Invasive or non-invasive methods for the diagnosis of subclinical coeliac disease?

LETTERS Invasive or non-invasive methods for the diagnosis of subclinical coeliac disease? I read with great interest the letters published in Gut on the role of small bowel biopsies and antiendomysial antibodies (EMA) as methods for diagnosing coeliac disease in patients with iron deficiency anaemia (IDA) (Gut 2001;49:595). In particular, Pearce et al seem to prefer EMA instead of histological evaluation because of the considerable resource implications for histology departments, and Scott seems to agree with Pearce's affirmation even if he takes into consideration the important role of histological evaluation. However, I do not completely agree with the conclusions of these authors. Firstly, I would debate the role of non-invasive methods in diagnosing subclinical/ silent coeliac disease. In my experience, IDA is the main indication of subclinical forms of coeliac disease 1 and thus it should be taken into consideration in clinical practice. Although EMA are a well known hallmark of coeliac disease and the prevalence is more than 90% in classical forms of coeliac disease, our study and other recent studies clearly showed that the prevalence of EMA (as well as AGA) is lower than expected in clinical practice, 2–4 probably due to the high prevalence of slight histological lesions in these patients (Marsh I-IIIa lesions according to the Marsh classification 5). In contrast, the sorbitol H2-breath test (H2-BT) seems to be more effective than EMA in diagnosing this form of coeliac disease, probably because of a better correlation with slight histological lesions. 6 In the light of these experiences, sorbitol H2-BT may be a good alternative to small bowel biopsy in identifying coeliac disease in patients with IDA but unfortunately this is not always true. In fact, in clinical practice, it is easy to observe patients with IDA EMA− and a negative sorbitol H2-BT test who show slight histological lesions (Marsh I-II type lesions) with disappearance of IDA and improvement in histology after a gluten free diet (GFD). In these cases the use of non-invasive methods (such as EMA) may be a serious mistake as we may run the risk of not identifying hidden coeliac disease. These experiences are very important and should be considered in the cost/benefit ratio of diagnosing coeliac disease. Other important points are the patchiness of the disease, difficulties for pathologists in obtaining biopsies orientated sufficiently, and the cost of small bowel biopsy. Pearce et al are not in favour of biopsy. Firstly, many …