Iron Deficient Anaemia Flashcards
what is the physiological response to anaemia?
reticulocytosis
what is Hb criteria for anaemia in males?
HB<130G/L
what is Hb criteria for anaemia in females?
HB<120G/L
what is HCT criteria for anaemia in males?
HCT 0.38 – 0.52
what is HCT criteria for anaemia in females?
HCT 0.37-0.47
what are the pathophysiological classifications of anaemia?
Decreased production
Increased loss or destruction
What are the morphological classifications of anaemia?
microcytic anaemia
Macrocytic anaemia
what are the two types of anaemia related to decreased production?
Hypoproliferative
Maturation abnormality - cytoplasmic defects, nuclear defects
what is the mechanism hypoproliferative anaemia?
reduced amount of erythropoiesis
what is the mechanism of anaemia caused by cytoplasmic defects?
impaired haemoglobinisation
what is the mechanism of anaemia caused by nuclear defects?
impaired cell division
what is the mechanism of microcytic anaemia?
problems with haemoglobinisation
what is the mechanism of macrocytic anaemia?
consider problems with maturation (cell division)
what are the main symptoms of anaemia?
fatigue, dyspnoea, faintness, palpitations, headaches, tinnitus, anorexia, angina
what are the main signs of anaemia?
pallor, hyperdynamic circulation (tachycardia, flow murmurs, cardiac enlargement, retinal haemorrhage, HF)
what investigations are used in anaemia diagnosis?
History/Examination FBC Reticulocyte count Blood film features Haematinics Bone marrow biopsy specialised tests (HB, A2, HLPC) Measure Haemoglobin, Haematocrit
what types of anaemia does reduced reticulocyte count indicate?
Micro/Macrocytic
Normocytic
What types of anaemia does increased reticulocyte count indicate?
Haemolysis
Bleeding
how can haemolysis be differentiated to bleeding?
look for red cell breakdown products
Haemolysis - raised unconjugated serum bilirubin, increased urinary urobilinogen
what are the causes of microcytic anaemia?
haem deficiency
Problems with porphyrin synthesis
Globin deficiency
what are the causes of haem deficiency in microcytic anaemia?
Lack of iron for erythropoiesis - iron deficiency, anaemia of Chronic Disease
what are the causes of porphyrin synthesis problems in microcytic anaemia?
o Lead poisoning
o Pyridoxine responsive anaemias
what are the causes of globin deficiency in microcytic anemia?
Thalassaemia (trait, intermedia, major)
where is Hb synthesised?
cytoplasm
what is needed to make Hb?
o Globins
o Haem - Porphyrin ring + Iron (Fe 2+)
what do cells look like in microcytic anaemia?
Small
Hypochromic
what are the causes of iron deficiency anaemia?
Blood loss: GI bleeding (peptic ulcer, diverticulitis), Menorrhagia, hookworm (developing countries)
Poor Diet
Malabsorption
what are the causes of anaemia of chronic disease?
infection, colloagen vascular disease, rheumatoid arthritis, malignancy, renal failure, chronic inflammatory disease (crohns), TB, endocarditis.
survival.
what are the causes of sideroblastic anaemia?
Inherited or – Acquired
2* to myelodysplasia, alcohol, lead or isoniazid poisoning, idiopathic, malignancy, anti- TB drugs, malabsorption
what are the investigations for iron deficiency anaemia?
– Hb ↓, ↓MCV – RBC microcytic, hypocgromic, anisocytosis, poikilocytosis. -Serum ferritin ↓ -Serum Iron ↓ – TIBC ↑
what are the investigations for Anaemia of chronic disease?
– ↓serum iron levels
– ↓ serum iron binding capacity
– ↑or normal serum ferritin.
what are the histological features for sideroblastic anaemia?
refractory anaemia
hypochromic cells in the peripheral blood
ring sideroblasts in bone marrow.(erythrocytes with granules of iron in their cytoplasm)
what is the management of iron deficiency anaemia?
Treat underlying cause.
– Oral iron – ferrous sulphate
what is the management of anaemia of chronic disease?
– Treat underlying cause
– If due to renal failure recombinant erythropoietin
what is the management of sideroblastic anaemia?
Withdraw causative agents
– some response to pyridoxine (Vit B6)
– Maybe transfusion dependent and iron overload is a problem
what is the disease progression of iron dependent
- Exhaustion of iron stores
- Iron deficient erythropoiesis
- Microcytic Anaemia –
- Epithelial changes- systemic effects
what are the types of causes of iron deficiency anaemia?
diet
malabsorption
blood loss
what diets can lead to iron deficiency anaema?
o RELATIVE deficiency - especially women of child bearing age and children
o ABSOLUTE deficiency - vegetarian diets
what are the causes of malabsorption leading to iron deficiency anaemia?
o Coeliac disease
o achlorhydria
what are common causes of blood loss that can lead to iron deficient anaemia?
o Menorrhagia
o Gastrointestinal, Tumours, Ulcers, NSAIDs, Occult blood loss
o Haematuria
what are the clinical features characteristic of iron deficient anaemia?
- Koilonychia
- Atrophic glossitis
- Angular cheilosis
- Post-crocid webs
what are the cell volume features of iron deficient anaemia?
↓MCV, ↓MCH, ↓MCHC
what is functional iron?
haemoglobin
what is transported iron?
o Serum iron
o Transferrin
o Transferrin saturation
what is storage iron?
Serum ferritin
what is the functional iron in iron deficient anaemia?
o Haemoglobin (reduced)
what is transported iron levels in iron deficient anaemia?
o Serum iron (↓)
o Transferrin (receptors ↑)
o Transferrin saturation (reduced)
what is storage iron levels in iron deficient anaemia?
o Serum ferritin (↓)
how is iron deficient anaemia diagnosed?
combination of anaemia (decreased functional iron) and reduced storage iron (low serum ferritin)
how is iron deficient anaemia managed?
- treat the cause
- oral iron – e.g. ferrous sulphate 200mg/8h PO
- Continue until Hb is normal or for 3 months
what are the side effects of ferrous sulphate?
nausea, abdominal discomfort, diarrhoea or constipation, black stools
what are the causes of Anaemia of Chronic Disease?
- Chronic infection (TB)
- Vasculitis
- Rheumatoid
- Malignancy
- Renal failure
what is the pathophysiology of anaemia of chronic disease?
- Poor use of iron in erythropoiesis
- Cytokine-induced shortening of RBC survival
- ↓ production of and response to erythropoietin
- Inflammatory Macrophage iron block
what is the process of inflammatory macrophage iron block?
o Increased transcription of ferritin mRNA stimulated by inflammatory cytokines so ferritin synthesis increased
o Increased plasma hepcidin blocks ferroportin-mediated release of iron
o Results in impaired iron supply to marrow erythroblasts and eventually hypochromic red cells
what is the ferritin level in anaemia of chronic disease?
normal or raised
what anaemia is present in anaemia of chronic disease?
Mild normocytic anaemia
what is the management of anaemia of chronic disease?
- Treat underlying cause
- EPO
- Iron
- Hepcidin and inflammatory markers inhibitors
