27 - Markers of malabsorption: coeliac disease

Summary

Introduction

Coeliac disease, or gluten-sensitive enteropathy, is an inflammatory condition that affects mainly the small intestine, resulting in loss of the normal villous architecture. The lesion returns towards normal with a gluten-free diet – that is, the complete avoidance of wheat, rye, barley and possibly oats. In dermatitis herpetiformis, the skin is the organ primarily affected, although some degree of enteropathy is almost always present.

Classically, gluten-sensitive enteropathy consists of a flat small intestinal mucosa, whose greatly reduced surface area results in malabsorption, leading to gross steatorrhoea and multiple loss of nutrients. It is now recognized that there is a spectrum of lesions, some of which are very subtle. The patient may be asymptomatic (silent coeliac disease) or may suffer from deficiency of a single nutrient in the absence of any gastrointestinal symptoms. Thus, unexplained anaemia in a man, or osteoporosis in a premenopausal woman, for example, should set the alarm bells ringing.

Prior to the advent of serological tests or small bowel biopsy, diagnosis had to be made on the basis of measurement of faecal fat. This nonspecific marker indicates only the presence and not the cause of fat malabsorption, which might originate from pancreatic insufficiency among a number of causes. It is now known that many gluten-sensitive individuals have normal fat absorption.