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By Tiffany Shaw MBChB II 2002

Approach to Anaemia. By Tiffany Shaw MBChB II 2002. Anaemia – Definition. Reduced Hb concentration in blood Compared to normal range for the particular gender + age NOT reduced red cell count (unlike leucopenia or thrombocytopenia, which is defined by low counts). Symptoms:

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By Tiffany Shaw MBChB II 2002

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  1. Approach to Anaemia By Tiffany Shaw MBChB II 2002

  2. Anaemia – Definition • Reduced Hb concentration in blood • Compared to normal range for the particular gender + age • NOT reduced red cell count (unlike leucopenia or thrombocytopenia, which is defined by low counts)

  3. Symptoms: SOB on exertion Tiredness Headache Angina Signs: Pallor Tachycardia +/- Jaundice +/- Koilonychia +/- Splenomegaly +/- Sore corners of mouth Symptoms + Signs Depends on cause of anaemia

  4. Symptom + Signs • Koilonychia = nail change, usually seen in Fe deficiency. Nails become brittle, spoon shaped, and ridged. • Sore mouth corners = angular cheilosis, seen in Fe, B12, or folate deficiency. • Jaundice = due to increased bilirubin production as a result of increased haemolysis (haemolytic anaemia)

  5. Investigation for Suspected Anaemia Full Blood Count • Hb concentration • Haematocrit • Red cell count • MCV (mean cell volume) • MCH (mean cell haemoglobin) • White cell count • Differential white cell count (neutrophils, lymphocytes, monocytes, eosinophils, basophils) • Platelet count

  6. Investigation for Suspected Anaemia • Hb concentration: confirms anaemia + assesses severity • MCV: is this microcytic, normocytic, or macrocytic? • MCH: is this normochromic or hypochromic? • Other cell counts: is this isolated anaemia or pan-cytopenia? Microcytic = MCV < normal (76) Normocytic = MCV normal (76 – 96) Macrocytic = MCV > normal (> 96)

  7. Classification Based on MCV • Microcytic ~ • Fe deficiency • Thalasaemia • Sideroblastic • Chronic disease • Normocytic ~ • Chronic disease • Haemolysis • Marrow disease • Macrocytic ~ • B12 deficiency • Folate deficiency • Liver disease • Marrow disease • Haemolysis (MCV pushed up by reticulocytosis)

  8. Investigating Microcytic Anaemia Clue One --- Iron Studies • Serun Iron (free Fe) • Ferritin (stored Fe) • Iron Binding Capacity IBC (transferrin) NB: Transferrin is the iron binding protein in blood and amount of transferrin reflects capacity to bind Fe.

  9. Investigating MicrocyticAnaemia Thalasaemia, Sideroblastic: • Fe Deficiency: • Low serum Fe • Low ferrtin • Increased IBC • NB: Increased IBC kind of reflects body’s attempt to grab more Fe. • Chronic Disease: • Low serum Fe • Normal ferritin • Reduced IBC • NB: Problem here is a block in the utilisation of Fe. • High serum Fe • High ferritin • Normal IBC • NB: There are defects in Hb production, therefore excessive Fe.

  10. Investigating MicrocyticAnaemia Clue Two --- Blood Film Exam • Fe deficiency  Microcytes, Target cells, Pencil cells • Chronic disease  Variable, depends on cause • Thalasaemia  Microcytes, Target cells • Sideroblastic  Dimorphic (both normal RBC and microcytic ones), Siderotic granules in RBC

  11. Investigating MicrocyticAnaemia Clue Three --- Special Tests • Hb electrophoresis: for thalasaemia • DNA analysis: for hereditary causes (e.g. thalasaemia) • Bone marrow: sideroblastic anaemia shows ringed sideroblasts in marrow

  12. Investigating Normocytic Anaemia Clue one --- Reticulocyte Count • Increased  Haemolysis • Normal or decreased  Chronic disease Marrow disease

  13. Investigating Normocytic Anaemia Clue Two --- Other Cell Counts • Normal  Chronic disease probably • Abnormal  Marrow disease likely

  14. Investigating Normocytic Anaemia Clue Three --- Special Tests • Bone marrow biopsy for ? marrow diseases • Other tests for ? chronic diseases • U + E • Creatinine • LFT • Thyroid function …etc.

