ANSWER 54
The most likely diagnosis is malabsorption from coeliac disease.The report of a dimorphic
blood film means that there are both small and large cells. This suggests that the anaemia
is caused by a combination of the folate deficiency indicated by the red cell folate and by
iron deficiency. The Howell–Jolly bodies are dark blue regular inclusions in the red cells
which are typically found in the blood of patients after splenectomy, or are associated with
the splenic atrophy which is characteristic of coeliac disease. In coeliac disease, there is a
sensitivity to dietary gluten, a water-insoluble protein found in many cereals. The proximal
small bowel is the main site involved with loss of villi and an inflammatory infiltrate caus-
ing reduced absorption.
The MCV is at the upper limit of normal.
- Folate deficiency
- Vitamin B 12 deficiency
- Excessive alcohol consumption
- Hypothyroidism
- Certain drugs, e.g. azathioprine, methotrexate
- Primary acquired sideroblastic anaemia and myelodysplastic syndromes
! Causes of macrocytosis in the blood film
Coeliac disease is made more likely by a possible positive family history and the origin
from Ireland where coeliac disease is four times as common as in the rest of the UK. Other
diagnoses which might be considered are anorexia nervosa (her age and sex, commitment
to exercise); she does not appear depressed (a common cause of weight loss and bowel dis-
turbance) and the laboratory findings clearly indicate physical disease.
Diagnosis of coeliac disease can be confirmed by endoscopy at which a biopsy can be taken
from the distal duodenum. Typically this will show complete villus atrophy. Antigliadin
antibodies are usually positive and can be a useful screening test. The treatment is a gluten-
free diet with a repeat of the biopsy some months later to show improvement in the height
of the villi in the small bowel. In some cases, temporary treatment with steroids may be
needed to help recovery. Another common cause of failure to recover the villus architec-
ture is poor compliance to the difficult dietary constraints.
- Howell–Jolly bodies are characteristic of hyposplenism.
- Coeliac disease can present at any age with non-specific symptoms; absence of abdom-
inal pain and/or steatorrhoea are not unusual. - Typical features of fat malabsorption may not be evident if the patient eats a diet with
little or no fat intake.