RBC 2: acquired anaemia Flashcards
(41 cards)
What is anaemia?
- Hb below normal for age and sex
What is included in the normal range for blood Hg?
- Subjects without disease
- Normal distribution
- Mean +/- 2 standard deviations
- Excludes 5% of “normals”
Which factors influence the ‘normal range’?
- Haem varies with age
- Sex: men have higher haem
- Ethnic origin: can effect the mean cell volume
- Time of day sample taken
- Time to analysis
What are the normal references for Hg?
- Male 12-70 (140-180)
- Male >70 (116-156)
- Female 12-70 (120-160)
- Female >70 (108-143)
What are the general features (of anaemia) due to reduced oxygen delivery to tissues?
- Tiredness/pallor
- Breathlessness
- Swelling of ankles
- Dizziness
- Chest pain
- (Depend on age and Hb level)
What are the anaemia features relating to underlying cause?
- Evidence of bleeding
- Menorrhagia
- Dyspepsia, PR bleeding
- Symptoms of malabsorption
- Diarrhoea
- Weight loss
- Jaundice
- Splenomegaly/Lymphadenopathy - may be chronic/acute
What are the anaemia pathophysiologies?
Issues with: Bone marrow, Red cells, Destruction loss

What are red cell indices and what can they show us?
- Automated measure of red cell size and haemoglobin content
- MCV = Mean cell volume (cell size)
MCH = Mean cell haemoglobin
How can anaemia be morphologically described?
- Hypochromic microcytic (small and pale red cells)
- Normochromic normocytic (normal red cells)
- Macrocytic (big flabby red cells)
What does this FBC show?

- Initial tests show hypochromic microcytic
What can haem lab provide for the clinician?
will advise on further appropriate investigations
If hypochromic microcytic what lab tests do we order next?
If Normochromic Normocytic what labs next?
If macrocytic what labs order next?
Serum ferritin
Reticulocyte count [tells us if marrow is functioning correctly - may be sickle cell]
B12/folate, Bone marrow [BM prob may be myelodysplasia]
hypochromic microcytic
What causes low serum ferritin?
What causes normal/increased ferritin?
Low: iron deficiency
Normal/high: Thalassaemia, Secondary Anaemia
How much total body iron?
How is balance maintained?
How is iron recycled?
Where is iron predominantly stored?
4g
Dietary intake balanced by loss
Recycled through breakdown of haem
Predominantly stored in liver
In which form is iron most readily absorbed?
Haem iron is easily absorbed (meat), so more difficult for veggies/vegans
How do we get rid of iron?
Absorbed iron - bound to mucosal ferritin and sloughed off. Transported across the basement membrane by protein ferroportin, then bound to transferrin protein in plasma
Which hormone controls ferroportin? And what does this affect?
Hepcidin
Hepcidin inhibits iron transport by binding to the iron export channel ferroportin
Please explain in brief the iron metabolism
- Iron absorbed in duodenum - Fe2+ > Fe3+
- Transported from enterocytes and macrophages by ferroportin
- Transported in plasma bound to transferrin
- Stored in cells as ferritin
- Hepcidin synthesised in hepatocytes in response to inflammation (also renal failure and ↑iron levels)– blocks ferroportin so reduces intestinal iron absorption and mobilisation from reticuloendothelial cells
Commonest cause of anaemia?
Iron deficiency anaemia (hypochromic microcytic)
hypochromic microcytic
What on history and examination would point to a cause of iron deficiency anaemia?
- History
- Dyspepsia GI bleeding
- Other bleeding, eg menorrhagia
- Diet (NB children and elderly)
- Increased requirement - pregnancy
- Examination
- Signs of iron deficiency
- Abdominal and rectal
hypochromic microcytic
Features on examination pointing towards iron deficiency anaemia?
- Atrophic tongue (although most anaemics complain of this)
- Koilonychia is uncommon to see
hypochromic microcytic
Common causes of iron deficiency anaemia?
- GI blood loss
- Menorrhagia
- Malabsorption
- gastrectomy
- coeliac disease
hypochromic microcytic
How do we manage iron defiency anaemia?
- Correct the deficiency -
- Oral iron usually sufficient
- IV iron if intolerant of oral
- Blood transfusion rarely indicated
- Correct the cause -
- Diet
- Ulcer therapy
- Gynae interventions
- Surgery
Normochromic Normocytic
Causes of increased reticulocyte?
Causes of normal/low reticulocyte?
Increased - Acute blood loss, haemolysis
Normal, low - Secondary anaemia, hypoplasia