MEH - Anaemias Flashcards by RG Cattermole

What are the micro/normo/macrocytic anaemias?

TAILS - micro - thalassemia, anaemia of chronic disease, iron deficiency, lead poisoning, sideroblastic

ABCD - acute blood loss, bone marrow failure (aplastic or infiltrated), chronic disease, destruction (haemolysis)

FATRBCC - fetus (pregnancy), alcohol (folate deficiency), Thyroid (hypo), reticulocytosis (things causing increased reticulocyte), b12/folate deficiency, cirrhosis (liver disease), Chronic disease

How well did you know this?

Not at all

Perfectly

Can anaemia of chronic disease be micro normo and macro?

Yes

How well did you know this?

Not at all

Perfectly

What is a differential for Iron deficient anaemia as they present quite similarly? What are the similarities

Thalassemia

Both microcytic
Both show target cells
Both show hypochromasia

How well did you know this?

Not at all

Perfectly

How do you test for iron deficient anaemia? What are the problems with the tests?

Serum ferritin - but also is an Acute phase protein so increased in inflammation etc so normal or increased ferritin levels don’t necessarily exclude iron deficiency

CHR - Reticulocyte haemoglobin content - but this is also reduced in thalassemia so can’t be used to differentiate

How well did you know this?

Not at all

Perfectly

What are symptoms/signs of anaemia?

Tiredness
Shortness of breath
Palpitations
Angina

Tachycardia
Pallor
Angula stomatitis
Spooning of nails
Shiny tongue

How well did you know this?

Not at all

Perfectly

What would you see on a blood smear in iron deficient anaemia?

Hypochromasia
Target cells
Anisopoikilocytosis (change in size and shape)
Pencil cells

How well did you know this?

Not at all

Perfectly

What would you expect the blood results to be for iron deficient anaemia (6)?

Low Hb
Low serum ferritin
Low CHR (reticulocyte haemoglobin content)
Increased TIBC (Total iron binding capacity)
Low serum iron
Low % transferrin saturation

How well did you know this?

Not at all

Perfectly

What does TIBC measure?

Bloods capacity to bind iron with transferrin

How well did you know this?

Not at all

Perfectly

What does % transferrin saturation measure?

Measures the amount of iron reversibly bound to transferrin (a protein that binds to iron and transports it into cells e.g. into duodenal cells in absorption and into RBCs to transport iron into them).

Less iron less attaches so less % saturation

How well did you know this?

Not at all

Perfectly

What is a normal MCV?

80-100

How well did you know this?

Not at all

Perfectly

What kinds of things cause haemolytic anaemia (11)?

Sickle cell - due to misshapen and aggregates - break in capillaries

Damaged/prosthetic heart valves - shearing

Myelodysplastic disorders/ leukaemia/lymphoma ?due to autoimmune response?

Pyruvate kinase deficiency

G6PDH deficiency

DIC - due to infection/sepsis

Thalassemia

Hereditary spherocytosis

Autoimmune haemolytic anaemia

Non immune - burns

Osmotic haemolysis - drowning

How well did you know this?

Not at all

Perfectly

What is hereditary spherocytosis?

Only produce spherocytes - get haemolytic anaemia

How well did you know this?

Not at all

Perfectly

What happens in bone marrow failure? How do you diagnose this kind of normocytic anaemia?

Can be aplastic - not producing any RBCs due to multiple myoloma/leukaemia/lymphoma/ drugs/ post viral aplastic

Diagnose with bone marrow biopsy

How well did you know this?

Not at all

Perfectly

What would see on a blood film with Folate/Vit B12 deficiency? Are the distinguishable? When might you see this kind of anaemia?

Megaloblastic - macrocytic
Large cells with arrest of nuclear maturation - large nucleus
Hyper segmented neutrophils

How well did you know this?

Not at all

Perfectly

What is extra medullary haemopoiesis and when might you see it?

Not bone marrow

So liver or spleen taking over role of blood cell production e.g. in Thalassemia

How well did you know this?

Not at all

Perfectly

Why does folate/B12 deficiency cause megaloblastic cells with large nuclei?

As it inhibits DNA synthesis so cells don’t produce enough DNA to divide at the right time and therefore grow too large with large nuclei

How well did you know this?

Not at all

Perfectly

What is the mechanism of anaemia of chronic disease?

Functional lack of iron
Iron not released from macrophages
Reduced RBC made

How well did you know this?

Not at all

Perfectly

How can kidney disease cause anaemia?

Decreased Epo less synthesis

How well did you know this?

Not at all

Perfectly

How does pyruvate kinase deficiency cause anaemia?

RBC can’t complete glycolysis so no ATP is being made –> haemolytic anaemia - normocytic

How well did you know this?

Not at all

Perfectly

What can cause folate deficiency?

Lots of things
Alcohol
Pregnancy
Reduced in diet
Some drugs - e.g. Crohns drugs methotrexate
Coeliac
Urinary loss in liver disease

How well did you know this?

Not at all

Perfectly

What effect does haemolysis of RBC have on Hb in blood?

excess- haemoglobinaemia due to the breakdown of RBC releasing Hb

also increased Bilirubin

How well did you know this?

Not at all

Perfectly

What can increased bilirubin in haemolytic anaemia lead to (2)?

Jaundice

Gallstones

How well did you know this?

Not at all

Perfectly

What is pernicious anaemia? How does it occur?

Type of Vit B12 deficiency that is due to lack of intrinsic factor that is needed for Vit B12 absorption

How well did you know this?

Not at all

Perfectly

Why can’t you treat pernicious anaemia with oral Vit B12? How do you treat it?

Because can’t absorb it

Need to give IM Vit B12

How well did you know this?

Not at all

Perfectly

What are the most common causes of anaemia in pregnancy?

