macrocytic anaemia

Question 1

what type of anaemia is suggested with a high MCV?

Answer 1

macrocytic

Question 2

what are two types of macrocytosis?

Answer 2

Megaloblastic

Non megaloblastic

Question 3

what is the most common type of macrocytosis?

Answer 3

megaloblastic

Question 4

what is meant by ‘megaloblastic anaemia?’

Answer 4

A type of macrocytic anaemia where there is a problem in DNA synthesis leading to megaloblasts going into circulation

Question 5

what are two crucial things needed for normal DNA?

Answer 5

Vitamin B12

folate

Question 6

what is a megaloblast?

Answer 6

An immature red blood cell that is large

Question 7

what are causes of megaloblastic macrocytic anaemia?

Answer 7

folate deficiency
vitamin B12 deficiency
drugs that cause a deficiency in b12 or folate

Question 8

what is folate necessary for?

Answer 8

Synthesis of adenosine, guanine and thymidine

Question 9

what drugs can interfere with folate metabolism and absorption?

Answer 9

methotrexate
metformin
antimicrobials( trimethorprim, sulfasalaine)
HIV meds
anticonvulsants
alcohol

Question 10

what are causes of folate deficiency due to an increased demand by the body?

Answer 10

Pregnancy
growth spurts
rapid cell turnover
disseminated cancer
urinary losses

Question 11

what are causes of folate deficiency due to a decreased intake by the body?

Answer 11

Poor diet
elderly
chronic alcohol intake

Question 12

what are causes of folate deficiency due to decreased absorption?

Answer 12

medications
coeliac disease
jejunal resection
tropical sprue

Question 13

where is folate absorbed?

Answer 13

jejunum

Question 14

how long does the body have stores of folate for?

Answer 14

3-5 months

Question 15

what is the reticulocyte count in megaloblastic anaemia?

Answer 15

low because there is a problem with DNA production

Question 16

what is seen on a blood film in megaloblastic anaemia?

Answer 16

anisopsoiilocytosis
macrocytes
ovalocytes
hypersegmented neutrophils

Question 17

In megaloblastic anaemia you get hypersegmented neutrophils on a blood film, what do they look like?

Answer 17

a neutrophil with 5 or more lobes

Question 18

if you see hypersegmented neutrophils on a blood film what is the likely diagnosis?

Answer 18

megablastic anaemia

Question 19

a main cause of megablastic leukaemia is folate deficiency. what are symptoms of folate deficiency?

Answer 19

Sore mouth, ulcers, graying hair, fatigue, weakness, lethargy, pale skin, irritable

Question 20

what is the management for folate deficiency?

Answer 20

• improve diet: broccoli, peas, brown rice

folic acid

Question 21

what drugs can cause macrocytosis?

Answer 21

HIV treatment: reverse transcriptase inhibitors
Anticonvulsants: valproic acid and phenytoin
folate antagonists: methotrexate
metformin

Question 22

how is vitamin B12 metabolised?

Answer 22

combines with methylmalonic acid(MMA) this produces CoA.

Question 23

what happens to the levels of methylmalonic acid in vit B12 deficiency?

Answer 23

MMA levels rise as there is no vit B12 for it to be bound with

Question 24

what is the link between vitamin b12 and homocysteine?

Answer 24

vitamin B12 metabolises homocysteine

Question 25

in vit B12 deficiency what happens to homocysteine levels?

Answer 25

they will rise as there isn't enough B12 to metabolise it

Question 26

what is the recommended UK intake of b12?

Answer 26

1.5mcg

Question 27

where is vitamin B12 absorbed?

Answer 27

terminal ileum

Question 28

what is needed for the absorption of vit B12 in the terminal ileum?

Answer 28

intrinsic factor

Question 29

where is intrinsic factor produced?

Answer 29

parietal cells of the stomach

Question 30

what is responsible in the body for the transport of vit B12?

Answer 30

transcobalamin II and I

Question 31

what are causes of VIT B12 deficiency due to impaired absorption?

Answer 31

pernicious anaemia gastrectomy or ileal resection zollinger ellison syndrome parasite

Question 32

what are causes of vit B12 deficiency due to decreased intake?

Answer 32

Malnutrition | vegan diet

Question 33

what are congenital causes of vit b12 deficiency?

Answer 33

intrinsic factor receptor deficiency | cobalamin mutation gene

Question 34

what are causes of vit b12 deficiency due to the body having increased requirements?

Answer 34

haemolysis HIV pregnancy growth spurts

Question 35

what are examples of medications that cause vit B12 deficiency?

Answer 35

alcohol, metformin, PPI, h2 antagonist

Question 36

what is pernicious anaemia?

Answer 36

A cause of macrocytic anaemia as it causes a deficeincy in B12 an autoimmune disorder due to lack of intrinsic factor leading to a lack of b12 absorption

Question 37

what are clinical consequences of being B12 deficient?

Answer 37

decreased cognition, depression, psychosis, subfertility, cardiomyopathy. glossitis, taste impairment, pancytopenia

Question 38

what is a serious neurological disorder caused by B12 deficiency?

Answer 38

SACDC sub acute combined degeneration of the cord. | neuropathy, myopathy, sensory changes, ataxia, spasticity, gait abnormalities

Question 39

what causes SACDC?

Answer 39

a deficiency in B12 causes increased MMA this remains in the myeloid sheath increased homocysteine cant be converted into methionine so can cause dementia and depression

Question 40

what is non megaloblastic anaemia?

Answer 40

Macrocytic anaemia; large, mature red blood cells not related to defective DNA synthesis

Question 41

what are causes of non megaloblastic anaemia?

Answer 41

chronic alcohol use, hypothyroidism, liver disease, myelodysplastic syndromes, haemolysis