Haematology Flashcards
IRON DEFICIENCY ANAEMIA
What is the physiology of iron?
- Bone marrow requires iron to produce Hb which is mainly absorbed in the duodenum + proximal jejunum enhanced by vitamin C + inhibited by tannin (tea)
IRON DEFICIENCY ANAEMIA
What are some causes of iron deficiency anaemia?
- Increased loss = menorrhagia, GI bleeding (?colorectal cancer), hookworm
- Inadequate intake/increased needs = poor diet, puberty growth, pregnancy
- Malabsorption = IBD, coeliac disease
IRON DEFICIENCY ANAEMIA
What is the clinical presentation of iron deficiency anaemia?
- Symptoms = fatigue, SOB, headaches, dizziness, palpitations
- Generic signs = (conjunctival) pallor, tachycardia + tachypnoea
- Pica = consumption of non-food materials
- Koilonychia, angular stomatitis, atrophic glossitis + brittle hair/nails
IRON DEFICIENCY ANAEMIA
What investigations would you do in iron deficiency anaemia?
- FBC = low Hb, low MCV + normal reticulocytes
- Blood film = hypochromic microcytic RBCs, target cells + pencil poikilocytes
- Iron studies
- ?2ww suspected colorectal cancer for colonoscopy if ≥60
IRON DEFICIENCY ANAEMIA
What would iron studies show in iron deficiency anaemia?
- Low = ferritin, iron + transferrin saturation (proportion of transferrin bound to iron)
- High = total iron binding capacity (total space on transferrin for iron to bind)
IRON DEFICIENCY ANAEMIA
What is the management of iron deficiency anaemia?
Side effects of the treatment?
- Diet = red meat, oily fish, green veg (broccoli, spinach), dried fruit (raisins)
- PO iron supplementation (ferrous sulfate/fumarate)
- Note SE: constipation, black coloured stools, nausea + abdo pain
THALASSAEMIA
What is thalassaemia?
What is the epidemiology?
- Autosomal recessive disorders caused by ≥1 gene defect, resulting in a reduced rate of production of ≥1 alpha/beta globin chains making RBCs more fragile
- Common in Mediterranean, Middle East + East Africa
THALASSAEMIA
How is alpha thalassaemia classified?
- 1–2 alpha globin alleles affected = hypochromic + microcytic but Hb often ok
- 3 = hypochromic microcytic anaemia with splenomegaly (Hb H disease)
- 4 = death in utero due to foetal hydrops
THALASSAEMIA
How is beta thalassaemia classified?
- Minor = 1 abnormal and 1 normal gene
- Intermedia = 2 defective or 1 defective + 1 deletion
- Major = homozygous for deletion genes
THALASSAEMIA
What is the clinical presentation of beta thalassaemia…
i) minor?
ii) intermedia?
i) Mild microcytic anaemia which only needs monitoring
ii) Jaundice + hepatosplenomegaly, monitoring ± blood transfusions
THALASSAEMIA
What is the clinical presentation of beta thalassaemia major?
- Presents in first year with failure to thrive, hepatosplenomegaly, jaundice, microcytic anaemia
- Extramedullary haemopoiesis = hepatosplenomegaly, bone marrow expansion (maxillary overgrowth + frontal bossing)
- HbA2 + HbF raised but HbA absent
THALASSAEMIA
What investigations would you do in thalassaemia?
How do you differentiate from iron deficiency anaemia?
What investigation is diagnostic?
- FBC = low Hb + MCV
- Film = hypochromic + microcytic RBCs
- Serum ferritin NORMAL
- Hb electrophoresis = diagnostic
- DNA testing via CVS
THALASSAEMIA
What is the management of thalassaemia?
What is a complication of this and how is it managed?
- Blood transfusions (regular in beta thalassaemia major)
- Require iron chelation with desferrioxamine to avoid overload + organ failure (cardiomyopathy, cirrhosis, DM, arthritis)
- Splenectomy ± curative bone marrow transplant
B12 DEFICIENCY ANAEMIA
What is the physiology of vitamin B12?
- Absorption occurs in the terminal ileum + is intrinsic factor (secreted by gastric parietal cells) dependent for transport across the intestinal mucosa
B12 DEFICIENCY ANAEMIA
What are some causes of B12 deficiency anaemia?
- Malabsorption = Crohn’s, coeliac, ileal resection
- Dietary (vegans) as B12 high in fish, meat, dairy
- Autoimmune (pernicious) = atrophic gastritis leads to destruction of parietal cells > intrinsic factor deficient
B12 DEFICIENCY ANAEMIA
What is the clinical presentation of B12 deficiency anaemia?
- Anaemia Sx = fatigue, SOB, headaches, dizziness, palpitations
- B12 deficiency = dorsal column affected (proprioception, loss of vibration, peripheral neuropathy paraesthesia, neuropsych mood disturbance), glossitis (beefy-red sore tongue)
B12 DEFICIENCY ANAEMIA
What investigations would you do in B12 deficiency anaemia?
- FBC = low Hb, high MCV (macrocytic, megaloblastic)
- Haematinics = low B12
- Blood film = hypersegmented neutrophil nuclei
- Intrinsic factor Ab specific for pernicious, may have gastric parietal cell Ab
B12 DEFICIENCY ANAEMIA
What are some differentials of macrocytic anaemia which are normoblastic?
- Alcohol
- Liver disease
- Hypothyroidism
- Myelodysplasia
- Reticulocytosis
B12 DEFICIENCY ANAEMIA
What should you check before managing B12 deficiency anaemia?
What is the management of B12 deficiency anaemia?
- Folate > do not give folic acid as can cause subacute combined degeneration of the cord = distal sensory loss, ataxia + mixed U/LMN signs
- Initially IM hydroxocobalamin then maintenance with PO cyanocobalamin if diet-related or IM hydroxocobalamin every 2–3m
FOLATE DEFICIENCY ANAEMIA
What is the pathophysiology of folate deficiency anaemia?
- Develops over 4m of deficiency due to bodily reserves
- Folate is absorbed in the proximal jejunum
FOLATE DEFICIENCY ANAEMIA
What are some causes of folate deficiency anaemia?
- Increased demand = pregnancy, malignancy, haemolysis
- Decreased intake = poor diet (green vegetables)
- Decreased absorption = coeliac, Crohn’s, jejunal resection
FOLATE DEFICIENCY ANAEMIA
What is the clinical presentation of folate deficiency anaemia?
- Anaemia = fatigue, SOB, headaches, dizziness, palpitations
- NO neuropathy
FOLATE DEFICIENCY ANAEMIA
What investigations would you do in folate deficiency anaemia?
What’s the management?
- FBC = low Hb, high MCV, macrocytic megaloblastic
- Haematinics = low folate
- PO folic acid 5mg OD
HEREDITARY SPHEROCYTOSIS
What is the pathophysiology of hereditary spherocytosis?
- Autosomal dominant mutation of structural RBC membrane proteins leading to removal of abnormal membrane as it passes by spleen resulting in reduced SA:V + becoming spheroidal leading to extravascular haemolysis + destroyed by spleen