A 34-year-old woman with a 3-month history of loose stools, bloating, and fatigue has iron-deficiency anaemia; tissue transglutaminase antibodies are significantly elevated and she awaits endoscopic biopsy. Which of the following would be the most appropriate initial advice?

A 34-year-old woman with a 3-month history of loose stools, bloating, and fatigue has iron-deficiency anaemia; tissue transglutaminase antibodies are significantly elevated and she awaits endoscopic biopsy. Which of the following would be the most appropriate initial advice?

• A. Start iron supplementation
• B. Gluten-free diet
• C. Coeliac dietary advice
• D. Endoscopy immediately

Answer: (C)

The key idea is to preserve diagnostic accuracy for suspected coeliac disease. Positive tissue transglutaminase antibodies strongly suggest coeliac disease, but the diagnosis is still confirmed by duodenal biopsy. A gluten-containing diet must be maintained until this biopsy is performed because removing gluten prior to histology can reduce or reverse villous damage, leading to a false-negative biopsy and making the diagnosis harder to confirm later. So the most appropriate initial step is to advise continuing a normal gluten-containing diet (and plan the endoscopy with biopsy as scheduled). Iron supplementation may help the anemia, but it doesn’t address the need to obtain an accurate biopsy. Starting a gluten-free diet before biopsy would compromise diagnostic yield, and rushing to endoscopy immediately isn’t necessary beyond the planned procedure. In short, keep the patient on a normal diet containing gluten to ensure the biopsy accurately reflects the mucosal state, while addressing iron deficiency and proceeding with the diagnostic endoscopy.

The key idea is to preserve diagnostic accuracy for suspected coeliac disease. Positive tissue transglutaminase antibodies strongly suggest coeliac disease, but the diagnosis is still confirmed by duodenal biopsy. A gluten-containing diet must be maintained until this biopsy is performed because removing gluten prior to histology can reduce or reverse villous damage, leading to a false-negative biopsy and making the diagnosis harder to confirm later.

So the most appropriate initial step is to advise continuing a normal gluten-containing diet (and plan the endoscopy with biopsy as scheduled). Iron supplementation may help the anemia, but it doesn’t address the need to obtain an accurate biopsy. Starting a gluten-free diet before biopsy would compromise diagnostic yield, and rushing to endoscopy immediately isn’t necessary beyond the planned procedure.

In short, keep the patient on a normal diet containing gluten to ensure the biopsy accurately reflects the mucosal state, while addressing iron deficiency and proceeding with the diagnostic endoscopy.