Red Cells 2 Flashcards
When revieweing someones Hb blood results and deciding if they are anaemic or not, what other information should you take into account?
The age and sex of the person
Their ethnic origin
The time of day the sample was taken
How is the normal range of hameoglobin defined?
The mean of haemoglobin of subjects without disease +- 2 standard deviations
What is the normal haemoglobin values for a male aged 12-70?
140-180
What is the normal haemoglobin values for a female aged 12-70?
120-160
What are the general clinical features of someone with anaemia?
Tiredness/pallor
Breathlessness & chest pain
Swelling of ankles
Dizziness
What is a red cell indices?
They are diagnostic tests that are part of the FBC and are used to diagnose anaemias
What information does a red cell indices tell you?
Mean Cell Volume (cell size)
Mean Cell Haemoglobin
What are the different morphological descriptions of anaemia?
Hypochromic Microcytic
Normochromic Normocytic
Macrocytic
What is meant by the term hypochromic?
Pale looking RBC’s
What is meant by the term microcytic?
RBC’s smaller than the normal range of MCV
What is meant by the term macrocytic?
RBC’s larger than the normal size range for MCV
What investigations are carried out to confirm a hypochromic microcytic anaemia?
Serum Ferritin
What further tests are carried out to diagnose a normochromic normocytic anaemia?
Reticulocyte count
What further tests are carried out to confirm a diagnosis of macrocytic anaemia?
Check Vitamin B12 & Folate levels
Bone Marrow sample
After identifying a hypochromic microcytic anaemia from red cell indices and a blood film, what would a low serum ferritin result indicate?
The anaemia is caused by an Iron deficiency
After identifying a hypochromic microcytic anaemia from red cell indices and a blood film, what would a normal or increased serum ferritin result indicate?
Thalassaemia OR
Secondary anaemia
Which protein is responsible for binding Heme Iron absorbed from the duodenum?
Ferritin
What happens to Iron which has been absorbed and become bound to ferritin?
1) Sloughed off by shedding of epithelial cells
2) Transported across basement membrane by ferroportin
Once Iron is in the plasma, to which protein does it become bound to?
Transferrin
How is Iron stored in RBC’s?
As Ferritin
What is Hepcidin and where does it come from?
Hepcidin is a protein which regulates the intake of Iron of into the blood stream
Hepcidin is produced by hepatocytes in the Liver
What does hepcidin do?
Hepcidin blocks ferroportin therefore reducing intestinal Iron absorption
In what situations is hepcidin required?
Inflammation
Renal failure
Increased Iron levels
What are the reasons someone might present with an Iron deficiency anaemia?
1 - GI bleeding
2 - Menorrhagia
3 - Diet low in Iron
4 - Being pregnant
What are the clinical features of iron deficiency?
Koilonychia
Atrophic tongue
Angular cheilitis
What are the causes of Iron deficiency anaemia?
GI blood loss (colon cancer, gastric ulcer)
Menorrhagia (heavy period)
Malabsorption (Coeliac disease)
How is Iron deficiency anaemia managed?
1) Correct the deficiency - Oral Iron tablets
2) Correct the cause - diet, ulcer therapy, gynae interventions
After identifying a normochromic normocytic anaemia from red cell indices and a blood film, what would an increased reticulocyte count indicate?
1) Acute blood loss
2) Haemolysis
After identifying a normochromic normocytic anaemia from red cell indices and a blood film, what would a normal or low reticulocyte count indicate?
1) Secondary anaemia
2) Hypolasia
3) Marrow infiltration
What is haemolytic anaemia?
Accelerated red cell destruction (causing reduced Hb)
How does the body compensate for the loss of RBC’s by haemolysis?
Bone marrow increases production of reticulocytes
What are the general causes of haemolytic anaemias?
1) Congenital
2) Acquired
What are the congenital causes of haemolytic anaemia?
1) Hereditary spherocytosis
2) G6PD
3) Haemoglobinopathy
What are the acquired causes of haemolytic anaemia?
1) Auto-immune haemolytic anaemia
2) Artifical valve
3) Severe infections/DIC
What are the two locations where haemolytic anaemia can occur?
1 - Extravascular
2 - Intravascular
Where are the immune causes of haemolytic anaemia most likely to occur?
Extravascular
How is haemolytic anaemia tested for?
Direct antiglobulin test
If the direct anti-globulin test is positive what does that indicate about the haemolytic anaemia?
It is immune mediated
If the direct anti-globulin test is negative what does that indicate about the haemolytic anaemia?
It is non-immune mediated
What are the different types of immune mediated haemolysis?
1) Warm auto-antibody
2) Cold auto-antibody
3) Alloantibody
What tests would you run to identify if a patient is currently haemolysing?
1) FBC
2) Reticulocyte count
3) Blood film
How is haemolytic anaemia managed?
1) Folic acid to support marrow function
2) Immunosuppression if auto-immune
3) Splenectomy
4) Treat sepsis
What is the most common type of secondary anaemias?
Normochromic normocytic
What is the main cause of seoncdary anaemia?
Increased Hepcidin in chronic inflammatory condition
After identifying a macrocytic anaemia from B12/Folate assay , what would a megaloblastic macrocytic anaemia (identified on blood film) indicate was causing the anaemia?
B12 and Folate deficiency
After identifying a macrocytic anaemia from B12/Folate assay , what would a non-megaloblastic macrocytic anaemia (identified on blood film) indicate was causing the anaemia?
Myelodysplasia
Marrow infiltration
What can be the cause of a Vitamin B12 deficiency?
1 - Pernicious anaemia
2 - Gastric disease
What can be the cause of a folate deficiency?
Dietary
Increased folate requirements (haemolysis)
What is the appearance of someone with megaloblastic anaemia?
Lemon yellow tinge
How is Vitamin B12 absorbed?
Vitamin B12 binds to Intrinsic Factor which then attaches to Intrinsic Factor recptors on distal Ileum
From where is intrinsic factor produced?
Gastric parietal cells
What is the cause of pernicious anaemia?
Antibodies against Intrinsic factor
Why is it called ‘pernicious’ anaemia?
The symptoms take 1-2 years to develop
How is megaloblastic anaemia treated?
Correct Vitamin B12 and Folate deficiency
What are some of the other causes of macrocytosis?
Alcohol
Drugs (e.g. methotrexate)
Disordered Liver function
Hypothyroidism