  15. Investigating Macrocytic Anaemia Clue One --- Reticulocyte Count • Increased  Haemolysis • Normal or decreased  B12 deficiency Folate deficiency Liver disease Marrow disease

  16. Investigating MacrocyticAnaemia Clue Two --- B12 / Folate Level • Low  Deficiency • Normal  Liver disease Marrow disease NB: For B12, folate, and Fe deficiency, further investigations must be made to determine the cause of deficiency, so that appropriate therapy can be instituted.

  17. Investigating MacrocyticAnaemia Clue Three --- Other Cell Counts • Normal  liver disease probably (confirm with LFT, liver u/s…etc.) • Abnormal  probably marrow disease (confirm with marrow biopsy…etc.)

  18. Fe Deficiency Physiology: • Source of Fe = both in animal + vegetable products • Animal Fe more easily absorbed • Site of absorption = proximal jejunum • Vit C enhances absorption • Daily loss = urine, skin, faeces, hair, menstrual blood loss

  19. Fe Deficiency Findings associated with Fe deficiency: • Anaemia (microcytic) • Koilonychia • Angular cheilosis • Glossitis • Hair thinning • Abnormal Fe studies (see before)

  20. Fe Deficiency Causes: • Blood loss • Increased demand • Inadequate intake • Malabsorption • Menorrhagia • GI bleed • Haematuria …etc.. • Pregnancy • Growth • Gastrectomy • Coeliac disease

  21. Fe Deficiency Mx: • Treat underlying cause if possible (e.g. bleed) • Oral Fe replacement – Ferrous sulphate best, gluconate second • Taken before meals TDS • Continue for 4-6/12 • Reticulocytosis typically begins 7 days after Rx • Fe replacement IV or IM if oral not possible

  22. Thalasaemia • Hereditary anaemia • Impaired production of components of the globin • Classified into a and b depending on which chain is deficient • Lack of a chain = a thalasaemia • Lack of b chain = b thalasaema

  23. a Impaired production of a chain in the globin. Severity depends on number of genes deleted 4/4 = hydrops fetalis (intrauterine death) 3/4 = haemoglobin H disease (severe anaemia) 1- 2/4 = a trait (mild anaemia) b Impaired production of b chain in the globin Major = complete failure of production (severe anaemia) Intermedia = partial failure (moderate anaemia) Minor = asymptomatic or mild anaemia Thalasaemia

  24. Diagnosis: Microcytic anaemia Blood film examination Hb electrophoresis DNA analysis Associated findings: Usual signs of anaemia Failure to thrive Hepatosplenomegaly Expansion of the skull High serum + storage Fe Thalasaemia

  25. Thalasaemia Mx: • Transfusion (packed red cells) prn • Iron chelation therapy with DFX • Splenectomy prn • Bone marrow transplantation (definitive Rx) • Genetic counseling

  26. Sideroblastic Anaemia • Defect of haem synthesis • Increased Fe present as granules arranged in a ring around nucleus of developing RBC in marrow (ringed sideroblasts) • Peripheral blood shows microcytic hypochromic RBC • May be hereditary or acquired

  27. Sideroblastic Anaemia Causes: • Hereditary type (X-linked) • Alcohol • Radiation therapy • Lead poisoning

  28. Sideroblastic Anaemia Mx: • Transfusion prn • Iron chelation therapy • Some benefit from Vit B6 (esp the hereditary type)

  29. Haemolytic Anaemia Common types: • Autoimmune • Alloimmune • G-6PD deficiency • Pyruvate kinase deficiency • Hereditary spherocytosis • Thalasaemia (discussed before) • Sickle cell anaemia Normocytic Microcytic

  30. Autoimmune • Autoantibodies against self RBC • Divided into warm + cold types, depending on which temperatures antibodies work best under • May be idiopathic or secondary to other conditions • +ve for direct Coomb’s test

