Anaemia Flashcards
Define anaemia (1½-3) (Super NB)
A decrease in the circulating haemoglobin per unit volume of blood when compared with the correct reference population for that patient (correct age and sex) OR A blood haemoglobin concentration lower than normal for the age and sex of the patient.
List six (6) clinical features that may be present in patients with anaemia (3)
Tiredness, Fainting, Pallor, Tachycardia, Shortness of breath, Weakness, Palpitations, Headaches, Intermittent claudication, Confusion, Bounding pulse
Classify the morphological types of anaemia (3x½). Give three examples (causes) of each type (3x3x½) AND state one laboratory investigation that would assist you to make the diagnosis of the cause of the anaemia (3x3x½) [10½] (Super NB)
Hypochromic (MCHC) Microcytic (MCV) Anaemia
Iron deficiency (acquired) - Iron studies
Thalassaemia (inherited) - Haemoglobin studies
Sideroblastic anaemia - Bone marrow for ring sideroblasts
Anaemia of chronic disease/inflammation (can be normocytic too)
Lead poisoning
Macrocytic (MCV) Anaemia Megaloblastic anaemia o Vit. B12 deficiency - Serum B12 level o Folic acid deficiency - RBC folate level Liver disease - Liver function tests Myelodysplastic Syndrome Drugs e.g. ARVs Hypothyroidism Pregnancy
Normochromic Normocytic Anaemia (Normal MCHC & MCV)
Haemolytic anaemia - Blood film morphology, reticulocyte count, haptoglobin
Anaemia of chronic disease - Iron studies, soluble transferrin receptor
Renal disease - Serum urea and creatine
Bone marrow failure
Anaemia can be classified according to the red blood cell size or mechanism. Name four (4) mechanisms that result in anaemia and list one clinical or laboratory finding that indicates/ suggests each causative mechanism (8)
Failure of bone marrow production: Low reticulocyte
Blood loss: Clinical evidence of blood loss, ed reticulocyte
Increased destruction: Increased retic. count (polychromasia), Haemolytic screen (Morphology)
Pooling or sequestration: Splenomegaly
Five specific signs associated with a particular type of anaemia are listed below. Please indicate for each sign which subtype of anaemia it would suggest (2½)
a) Jaundice
b) Loss of proprioception and vibration sense
c) Koilonychia (spoon nails)
d) Leg ulcers in conjunction with haemolytic anaemia
e) Bone deformities in conjunction with haemolytic anaemia
Jaundice. Haemolytic anaemia
Loss of proprioception and vibration sense. Vit B12 deficiency
Koilonychia (spoon nails). Iron deficiency
Leg ulcers in conjunction with haemolytic anaemia. Sickle cell anaemia
Bone deformities in conjunction with haemolytic anaemia. Beta thalassaemia
Mrs Xaba is a 50-year-old anaemic patient. Placed on iron supplementation and educated about menopause. Six months later, despite continuing with iron supplements, tiredness persists and notices weight loss.
State the type(s) of anaemia suggested by these biochemical findings (2x½ = 1)
Iron deficiency & anaemia of chronic disease.
Briefly explain the change seen in: (4x1 = 4) (CPATH) Transferrin
Ferritin
Soluble Transferrin Receptors
Hepcidin
Transferrin. decreased due to chronic inflammation
Ferritin. increased with inflammation & decereased with iron deficiency,
Soluble transferrin receptors. increased with iron deficiency,
Hepcidin. increased with inflammation
Mrs April is a 90-year-old living with her 80-year-old sister. She is generally frail but on one morning she is particularly pale and short of breath and dizzy. Enlarged heart and a hyperdynamic circulation. Hb is 6g/dL.
If Mrs April has a microcytic, hypochromic anaemia and a positive stool occult blood test, state the important investigation you should refer her for (½) (CPATH)
Colonoscopy
List three (3) additional investigations you may need to perform to determine the aetiology for the above anaemia, seeing as you have already ascertained that she is not a strict vegan (1½) (CPATH)
Plasma anti-parietal, Anti-intrinsic factor Abs, Gastroscopy plus gastric biopsy, Small bowel imaging studies
If Mrs April has a macrocytic anaemia, is a teetotaller and has normal red cell folate levels, state the type of anaemia that must be excluded (½) (CPATH)
Vit B12 deficiency anaemia
Samantha Scott is a 21-year-old anaemic patient. Menses have been heavier than usual for the past few months. She is also a vegan and drinks ten (10) mugs of tea per day. On examination she is pale with a tachycardia of 102 bpm.
From the case history, identify two (2) possible causes for Ms Scott’s anaemia, and for each state the health or lifestyle factor that may have led to this anaemia (2)
Iron deficiency from blood loss due to heavy menses & from excessive tea drinking, Vit B12 deficiency from vegan diet
Explain the possible relevance of excessive tea-drinking in this case (3) (CPATH)
Tea is rich in tannins which bind elemental iron (as opposed to haem iron) in the bowel lumen, preventing its absorption. In a vegan, elemental iron is the only form of dietary iron available, and could be a contributory factor (along with blood loss) to her iron-deficiency anaemia.
