Red cell distribution width as a marker of coeliac disease: a prospective study

Coeliac disease is frequently underdiagnosed because of its protean presentations. Serological tests may be helpful in screening programmes for populations at risk, but they are costly.

To determine prospectively whether a commonly available haematological test such as the red cell distribution width (RDW) could be of help in detecting unrecognized coeliac disease.

Of 353 consecutive adult patients referred to our outpatient malabsorption clinic, 198 in whom clinical suspicion was strong were referred for further investigations and intestinal biopsy. Seventy-six inflammatory bowel disease outpatients and 90 subjects admitted for diseases other than malabsorption were enrolled as the control group.

RDW was increased in 94 (47.4%) and normal in 104 (52.5%) of 198 patients. Duodenal biopsy confirmed coeliac disease in 80 (85.1%) of the former patients and 69 (66.3%) of the latter patients. No correlation between RDW values and histological scores was found. Overall RDW increase was found in 80/149 (53.7%) patients with a definite diagnosis of coeliac disease, and in 14/49 (28.6%) patients in whom biopsy excluded the disease. A 1-year gluten withdrawal led to a significant decrease in RDW value, even in patients with obdurate mucosal impairment.

In patients in whom there is a strong clinical suspicion of coeliac disease, an elevated RDW despite normal haemoglobin concentration may be a reliable predictor of the disease.