Iron | Folate

What is sideroblastic anaemia?

Bone marrow produces sideroblasts instead of healthy RBCs can't incorporate boy iron into Hb Can be apart of myelodysplastic syndrome

What might you see on a blood test that indicates anaemia of chronic disease? How do you treat it?

Increased ferritin - as storing iron lack of functional iron Increased CRP due to disease? Treat underlying cause

How do you treat anaemia caused by myelodysplastic syndromes?

Usually transfusions | Also chemo and stem cell transplant

Which type of anaemia do you also get neuro symptoms?

Vit B12 get focal demyelination and depression/dementia

Why is folate deficiency dangerous in pregnancy?

Neural tube defects

What do you give as treatment for chronic kidney disease anaemia?

Epo

Why can't someone with an enzyme deficiency e.g. G6PDH have certain drugs?

Due to some drugs e.g. antibiotics having a haemolytic effect

Why might anaemia develop (think broad concepts)

``` RBC synthesis problem Hb synthesis problem Problem with excessive RBC breakdown Cell structure problem Enzyme/metabolism problems ```

What conditions might you see anaemia of chronic disease?

``` Rheumatoid arthritis Systemic Lupus Erythematosus Inflammatory bowel disease (UC/Crohns) TB Bronchiectasis ```

What might you suspect if blood marrow shows a lack of response to erythropoietin (3)?

Either empty bone marrow - e.g. after chemo/toxic insult Infiltrated with cancer e.g. leukaemia so lack of RBC production despite Epo Anaemia of chronic disease

What is the basis of anaemia of chronic disease?

Massive increase in IL-6 and therefore hepcidin stimulated --> lack of functional iron as less absorbed and less released from macrophages for use

What is the relevance of increased CRP in anaemia of chronic disease?

?because inflammation and infection increase CRP and also increase hecepdin

How can you tell if a bone marrow is working overdrive on histology?

Should be 50:50 fat/cells but if way more cells something going on

What 2 things are B12 and folate needed for in DNA synthesis?

Nucelar divisions and nuclear maturation Lags behind cytoplasm so leads to big cells big nucleus open chromatin

Where is iron absorbed in the gut, where is folate absorbed and where is vic B12 absorbed?

Iron - duodenum Vit B12 - ileum Folate - duodenum and jejunum

How is B12 transported in blood? How is vitB12 absorbed in intestine?

Transcobalamin Intrinsic factor

Vit B12 deficiency could result from (4):

1) Poor diet 2) No Intrinsic factor 3) Problem with transcobalamin (can be genetic) 4) Problems with ileum absorption e.g. crohns, ileal resection

What is dietary folate converted into?

Methyl THF

What can severe anaemia from vitb12 or folate deficiency lead to?

Pancytopenia i.e. low platelets and neutrophils too

What is the genetics of sickle cell?

Point mutation valine --> glutamate in position 6 on the beta chain. Sicking disorder heterozygous Severe sickle cell homozygous

What effect does extra medullary haematopoiesis have on spleen and liver?

Hepato and splenomegaly

What does deletion of all four alpha genes lead to in thalassemia?

Hydrops fetalis

What is a red blood cell with 'mouth' and pale called?

Stomatocyte

What is it called if red blood cells are all different shapes and sizes?

Polypoikilocytosis

What is it when RBC are cigar shaped?

Elliptocytes

What is it when RBC are spherical?

Spherocytes

What is it when RBC are spikey?

Acanthocytes

What happens in autoimmune haemolytic anaemia? What are the two types? What is the relevance of temperature?

Temp is when the antibody is most active Warm immune - IgG - 37 degrees Cold immune - IgM - 4 degrees

How might you get tear drop shaped RBCs?

Myelofibrosis - fibrous of bone marrow - little space - RBC have to squeeze out giving the tear drop shape

Why are red blood cells susceptive to oxidative stress? How do they overcome this?

Because they are oxygen carrying to exposed to radicals via this and also subjected to foreign substances in the blood that can cause oxidative stress. Use pentose phosphate pathway to generate NADPH that is used to regenerate glutathione - glutathione donates electrons to reactive oxygen species to prevent them causing damage

What are the body's adaptations to anaemia?

Haemopoeisis - reticulocytes 2,3BPG formation - better use of Hb - favours O2 release at tissues CVS - vasoconstriction and tachycardia, blood redistribution away from skin and to important areas

Why does iron deficiency especially affect epithelial cells?

Because they have a high turn over and require iron | Need it for cytochrome C

Why shouldn't you have gaviscon with oral iron supplements in anaemia?

Reduces absorption of iron | Chelator

Someone with rheumatoid arthritis and anaemia of chronic disease has low Hb but normal iron studies (ferritin etc) and high CRP - explain why

Iron studies are normal because iron still there but has been sequestered in stores - lack of functional iron CRP due to inflammation of rheumatoid - this causes cytokine release - that acts to release hepcidin and this 1) prevents iron absorption from gut 2) Prevents release of iron from stores

Why is serum iron level not a reliable measure of iron deficiency or overload? What is?

As is is subject to diurnal variation and also reduced in ACD Use transferrin saturation for overload - haemochromatosis Use ferritin and CHR in iron deficiency

What is the mode of inheritance of spherocytosis?

Autosomal dominant but autosomal recessive in 25% of cases

How do spherocytes haemolyse? Can they provide enough oxygen for tissues?

Display osmotic fragility so more prone to lysis Can do function of RBC and oxygen so that isn't a problem

What is the main surgical management of severe heredity spherocytosis?

Splenectomy

Why can people with HS get low platelets?

Due to splenomegaly - so it pools platelets

What are some causes of increased lymphocytes (and also increased size - means they're activated)?

``` Virus EBV Leukaemia Lymphoma Infectious mononucleosis ```