Case Studies
Case 14.2 Pernicious anaemia
A 67-year-old widow presented with gradually increasing tiredness, exertional dyspnoea and ankle swelling. Two years earlier she had been found to be anaemic and had been treated with oral iron without symptomatic improvement. She had lost 6kg in weight, but denied any history of anorexia, dyspepsia or blood loss. On examination, she was very pale and had signs of congestive cardiac failure.
Laboratory investigations showed a very low haemoglobin of 54g/l with a reduced white-cell count of 3.7 x 109/l (and a platelet count of only 31 x 109/l). A blood film showed marked macrocytosis with a mean cell volume of 112fl. Bone marrow examination revealed marked megaloblastic erythropoiesis with abundant iron stores. Serum vitamin B12 was 40ng/l (NR 170-900) but serum folate, serum iron and total iron-binding capacity were normal. Her serum contained strongly positive gastric parietal cell antibodies of IgG class and blocking antibodies to intrinsic factor (see below). Antibodies to thyroid microsomal antigen and thyroglobulin were also found, although the patient was clinically and biochemically euthyroid.
The patient had pernicious anaemia and was therefore started on intramuscular injections of hydroxycobalamin at 3-monthly intervals. Four days after the first injection, her reticulocyte count rose to 16%.
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