Introduction and Classification of Anaemia

PALI Haematology Session

3rd October 2012

Christopher Mullen

• Introduction• Classification• The Hypochromic Anaemias• Megaloblastic and other macrocytic anaemias• Haemolytic anaemias• Genetic disorders of haemoglobin• Investigation of the anaemic patient• Exam paper cases

Overview of Presentation

• Reduction in haemoglobin/red cell concentration in the blood relative to the patient’s age and sex.

Introduction

Age Mean haemoglobin (g/dL)

1 month 140

6 months – 2 years 120

2 – 6 years 125

6 – 12 years 135

12 – 18 year old females 140

12 – 18 year old males 145

Adult females 140

Adult males 155

• Prevalent worldwide, especially among females and children

• A reduction in the blood’s oxygen carrying capacity leading to tissue hypoxia

• Clinical features relate to compensatory mechanisms– Cardiovascular: palpitations, chest pain, tachycardia,

intermittent claudication– Skin: vasoconstriction and redistribution of blood flow

General Clinical Features

• Morphological classification– Dependent on red cell indices i.e. MCV and

MCH/MCHC– Macrocytic vs. normocytic vs. microcytic– Hypochromia vs. normochromia

• Aetiological classification – Haemorrhage– Haemolytic– Insufficient/ineffective haemopoiesis

Classification

Differential Diagnosis• Iron deficiency

– The most common cause of anaemia worldwide

– Hypochromic, microcytic anaemia (↓MCV, ↓MCHC)

• Thalassaemia• Sideroblastic anaemia• Lead poisoning• Anaemia of chronic disease

(sometimes) • Acronym - TAILS

The Hypochromic Anaemias

Clinical Features• Pallor of skin and

mucous membranes• Painless glossitis• Angular stomatitis• Koilonychia

Iron Deficiency Anaemia

Aetiology• Chronic blood loss – uterine

and gastrointestinal• Dietary deficiency (rarely

alone)• Increased demand –

pregnancy, lactation, infancy etc.

• Gastrointestinal disease e.g. coeliac, atrophic gastritis, gastrectomy

• Helminth infections

Aetiology

Iron deficiency anaemia is not a diagnosis – an underlying cause must be sought• Blood film• Iron studies – increased total

iron binding capacity (TIBC), low serum ferritin

• Men and post-menopausal women GI blood loss occult blood testing, endoscopy if suspicious

• Uncommon causes – CXR, stool microscopy, cell autoantibodies

Investigations

• Identify and treat underlying cause(s)

• Ferrous sulphate

• Parenteral iron where appropriate e.g. coeliac disease, Crohn’s disease

Management

• Associated with a variety of malignant and inflammatory diseases

• Normocytic and normochromic (or slightly microcytic anaemia)

• Cytokines reduced red cell lifespan and impair haemopoesis

Anaemia of Chronic Disease

• MCV abnormally large (>98 fL)– Alcohol– Liver disease– Hypothyroidism– Myeloma and

paraproteinaemia– Myelodysplasia– Reticulocytosis– Pregnancy– Cytotoxic drugs e.g.

azothioprine

Macrocytic anaemias

• Immature red cells display delayed nucleus maturation

• Due to defective DNA synthesis

• Nearly always caused by folate/B12 deficiency

Megaloblastic anaemia

• Absorbed in terminal ileum (requires intrinsic factor)

• Acts as a co-enzyme• Deficiency takes 2 years to

develop• Pernicious anaemia –

associated with autoimmune diseases. Autoimmune attack against parietal cells/intrinsic factor

B12 deficiency

• Required for synthesis of thymidine monophosphate (dTMP)

• Causes– Poor diet– Increased demand –

pregnancy (NTDs)– Haematological disease– Inflammatory disease– Malabsorption

Folate Deficiency

• Lemon skin (jaundice and pallor)