Ms Kowa (folate deficient) says her new baby boy has been jaundiced since birth. He is also anaemic and is found to have G6PD-deficiency. Reticulocyte counts performed.
Interpret and explain these results, considering what you know about each patient (3)
Ms Kowa is deficient in folic acid and therefore cannot mount a RCC, so her result is very low. Baby Kowa has a haemolytic anaemia & his bone marrow is trying to compensate for this by releasing increased numbers of reticulocytes, so his result is high.
In what form is iron… & Indicate the total quantity of iron (in mg or g) normally present in each form (2) (CPATH)
a) Carried in plasma
b) Stored in cells
a) Carried in plasma. Bound to transferrin (~3mg)
b) Stored in cells. Within the storage protein ferritin (~1g)
Describe the function of transferrin and name one condition other than IDA in which transferrin is decreased (2) (CPATH)
Transferrin transports iron in circulation – almost all iron is circulation is bound to transferrin
Conditions: Protein loss i.e. protein losing enteropathy or nephrotic syndrome, Liver disease
Transferrin & ferritin are acute phase responders. State in which direction they will change (increase, decrease, no change) in the presence of inflammation (1) (CPATH)
Transferrin - decrease
Ferritin - increase
List four (4) groups of causes of IDA, and state two (2) specific examples for each (½x12 = 6)
Chronic blood loss (bleeding peptic ulcer, heavy menses)(aggravated by NSAIDS), ed demands (pregnancy, premature infants), Malabsorption (gastrectomy), Undernutrition (poverty)
List six (6) biochemical and haematological markers of iron deficiency (3) (CPATH) (Super NB)
Decreased Serum iron, Increased Serum transferrin (or total binding capacity), Decreased% Transferrin saturation, DecreasedSerum ferritin, Decreased Hb
Blood smear features: Hypochromia (decreased MCHC), Microcytosis (decreased MCV), Pencil cells, Occasional target cells, Thrombocytosis
In the presence of inflammation, state which test would be useful in identifying iron deficiency anaemia (½) (CPATH)
Soluble transferrin receptors
Explain why iron deficiency typically gives rise to small red cells (microcytosis) whereas folate deficiency gives rise to larger than normal red cells (macrocytosis) (2) (CPATH)
Fe required to synthesise haemoglobin, the major protein in RBCs (>95%). Insufficient Hb ‘filling’ leads to small red cells. Folate is required for DNA synthesis; thus insufficient folate impairs division of red cell precursors (normoblasts) which continue to grow without dividing, leading to larger than normal mature red cells.
Name an inherited disease that gives rise to a microcytic anaemia, and name two (2) laboratory tests used to distinguish it from iron deficiency anaemia (2) (CPATH)
Thalassaemia (α or β)
Any 2: Serum Fe, total iron binding capacity (TIBC), transferrin, ferritin, relative rates of α or β-globin chain synthesis in reticulocytes or bone marrow cells
The haematological findings below are compatible with both iron deficiency and thalassaemia.
Identify the underlying defect in thalassaemia, and show how serum iron studies can distinguish the two conditions by completing the following table (use ↓↓ (very low), ↓ (low), N (normal), ↑ (high), or ↑↑ (very high) rather than actual numbers) (10) (CPATH)
Deletion of one or more β or α globin genes, hence impaired haemoglobin synthesis.
Mr Bonga Shoba is 54 years old. Very dark stools for several weeks. Been feeling tired when he climbs the stairs to his flat or runs for a taxi. On examination, pale, has mild tachycardia (90/min) and a poorly defined, tender mass in his epigastrium. The initial laboratory results show: Reticulocyte count: 0.1% (N = 0.5-2.5%), Occult Blood test: (+)
State the most likely specific cause of Mr Shoba’s anaemia and its probable underlying cause, giving one (1) clinical and three (3) laboratory features to justify your answers (3)
Cause: Iron deficiency. Underlying cause: GIT blood loss.
Clinical feature: Dark stools. Lab features: Microcytosis, Hypochromia, Positive stool occult blood
Would the level of soluble transferrin receptors be normal, increased or decreased in Mr Shoba’s case (1) (CPATH) [iron deficiency due to blood loss]
Increased
Explain the pathogenesis of beta-thalassaemia briefly and list four (4) smear features of beta-thalassaemia major (3)
Genetic disease/Congenital. Decreasing the production of Beta chains of globin molecule in haemoglobin
Hypochromia, Microcytosis, Target cells, Basophilic stippling, Nucleated red cells
Briefly describe the mechanism of anaemia in beta thalassaemia major (3)
Defective synthesis of beta chains results in an excess of alpha chains. These precipitate in the cell, causing the developing red cell to be destroyed in the bone marrow (intramedullary haemolysis). Those red cells which survive have a decreased amount of Hb compared to normal, hence the hypochromic microcytic picture.
