A 72-year-old male has presented acutely unwell to the Emergency Department and found to be in acute renal failure. You have been asked to review him.

His Full Blood Count report is as follows:

Test

Value

Normal Adult Range

White Cell Count

6.45 x 109/L

4.0 – 11.0

Haemoglobin*

97 g/L

130 – 180

Platelets

181 x 109/L

150 – 400

Haematocrit*

0.282

0.40 – 0.54

Mean Corpuscular

Volume*

101.1 fL

79 – 99

Red Cell Count*

2.79 x 1012/L

4.5 – 6.5

Mean Corpuscular

Haemoglobin*

34.8 pg

27 – 34

Mean Corpuscular 
Haemoglobin Concentration

344 g/L

320 – 360

Red Cell Distribution 

Width – Standard

Deviation

53.2 fL

Red Cell Distribution

Width – Coefficient

Variation

14.4%

10.0 – 17.0

Neutrophils %

64.1%

  • List four possible causes of this blood picture.
  • List four possible blood tests specific to aiding diagnosis in this case.

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College Answer

a)

  • Alcohol abuse
  • Liver disease
  • Haemolysis
  • Haemorrhage
  • Folate deficiency
  • Vitamin B12 deficiency
  • Exposure to chemotherapy or other drugs
  • Myelodysplasia
  • Hypothyroidism

b)

  • Reticulocyte count
  • Serum B12
  • Serum + red cell folate
  • Serum EPG Immunoglobulins
  • LFT
  • Thyroid function tests
  • Haptoglobins
  • LDH

Discussion

This is macrocytic hypochromic anaemia.

One can find the many causes of macrocytosis in this article.

  • Drugs:
    • trimethoprim, triamterine, nitrous oxide, phenytoin, valproate, chemotherapy agents, HIV antiretrovirals and metformin.
  • Alcoholism
  • Reticulocytosis
  • Nonalcoholic and alcoholic liver disease
  • Hypothyroidism
  • Vitamin B12 deficiency
  • Folate deficiency
  • Multiple myeloma
  • Myelodysplastic syndromes
  • Aplastic anemia
  • Acute leukemia

Four tests to rule them all?

  • TFTs
  • LFTs
  • B12 levels
  • Folate levels

The college also throws in several other tests, eg. a reticulocyte count and haptoglobin. If one is considering myelodysplasia or B12/folate deficiency, then one might also consider a blood film. Classic morphological features (anisocytosis and poikilocytosis) would be seen in the former. The latter is more characterised by dysplasia of red and white cells with spared platelets. If we are going on this tangent, then one might view a bone marrow biopsy as the ultimate gold standard, but the college did ask for blood tests specifically.

References

References

Aslinia, Florence, Joseph J. Mazza, and Steven H. Yale. "Megaloblastic anemia and other causes of macrocytosis." Clinical medicine & research 4.3 (2006): 236-241.