• Glossitis• Subacute combined

degeneration of the cord in severe B12 deficiency

• Macrocytic anaemia• Mildly reduced WCC and

platelets• Hypersegmented neutrophils• Raised unconjugated bilirubin

and LDH

Clinical Features

• Serum assays for folate and B12

• Parietal cell and intrinsic factor antibodies

• Intestinal biopsy, anti-TG if suspicious for coeliac disease

Further Investigations

• Anaemia due to increased red cell destruction

• Can be hereditary or acquired

• Hereditary are due to intrinsic defects within red cells

• Acquired are due to changes in red cell environment

Haemolytic anaemias

Hereditary• Membrane defects

– Hereditary spherocytosis– Hereditary elliptocytosis

• Enzyme defects– Glucose-6-phosphate

dehydrogenase deficiency– Pyruvate kinase deficiency

• Defects in haemoglobin– Haemoglobin C, haemoglobin

S, unstable haemoglobin

Acquired • Immune

– Autoimmune warm– Autoimmune cold– Drug-associated– Transfusion-associated

• Infections– Malaria

• Secondary to liver and renal disease

• PNH

Classification

• Pallor of mucous membranes

• Jaundice• Splenomegaly• Damaged red cells on

blood film• Erythroid hyperplasia of

bone marrow • Bilirubinaemia and

increased urinary urobilinogen

Clinical Features

Intravascular Haemolysis• Breakdown of red blood

cells in the circulation• Haemoglobin is released

(haemoglobinaemia)• Haptoglobins are saturated• Haemoglobinuria• Haemosiderinuria• Methalbuminaemia

Extravascular Haemolysis• Red cells are broken down

by macrophages or the reticuloendothelial system

Chemical Features of Intravascular Haemolysis

• Genetic disorder• Reduced rate of synthesis of α or

β globin chains• Common in Mediterranean and

South-East Asia• Varies depending on number of

genes rendered inactive• Marrow hyperplasia in β-

thalassaemia gives rise to characteristic facies

• Diagnosed by haemoglobin electrophoresis/high performance liquid chromatography

• Inheritance of the sickle β-globin gene

• Homozygotes (Hb SS) are the most common severely affected patients

• Severe haemolytic anaemia associated with “crises”

• Diagnosed via haemoglobin electrophoresis

Genetic disorders of haemoglobin – Sickle Cell Anaemia

You are a GP trainee and Mrs J, a 24 year old lady, presents to the clinic. She has just moved to your area, her notes haven’t arrived at the surgery, and she is complaining of tiredness. She doesn’t wish to be fully examined but clinically you suspect anaemia and you arrange a full blood count, results of which are shown below.

She returns to health centre and this time you notice that she is also slightly icteric. Urine analysis shows urobilinogen but no bilirubin. There is no glycosuria, haematuria or pyuria. The serum bilirubin concentration is 65 Kmols/l (normal range 15 – 22 Kmols/litre).

TEST RESULT REFERENCE RANGE

Hb

9.3g/dL

11.5-13.5

WCC

8.9 x 109/L

4-11 x 109/L

Platelets

304 x 109/L

150-400 x 109/L

MCV

104 Fls

80-96 Fls

1. Apart from investigations for haemolysis, list two other investigations, explaining your reason for doing the test to help elucidate the cause for producing the increased MCV (2 marks)

2. Apart from the results in the previous slide, list two biochemical or haematological abnormalities that may occur in haemolysis

3. Explain in less than fifty words, why an increase in serum bilirubin will not lead to increased renal excretion of bilirubin. (2 marks)

4. List two defects in the red cells which can cause haemolysis and give one example of each (2 marks)

5. It transpires that Mrs J had a splenectomy for this problem as a child and that she subsequently had no follow-up or treatment after this procedure. List two organisms you would wish to vaccinate against. (2 marks)

