Week 231 - Anaemia Flashcards
How is anaemia caused in CKD? Want morphology will the resultant anaemia be?
Reduced or absence EPO production leads to reduced stimulation or erythrocyte maturation and therefore anaemia
Normocytic - RBCs will be normal just reduced in number
What is frontal bossing? What anaemia causing condition is it found in and why
Prominent protruding forehead
Found in Thalassaemia due to chronic hypoxic state leading to increase in proportion of erythroblasts, expansion and fatty deposition in bone marrow
What are the differences between a reticulocyte and an erythrocyte?
Reticulocyte is larger, has some organelles (though no nucleus by this stage) and countians roughly 25% of the Hb of a mature erythrocyte
To what molecule does iron bind within a RBC?
Haem
Explain why iron deficiency anaemia results in a microcytic morphology?
RBCs have too few haem molecules in them so the body tries to increase Hb concentration within each cell by stimulating a further cell division hence RBCs are smaller than normal
What do Vitamin B12 and folate do in the body (what is their role)?
They contribute to DNA synthesis, mitosis and metabolism of every cell in the body
What type of anaemia results from Vit B12 or folate deficiency and why?
Megaloblastic macrocytic anaemia
Cells have less DNA, less divisions therefore are larger cells
Thalassaemia is a problem with the production of what element of haemoglobin?
Globin
Sickle Cell Anaemia results from what problem with which element of haemoglobin?
Structure of Globin
Sideroblastic anaemia is caused by a problem with which element of haemoglobin?
The protoporphyrin element of haem
Anaemia of chronic disease leads to a problem with which element of haemoglobin?
Iron element of haem
List the causes of microcytic anaemia
Iron deficiency anaemia
Anaemia of chronic disease
Thalassaemia
Sideroblastic anaemia
List the causes of normocytic anaemia
Acute blood loss Anaemia of chronic disease Pregnancy CKD Marrow infiltration / fibrosis (marrow failure) Haemolytic anaemia Hypothyroidism
List the causes of macrocytic anaemia
Vit B12 or folate deficiency Alcohol excess Liver disease Hypothyroidism Reticulocytosis Drug therapy (e.g. Azathioprine, hydroxycarbimide
What is hepcidin, what does it do and when is it stimulated?
Hepcidin is an iron regulator in the body
It is stimulated by high levels of serum iron and when activated reduces iron degradation in the liver and reduces iron absorption (in duodenum) and reabsorption (in liver)
What is serum ferritin a measure of?
It reflects the amount of stored iron in the body
What differences would you see in blood results when trying to determine whether an anaemia is due to iron deficiency, Thalassaemia, sideroblastic or chronic disease?
Iron deficiency: reduced serum iron and serum ferritin but increased iron binding capacity
The other 3 would demonstrate normal or increased ferritin levels
What 3 correctable factors cause the sickle shape of RBCs in sickle cell anaemia?
Hypoxia
Dehydration
Acidosis
What two overarching fates are sickle cells vulnerable to which ultimately cause most of the signs and symptoms or sickle cell anaemia?
Haemolysis (sickle shape makes them vulnerable to destruction )
Occlusion of blood vessels (leading to hypoxia and ischaemia: pain)
What chronic signs and symptoms of sickle cell anaemia are attributable to haemolysis of RBCs?
Fatigue > reduced oxygen to tissues Pallor > " Impaired growth / dev in children > " Jaundice > destruction of Hb > bilirubin > Gallstones
What acute signs and symptoms of sickle cell anaemia are attributable to haemolysis of RBCs?
Aplastic crisis > Parvovirus B19 > reduced RBCs
What acute signs and symptoms of sickle cell anaemia are attributable to vessel occlusion by RBCs?
Vaso-occlusive crisis (tissue hypoxia)
- bone dactylitis
- lungs (acute chest syndrome)
- stroke
- priapism (pathological erection)
What chronic signs and symptoms of sickle cell anaemia are attributable to vessel occlusion from RBCs?
Splenic dysfunction (increased infections)
What is sequestration in a sickle crisis and what happens?
Sequestration occurs as a consequence of vascular occlusion by sickle cells leaving the spleen. As a result the backed become trapped I the spleen leading to splenomegaly and reduction in blood count > hypovolaemia and potentially shock
What 3 blood results are you likely to see in aplastic anaemia and how will they differ from PRCA (pure red cell aplasia)?
Pancytopenia
Low or absent reticulocyte count
Hypocellular/aplastic bone marrow with increased fat spaces
With PRCA RBCs would be low or absent but WCC and PLTs would be normal
What is pernicious anaemia and how does it occur?
Pernicious anaemia is an autoimmune form of anaemia. Results in Vit B12 malabsorption. Caused by atrophic gastritis which results in absence of gastric parietal cells > no intrinsic factor which is necessary for the binding to and absorption of VitB12 in the terminal ileum
What is EPO and how is it stimulated?
EPO - erythropoietin is a growth factor produced by peritubilar cells in the renal cortex in response to tissue hypoxia. It stimulate bone marrow stem cells to become erythroid precursor cells and ultimately mature erythrocytes (RBCs)
For what reason would oxymetholone be used in the management of Pure Red Cell Aplasia (PRCA)? What type of drug is it?
Oxymetholone is an anabolic steroid. It is used in PRCA to stimulate EPO and therefore RBC production
What is “Roid Rage”?
A potential side effect of anabolic steroid use whereby a person develops aggressive behaviour
Why might an individual with PRCA have pigmented skin?
Due to iron overload which may result from the management
What procedure can be performed to reduce RBC count and serum ferritin if RBC count is over-corrected by treatment for PRCA?
Venesection
How is a Sickle Cell Crisis managed in hospital?
Oxygen Fluid resus Analgesia thromboprophylaxis Transfusion if threshold meant (~70g/L usually)
What 4 medications might you put aSickle cell + Beta Thalassemia patient on?
Hydroxycarbamide (to reduce thrombosis risk)
Folic acid and Ferrous fumerate to improve RBC health
Penicillin as prophylaxis for increased susceptibility to infection
