects)
Neurologic changes 
Hyperhomocysteinemia
21
Q

What are the clinical findings in B12 deficiency❓

A 
Neurologic changes:
Paresthesias 
Loss of position sense 
Ataxia 
⬇️tendon reflexes 
Muscles weakness 
Loss of vibration sense (dorsal c)
Spasticity 
Babinsky sign (lateral c) 
Romberg sign (dorsal c) 
Memory loss, dementia, confusion 
Vitiligo 
Hyperpigmentation 
Greying of hair 
Weight loss 
Fever 
Diarrhea 
Constipation 
Splenomegaly
22
Q

Giving folate to a B12 deficient pt may correct/prevent anemia but make neurologic deficits worse

True or false

A

True

23
Q

To conclude a case of megaloblastic anemia, RBC indices should show❓

A

⬆️MCV
⬆️MCH
⬆️RDW

24
Q

A peripheral smear of megaloblastic RBC would show❓

A

Macroovalocytosis

Anisocytosis, poikilocytosis

Bazophilic stippling

Howell-Jolly bodies, Cabot ring

Nucleated red cells

Neutrophil hypersegmentation

25
Q

Neutrophil hypersegmentation is an early sign of megaloblastic hematopoiesis

True or false

A

True

26
Q

What are the bone marrow findings you’ll expect to see in megaloblastic anemia❓

A

Erythroid hyperplasia

Giant erythroblasts
(megaloblasts)

Giant megakaryocytes

Nuclear cytoplasmic asynchronism

⬆️mytosis

⬆️iron stores

27
Q

Compare and contrast the special lab tests you’ll order for to differentiate a B12 deficiency from a B9 deficiency

A

B12 deficiency:
⬇️serum B12
⬆️methylmalonic acid excretion
Hyperhomocysteinemia

B9 deficiency:
⬇️serum folate
⬇️RBC folate
Hyperhomocysteinemia

28
Q

They should NEVER be an administration of B9 to a B12 deficient patient

True or false

A

TRUE!

29
Q

How would you treat a B12 deficient patient

A

Cobalamin replacement:

1000 microgram/day IM for 2weeks
1000 microgram/week until Hb returns to normal

30
Q

Megaloblastic changes should be lost in B12 deficient patient following cobalamin replacement in how many days❓

A

1-3days

31
Q

Reticulocytosis should be reversed in B12 deficient patient following cobalamin replacement in how many days❓

A

5-8 days

32
Q

Hypersegmentation should be lost in B12 deficient patient following replacement therapy in how many days❓

A

1-2 weeks

33
Q

Hb should normalize in a B12 deficient patient following replacement therapy in how many days❓

A

5-6 weeks

34
Q

MCV should normalize in a B12 deficient patient following replacement therapy in how many days❓

A

10 weeks

35
Q

Cobalamin replacement could result in hypokalemia

True or false

A

True

36
Q

How would you treat a B9 deficient patient

A

Folic acid replacement:
S: 1mg/day for 2-3weeks
C: 0.25 - 0.50 mg/day

Treat underlying dx

37
Q

What is pernicious anemia?

It is also known as?

A

Deficiency of intrinsic factor, w:

Megaloblastic anemia
Atrophic glossitis
Neurologic changes

Addison - Biermer dx

38
Q

What are the types of pernicious anemia❓

A

Adult: 60years

Juvenile: 10-20years

Congenital: <2years

39
Q

Adult type pernicious anemia is due to❓

A

Atrophic gastritis:
⬇️gastric secretion
🚫chief and parietal cells
✅Intestinal metaplasia

40
Q

Congenital type pernicious anemia is due to❓

A

Selective IF deficiency

41
Q

Selective IF deficiency is an autosomal recessive disease

True or false

A

True

42
Q

How would you treat pernicious anemia?

A

Life long cobalamin replacement

Haematology (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions