Anaemia Recap Flashcards
How do we define anaemia?
Reduction in haemaglobin concentration below that which is optimum for that individual
How can we diagnose anaemia?
History/ exam/ clinical context FBC Retic count Blood film Haematinics (ferritin/ B12/ folate) Bone marrow biopsy Special tests; HbA2, HLPC
What can cause a decreased RBC production?
Hypoproliferative; reduced erythropoiesis
Maturation issues; cytoplasmic (impaired Hb)
Nuclear (impaired division)
What is the retic count a useful marker of?
Red cell production; will be increased in haemolysis and acute blood loss
What are the productions of red cell destruction seen in haemolysis?
Increased unconjugated serum bilirubin
Increased urinary urobilinogen
Splenomegaly
What is the difference between MCV and MCH?
MCV; cell size
MCH; cell Hb content
What can cause hypochromic microcytic anaemia?
Iron deficiency
Haem defects; lead poisoning, congenital sideroblastic
Globin defects; thalassaemia
(Rarely; anaemia of chronic disease)
What can cause macrocytic anaemias?
Nuclear maturation defects; B12/ folate (megaloblastic), myelodysplasia, chemo
Agglutination
Reticulocytosis
What can cause macrocytosis without significant anaemia?
Hypothyroidism
Alcohol
Liver dx
What can cause normocytic normochromic anaemia?
Marrow failure; drug induced, aplastic anaemia
Hypometabolic
Marrow infiltration; metastatic malignancy, fibrosis
Renal impairement
Chronic disease
Why will renal impairment lead to normochromic normocytic anaemia?
Failure of EPO production
Describe the pathogenesis of anaemia of chronic disease?
Chronic inflammation
Pro-inflammatory cytokines
IL-6 induces increased hepcidin levels which decreases serum iron
Decreased EPO producto n
Decreased marrow response
RBC life span decreases and haemophagocytosis via macrophages is induced
Why can anaemia of chronic disease sometimes be microcytic?
If predominant mechanism is through hepcidin stimulation
Decreased release of iron from macrophages
Results in a low transferrin saturation despite normal/ raised ferritin
This WILL response to IV iron
How can iron deficiency and anaemia of chronic disease be distinguished?
Both have reduced serum iron
Anaemia of CD; reduced transferrin
Iron deficiency; normal or increased transferrin
Both have decreased % transferrin saturation
IDA = DECREASED FERRITIN
ANAEMIA OF CD = INCREASED FERRITIN
MCV reduced in iron deficiency and tends to be normocytic in anaemia of CD
In what circumstances can nucleated red cells appear int the blood?
Bone marrow damage or stress Severe anaemia Thalassaemia Hypoxaemia Myelomas Leukaemias Lymphomas Myelofibrosis
Why does haemoglobin change colour?
When iron is oxygenated (Fe3+) it becomes red
When iron is deoxygenated (Fe2+) is becomes blue
Electrons are added to the D orbitals changing its energy levels. This affects the absorption of light
What can result in red cell membrane damage
Mutational; hereditary spherocytosis, zieve’s syndrome (haemolysis related to alcoholic liver disease)
Autoimmune haemolytic anaemia
Infection; DIC, sepsis
Mechanical; severe burns, HUS, heart valve, TTP
What are drug causes of oxidative damage in the RBC?
Quinines
Antimalarials
Fava beans
Dapsone
What are the clinical manifestations of oxidative damage of RBC?
Tiredness, lethargy, pale gums, pallor
Jaundice
Heinz bodies
What are the signs and symptoms of microcytic hypochromic anaemia?
Tachycardia, tachypnoea, extra heart sound, pallor
Palpitations, lethargy, fatigue, TATT, tinnitus, somnolence
What blood cells aside from the RBC are produced in the bone marrow?
Granulocytes; neutrophils, basophils, eosinophils, platelets
Agranulocytes; leukocytes, monocytes
How can B12 deficiency present?
Pallor
Mild jaundice
Red beefy tongue
Reduced vibration and proprioception