6. List two pieces of advice you would wish to instigate in patients following a splenectomy. (2 marks)

• A 32 year old woman, who is a mother of four children under aged 6 years, presents with increasing fatigue and shortness of breath over recent months. She has no significant past medical history. You find her to be pale with: Hb 6.9 g/dl (Reference range 11-13 g/dl), MCV 63fl (Reference range 78-96 fl), MCH 24 pg (Reference range 27-32pg)

1. What name is given to this blood picture? (2 marks)– Microcytic hypochromic anaemia

2. What is the most likely haematological disorder in this lady? (1 mark)– Iron deficiency anaemia

3. List two possible significant factors underlying in this patient. (2 marks)

4. What arterial PO2 would you expect? (1 mark)

5. You examine the blood report to find a reticulocyte count? What are reticulocytes? (1 mark)

6. What is the significance of a normal result? (1 mark)

7. On further questioning, you discover this patient’s ethnic background is South Asian.

8. What co-existing blood condition does this patient have? How would you test for this? (2 marks)

• A Burkitt’s Lymphoma• B Chronic Lymphoid

Leukaemia• C Chronic Myeloid Leukaemia• D Depression• E Hodgkin’s Lymphoma• F Pernicious Anaemia• G Polycythaemia Vera• H Sickle Cell Anaemia• I Sideroblastic Anaemia• J Thalassaemia

• A 65-year-old lady presents to her GP with a 3-month history of vertigo, tinnitus and visual disturbance. She admits to feeling “a bit down” and the GP decides to carry out some routine bloods. A week later she returns and you note that her blood results show a raised high haemoglobin and a raised pack cell volume and red blood cell count.

• A 12-year-old girl of Nigerian descent and with a known blood disorder presents to A&E with a two-day history of dyspnoea, cough and fever. You order several investigations and note that she has a Hb of 6g/dl (reference range 11.5 – 1.35 g/dl) and a chest X-ray showing pulmonary infiltrates.

• A Burkitt’s Lymphoma• B Chronic Lymphoid

Leukaemia• C Chronic Myeloid Leukaemia• D Depression• E Hodgkin’s Lymphoma• F Pernicious Anaemia• G Polycythaemia Vera• H Sickle Cell Anaemia• I Sideroblastic Anaemia• J Thalassaemia

• A 27-year-old man presents with a two-month history of pruritis, fatigue and weight loss. On questioning he admits that whenever he drinks alcohol, he experiences bone pain. On examination he has a rubbery non-tender submandibular lymph node. He has never had infectious mononucleosis.

• A Burkitt’s Lymphoma• B Chronic Lymphoid

Leukaemia• C Chronic Myeloid Leukaemia• D Depression• E Hodgkin’s Lymphoma• F Pernicious Anaemia• G Polycythaemia Vera• H Sickle Cell Anaemia• I Sideroblastic Anaemia• J Thalassaemia

• A 68-year-old woman presents with a history of bruising, bone pain and lymphadenopathy. Unbeknownst to the consultant, this patient has a (t9,22) mutation known as the Philadelphia Chromosome. On examination the consultant finds a massively enlarged spleen.

• A Burkitt’s Lymphoma• B Chronic Lymphoid

Leukaemia• C Chronic Myeloid Leukaemia• D Depression• E Hodgkin’s Lymphoma• F Pernicious Anaemia• G Polycythaemia Vera• H Sickle Cell Anaemia• I Sideroblastic Anaemia• J Thalassaemia

• A 37 year old lady with known hypothyroidism presents to you with fatigue, dyspnoea and palpitations. You note that she is pale and tachycardic. Routine bloods show a macrocytic anaemia. You suspect that this is caused by her hypothyroidism. You find a positive Schilling’s test.

• A Burkitt’s Lymphoma• B Chronic Lymphoid

Leukaemia• C Chronic Myeloid Leukaemia• D Depression• E Hodgkin’s Lymphoma• F Pernicious Anaemia• G Polycythaemia Vera• H Sickle Cell Anaemia• I Sideroblastic Anaemia• J Thalassaemia

QUESTIONS?