The haemoglobin reference range will vary depending on the age, gender and pregnancy status of the patient, as well as the laboratory performing the test. In general, the haemoglobin is considered to be low when it is < 130 g/L in males and <115 g/L in females. The MCV and reticulocyte count are useful to guide further investigation as below.
The easiest approach to anaemia is to look at the mean cell volume (MCV) which normally sits between 80-100fL although may vary between labs.
Microcytic anaemia (usually MCV < 80 fL)
- Iron deficiency - low ferritin clinches the diagnosis
- Haemoglobinophaties - thalassaemia - Hb electrophoresis, HPLC, capillary electrophoresis
- Anaemia of chronic disease - usually at later stages, high hepcidin and functional iron deficiency
Macrocytic anaemia (MCV > 100fL)
- High reticulocyte count
- Haemorrhage
- Haemolysis
- Low-Normal reticulocyte count
- B12, folate deficiency
- Myelodysplasia
- Drugs - antimetabolites - Hydroxyurea, Azathioprine
- Chronic liver disease
- Alcoholism
Normocytic anaemia
- Anaemia of chronic disease
- Anaemia of chronic renal failure
- Marrow infiltration - frequently accompanied by other cytopenias
- haematological or non-haematological metastatic disease
- non-malignant process
- Aplastic anaemia
Initial tests
- Reticulocyte count
- Peripheral blood film review
- Iron studies
- B12 and folate
- Haemolytic screen
- Serum protein electrophoresis and serum free light chain assay
- ELFT
Management
If no cause is identified with thorough investigation, mild anaemia (Hb >100g/L) without other cytopenias can be safely monitored
When To Refer
Symptoms
- Unxplained fevers > 38° C
- Unintentional weight loss
- Drenching night sweats
Physical examination
- Hepatosplenomegaly
- Lymphadenopathy
Laboratory
- Anaemia (Hb < 100g/L)
- Thrombocytopenia (PLT<100x109/L)
- Neutropenia (ANC< 1 x 109/L)
- Immature cells on peripheral blood film
- Dysplastic features on peripheral blood film