A 22-year old woman complains of tiredness, abdominal pain and intermittent diarrhoea with a 10-kg weight loss over a period of 6 months. She is pale and has an itchy vesicular rash on her elbows and knees. Her most recent blood results are as follows:
Haemoglobin 9.0 g/dl (11.5 – 15.5 g/dl)
MCV69 fl (76-98 fl)
Albumin 21 g/l (35-55 g/l)
Free T4 15 (11-22 pmol/l)
TSH 4.0 μu/l (0.17-3.2 μu/l)
What is the single most initial test to diagnose this condition ?
A)Tissue Transglutaminase (TTG) antibodies – IgA
B )Endomysial Antibody IgA
C) Duodenal Biopsy
D) Jejunal Biopsy