Nutritional Anaemias

Question 1

Definition of nutritional anaemias, causes and WHO recommendations, treatment

Answer 1

• deficiency in size and number of erythrocytes or amount of Hb limiting exchange of O2 and CO2 between cells
• causes: prolonged Negative Fe balance, inadequate dietary intake
• causes lethargy, decreased productivity, wellbeing and work performance
• WHO aiming to reduce anaemia by 50% in women of childbearing age. Want to restore Hb levels by encouraging dietary diversity and food supplementation, to enhance economic growth
• treatment: red blood cell transfusion, oral Fe therapy

Question 2

Initial investigations for nutritional anaemias

Answer 2

• clinical signs: eating clay, ice, conjunctival pallor, chest pain, shortness of breath
• biochemical: haematocrit (% of blood volume and RBC), haemoglobin, mean corpuscular volume (avg size of RBC), mean corpuscular haemoglobin (avg Hb content of RBC), RDW (range of deviation around the average size of RBC)

Question 3

Classifications of nutritional anaemias

Answer 3

1) microcytic: (<80 fL) hypochromic (low Hb), Fe deficiency
2) macrocytic: (>100 fL) normochromic (normal Hb), vitamin B12 or folate deficiency
3) normocytic (80-100 fL): normal MCV, haemolytic, low RBC

Question 4

Stimulation of erythropoiesis

Answer 4

• erythropoietin is produced by the kidneys in response to low O2
• erythropoiesis takes 5 days and is dependent on B12, folate, vitamin A, C, E, riboflavin and B6

Question 5

Iron homeostasis

Answer 5

• absorb 1-2 mg per day and 1-2 mg is lost
• plasma turnover is 20-25 mg/day
• Hepcidin produced by the liver and blocks ferroportin channels and blocks Fe absorption
• Fe from senescent RBC is recycled using spleen macrophages
• absorption of Fe would be greater if deficient

Question 6

Folate deficiency: causes, symptoms, diagnosis, treatment

Answer 6

• causes: alcoholics and MTX users (blocks absorption), teens with poor diet, increased requirements during pregnancy
• clinical features: diarrhoea, glossitis (red tongue), cheilosis (cracks in corners)
• diagnosis: blood smear, would have high homocysteine but low MMA
• treatment: oral replacement therapy (prophylactic in pregnancy)
• macrocytic anaemia

Question 7

Vitamin B12: features, diagnosis, treatment

Answer 7

• features: neurological (in 75%), glossitis, diarrhoea, macrocytic anaemia
• diagnosis: schilling test (see if deficient in intrinsic factor), MMA blood test, urinary FIGLU
• treatment: oral replacement, IM injection

Question 8

Haemolytic anaemia definition and causes

Answer 8

• excessive haemolysis leading to low RBC count
• can be caused by vitamin C, E, selenium deficiency
• may be non-nutritional and form from genetic disease i.e favism (G6PD)

Question 9

Sickle cell disease: definition, main clinical features, treatment

Answer 9

• group of disorders which affect Hb. Autosomal recessive. Type: HbSS (most severe), HbSC, HbSC (+) thalessemia, HbSB (0) thalessemia
• clinical features: chronic haemolysis, vasoocculsion, chronic inflammation, impaired immune function
• treatment: aim is to limit sickle cell crisis. Using disease modifying drugs. Can use hydroxycarbamide (anti cancer) to prevent sickle cell crisis. Can use blood transfusions and iron chelation therapy

Question 10

Thalessemia definition, clinical features, treatment

Answer 10

• definition: haemoglobinopathy. Types are alpha, beta, major and minor. Severity depends on lack of globin genes
• diagnosed via blood testing
• clinical features: pale skin, fatigue, bone problems, jaundice, enlarged spleen
• treatment: severe disease requires regular blood transfusions, iron chelation and folate