  31. Warm Type Max at 37 degrees Ig G Get microcytosis + spherocytosis Splenomegaly common Cold Type Max at 4 degrees Ig M Autoimmune

  32. Warm Type Causes: Idiopathic c.t. disorder (SLE) CLL Drug induced (methyl dopa) Cold Type Causes: Idiopathic Infection (e.g. glandular fever, Mycoplasma infection) Lymphoma Autoimmune

  33. Warm type Mx: Steroids Transfusion prn Splenectomy if steroids fail Other immunosuppressives Cold type Mx: Avoid cold environment Immunosuppressives (chlorambucil, cyclophosphamide) Transfusion prn Autoimmune

  34. Alloimmune • Mismatched blood transfusion • Haemolytic disease of the newborn • Post bone marrow transplantation • Post organ transplantation

  35. Hereditary Spherocytosis • Hereditary anaemia • Most common one in Caucasian • Autosomal dominant • Defect in RBC membrane • RBC becomes spherical • Therefore destroyed prematurely in spleen • Splenomegaly common

  36. Hereditary Spherocytosis Special test --- Osmotic Fragility Test • Spherical RBC  increased volume : surface area ratio • More prone to lysis by osmosis • Measure degree of lysis of RBC in different concentrations of saline  spherical ones lyse more • Therefore confirm spherocytosis

  37. Hereditary Spherocytosis Mx: • Splenectomy to stop destroying RBC prematurely

  38. G-6PD Deficiency • G-6PD = enzyme required to generate ATP to maintain shape of RBC • Deficiency  RBC more susceptible to oxidation stress, e.g. ingestion of certain drugs / fava beans • Haemolysis occurs with such ingestion • Normal at other times

  39. 6-GPD Deficiency Mx: • Stop offending drugs / fava beans • Transfusion prn during attacks

  40. Physiology: Source of B12 = food of animal origin Storage = in liver, enough for 2 – 4 years Absorption = in terminal ileum Vit B12 ingested Binds to “R protein” in saliva, gastric juice IF secreted by parietal cells releases Vit B from R protein Form IF-Vit B12 complex Complex absorbed in terminal ileum Transcobolamin in plasma strips off Vit B12 and transport to tissues Vit B12 Deficiency

  41. Diagnosis: Macrocytic anaemia Low B12 level Associated findings: Features of anaemia Mild jaundice Glossitis Angular cheilosis Neuropathy (often tingling in feet +/- visual or psych disturbance) Vit B12 Deficiency

  42. Vit B12 Deficiency Causes: • Inadequate intake (e.g. vegan) • No IF (gastrectomy, pernicious anaemia) • Malabsorption (ileal resection, Crohn’s disease)

  43. Vit B12 Deficiency Pernicious Anaemia: • Autoandibodies develop against parietal cells or intrinsic factors • Therefore no IF • Can’t absorb Vit B12 • Peak incidence at 60 years old

  44. Vit B12 Deficiency Distinguish between no IF & ileal problems: • Hx (e.g. gastrectomy) • Test for autoantibodies against parietal cells or IF • Radioactive Vit B12 study Give radio-labelled Vit B12 +/- IF. IF corrects gastric problems, but not ileal problems.

  45. Vit B12 Deficiency Mx: • Correct underlying cause if possible (e.g. adequate intake) • IM Vit B12 injection • 6 injections to replace deficit (1 every 2 –3 days) • Maintenance (1 injection 3/12)

  46. Folate Deficiency Physiology: • Source = green vegetables + animal liver • Body store = 4/12 supply • Absorption = through proximal jejunum

  47. Diagnosis: Macrocytic anaemia Low folate level Associated findings: Features of anaemia Mild jaundice Glossitis Angular cheilosis No neuropathy!! Folate Deficiency

  48. Folate Deficiency Cause: • Inadequate intake • Malabsorption (coeliac disease, bowel resection) • Drug induced (anti-convulsant)

  49. Folate Deficiency Mx: • Treat underlying cause if possible (e.g. coeliac disease) • Folate replacement • Oral folate 5 mg OD for 4-6/12

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