Bowel screening test could be 'important step forward'
By Lilian Anekwe
A simple screening test could be used in future as a diagnostic test for inflammatory bowel disease, after a BMJ study found it reduces the number of unnecessary endoscopic procedures.
A Dutch team of researchers found that testing the stools of people with suspected inflammatory bowel disease for calprotectin, a major protein found in the cytosol of inflammatory cells, would result in a 67% reduction in the number of adults requiring endoscopy.
A meta-analysis of 13 prospective studies of 1,000 patients found the pooled sensitivity and specificity of calprotectin was 0.93 and 0.96 in adults and 0.92 and 0.76 in children.
In a hypothetical population of 100 adults with suspected inflammatory bowel disease, three patients without the disease would go on to have endoscopy and two patients with the disease would be missed.
‘Screening by measuring faecal calprotectin levels would result in a 67% reduction in the number of adults requiring endoscopy,' the researchers wrote.
‘The downside of this screening strategy is delayed diagnosis in 6% of adults because of a false negative test result. In the population of children and teenagers, 65 instead of 100 would undergo endoscopy. Nine of them will not have inflammatory bowel disease, and diagnosis will be delayed in 8% of the affected children.'
Dr Patrick van Rheenen, paediatric gastroenterologist at the Beatrix Children's Hospital in Groningen, concluded: ‘We consider faecal calprotectin a useful screening tool for identifying those patients who are most likely to need endoscopy for inflammatory bowel disease.
‘Increased faecal calprotectin levels are less likely to be associated with intestinal inflammation and further investigations can be tailored appropriately.'
But the researchers were cautious about the utility of faecal calprotectin in primary care. In an accompanying editorial.
Dr Robert Logan, consultant gastroenterologist at Kings College Hospital, London, said: ‘If studies conducted in primary care find a high diagnostic accuracy of the faecal calprotectin test it will be an important step forward in how inflammatory bowel disease is diagnosed.'Screening test reduced the number of unnecessary endoscopies