Nutritional anaemias

Question 1

what is anaemia?

Answer 1

Anaemia is a condition in which the number of red blood cells (and consequently their oxygen-carrying capacity) is insufficient to meet the body’s physiological needs. / also low levels of haemoglobin

Question 2

what are the ingredients for making RBCs

Answer 2

Vitamin B12 folic acid and iron (also cytokines and healthy bone marrow niche)

Question 3

What are the 3 causes for anaemia

Answer 3

Failure of production of haemoglobin
Ineffective erythropoiesis (rbc production)
Decreased survival (blood loss, haemolysis, reticulocytosis)

Question 4

What is reticulocytopenia?

Answer 4

a reticulocyte is an immature red blood cell, reticulocytopenia is a condition where there is an abnormal level of reticulocytes in the body

Question 5

What does failure of production of haemoglobin/rbcs mean

Answer 5

it means there might not be enough ingredients resulting in hypo proliferation (not enough rbcs produced)
or it could be due to reticulocytopenia (not enough baby rbcs in the body)

Question 6

what does ineffective erythropoiesis mean

Answer 6

decreased output of rbcs basically ineffective rbc production

Question 7

how do we investigate anaemia

Answer 7

based on whether blood test results show rbcs are microcytic (smaller than normal) or macrocytic (bigger than normal)

Question 8

why are macrocytic rbcs bad

Answer 8

they dont have enough nutrients

Question 9

what causes rbcs to be macro and microcytic

Answer 9

microcytic- Iron deficiency
macrocytic- B12, folate deficiency

Question 10

what role does iron have in blood

Answer 10

O2 transport

Question 11

why do daily requirement for women after 51 years become the same as men

Answer 11

menopause they no longer have periods and no longer need more iron to make up for blood loss.
(pregnant women have the highest iron requirement)

Question 12

where does most of our iron go and how

Answer 12

most of it goes to bone marrow to be carried by blood via transferrin a transport protein (some goes to muscles and liver)

Question 13

where is iron stored

Answer 13

in the liver and can be transferred back out via transferrin

Question 14

how many states of iron are there in the body and what form are they mostly found as in the body

Answer 14

Fe+3 (ferric state) Fe+2 (ferrous state), most of it is found as Hb (haemoglobin)

Question 15

what are the transport and storage proteins of iron

Answer 15

ferritin
haemosiderin
found in bone marrow spleen and liver

Question 16

how is iron absorption regulated

Answer 16

GI mucosal cells and hepcidin

Question 17

How does hepcidin regulate iron absorption?

Answer 17

Causes ferroportin internalization and degradation decreasing the iron transfer into the blood plasma from the duodenum.

Question 18

what are the duodenum and the jejunum

Answer 18

Duodenum- First part of the small intestine
Jejunum- middle part of the small intestine

Question 19

how does the duodenum and jejunum regulate iron absorption

Answer 19

They contain ferroportin receptors on cells which transfer iron into the plasma where the iron binds to transferrin and is taken wherever needed

Question 20

what cells have ferroportin receptors

Answer 20

enterocyte cells (a cell of the intestinal lining)
found in the Duodenum and Jejunum

Question 21

What affects the amount of iron the body absorbs

Answer 21

Type of iron ingested (Heme, Ferrous, non heme)
GI acidity
Iron storage levels
Bone marrow activity

Question 22

how does hepcidin regulate iron absorption

Answer 22

it gets rid of ferroportin receptors available (by degradation and internalisation) which means iron can no longer be transferred to the plasma and cant bind to transferrin.

Question 23

how is hepcidin regulated

Answer 23

via iron conc and rbcs production demand for iron

Question 24

what happens to excess iron

Answer 24

stored as ferritin (a storage protein)

Question 25

What happens to the levels of transferrin and ferritin in iron deficiency?

Answer 25

Transferrin- increased Ferritin- decreased

Question 26

How can we test for iron deficiency?

Answer 26

Iron binding studies

Question 27

what does low ferritin levels show and how can it be artificially increased

Answer 27

low ferritin levels mean low iron levels (i.e iron deficient) Ferritin is part of the immune system so if you're unwell it can be raised

Question 28

what are causes of iron deficiency

Answer 28

Blood loss (mensturation, undiagnosed GI tract blood loss, parasites) Poor diet (can also be because of malabsorption or ^inc physiological needs)

Question 29

how is iron deficiency investigated

Answer 29

full blood count: checks Hb conc, mean cell volume, mean cell haemoglobin and reticulocyte count (baby rbc count) blood film BMAT (bone marrow biopsy)- very outdated

Question 30

How does Iron deficient anaemia (IDA) present under a microscope?

Answer 30

Microcytic (smaller than WBC) Hypochromic (pale)

Question 31

what are the symptoms of IDA (iron deficiency anaemia)

Answer 31

Symptoms: fatigue, lethargy, dizziness Signs: pallor of mucous membrane, bounding pulse, systolic flow murmurs, smooth tongue, koilonychias (spoon nail, the centre of the nail is depressed and starts looking like a spoon)

Question 32

Why are B12 & folate grouped together?

Answer 32

Both have similar clinical findings and are normally found together but can be isolated from one another in diagnosis

Question 33

what happens with B12 and/or folate deficiency

Answer 33

macrocytic anaemia They have low Hb and high MCV (mean corpuscular volume, meaning bigger cell with more volume), as well as normal MCHC (mean corpuscular haemoglobin concentration).

Question 34

How do the previous symptoms (macrocytic anaemia blood results) cause anaemia?

Answer 34

Because the cells are bigger and have more volume this means they can hold more Hb in ONE cell, this gives the illusion of a healthy cell in a patient if you're only looking at MCHC (Hb conc in a cell) since the cell is larger and has a higher capacity for Hb, however overall there is low Hb since there aren't enough cells in the body to keep up with Hb demand meaning theres less cells overall resulting in less Hb overall causing anaemia.

Question 35

macrocytic anaemia has 2 descriptions

Answer 35

Megaloblastic- Vitamin B12 or folate deficiency, or drug related Non-megaloblastic- every other cause

Question 36

B12 and folate sources

Answer 36

fish, meat, dairy vegetables (oil), liver B12 folate

Question 37

What are some differences between Megaloblastic and non-megaloblastic anaemias?

Answer 37

Megaloblastic- Hyper segmented neutrophil (too many nucleus nodes in a neutrophil, normally has 3-4 where you can see up to 7 in a B12/Folate deficient patient), oval RBCs Non-megaloblastic- has many macrocytic rbcs present but there is no uniformity to rbc size, theres just a bunch of different rbcs with no pattern in size.

Question 38

what is folate used for

Answer 38

A, T, G synthesis

Question 39

what are causes of folate deficiency

Answer 39

increased demand- breast feeding, growth spurts, cancer, rapid cell turnover, heart failure decreased intake- diet, elderly, alcohol decreased absorption- medicine, coeliac, jejunal resection, tropical sprue

Question 40

what is vitamin b12 essential for

Answer 40

methylation in DNA and cell metabolism necessary for homeostasis of MMA and homocysteine

Question 41

what are some lab studies they carry out for iron

Answer 41

Fe serum- hugely variable in the day Ferritin Transferrin (inversely proportional to Fe stores) Transferrin saturation- amount of transferrin that is bound to iron Total Iron binding capacity- measurement of the capacity of transferrin to bind to iron (indirectly measures transferrin) Difficult to carry out and is unreliable, ferritin is the most reliable measure of iron levels of a patient

Question 42

How is ferritin measurement sometimes unreliable?

Answer 42

It is also part of the immune system meaning if there is an infection or any activity of the immune system ferritin levels can be artificially boosted by such causes

Question 43

Why is transferrin inversely proportional to Fe stores

Answer 43

because the less fe available the more the body wants to transfer from the stores so they increase transferrin production to try make up for the lack of iron in the body. basically supply and demand if you think about it there was more supply so less demand now theres less supply so more demand

Question 44

How is B12 absorbed

Answer 44

In the terminal Ileum (last section of the small intestine) via intrinsic factor (a glycoprotein made in stomach parietal cells found in the stomach same cell make acid)

Question 45

what is pernicious anaemia

Answer 45

an autoimmune disease where antibodies attack either intrinsic factor or parietal cells destroying them so there is lack of B12 absorption resulting in anaemia no amount of B12 supplementation will rectify this as it wont be absorbed, you need B12 injections straight into the blood to treat this.

Question 46

What are some causes of B12 deficiency?

Answer 46

Impaired absorption- pernicious, gastrectomy/ ileal resection, parasites, zollinger-ellison syndrome decreased intake- malnutrition, vegan diet Congenital causes- IF receptor deficiency, folate mutation CG1 gene inc req- Haemolysis, HIV, pregnancy, growth spurts Medication- Alcohol, NO, metformin, PPI/H2 antagonists

Question 47

What is the difference between Iron deficient anaemia and B12 and/or folate anaemia?

Answer 47

Iron- Microcytic (smaller rbc) Folate &/or B12- Macrocytic (enlarged rbc)

Question 48

Why are B12 & folate grouped together?

Answer 48

Both have similar clinical findings and are normally found together but can be isolated from one another in diagnosis

Question 49

What are the haematological consequences of B12 deficiency?

Answer 49

MCV- Normal or raised Hb- Normal or low Reticulocyte count- Low LDH- Raised Blood film- Macrocytes, ovalocytes, hyper segmented neutrophils BMAT- Giant metamyelocytes, hypercellular, megaloblastic (Large immature WBCs, very unusual to need this test) MMA- Increased

Question 50

What are some clinical consequences of B12?

Answer 50

Brain: low cognition, depression, psychosis Neurology- sensory changes, ataxia (disorder of balance and speech), spasticity (abnormal muscle stiffness), myelopathy (compressed spine) Infertility cardiomyopathy Tongue: taste impairment, glossitis Blood: Pancytopenia (deficiency of rbc wbc and platelets)