The Role of Serum Chromogranin A in Diarrhoea Predominant Irritable Bowel Syndrome

Abstract

Background & Aims: Elevated serum chromogranin A (CgA) levels have been reported co-incidentally in a small group of irritable bowel syndrome (IBS) patients (n=19). Our aim was to ascertain the prevalence of elevated CgA in diarrhoea predominant Rome II IBS (D-IBS) patients and investigate if this could be a marker for octreotide therapy.

Methods: Patients with Rome II D-IBS were recruited prospectively and investigated as per British Society Guidelines including serial CgA levels (u/l). Patients with refractory symptoms and elevated CgA were considered for further investigation +/- octreotide therapy.

Results:  219 patients were recruited (68% females, mean age 45 years). 81% (n=177) of IBS patients had normal CgA levels (0-20u/l). Whilst 12.3% (n=27) had values between 20-60u/l, 6.8% (n=15) had CgA levels >60u/l; 96% (26/27) with initial CgA level of 20-60u/l had repeated CgA levels which normalised. One patient (3.7%) had a gastric adenocarcinoma. In the 15 patients with elevated CgA levels >60u/l, 8 normalised on repeated testing. In the other 7, there were no cases of carcinoid, n=1 gastric leiomyoma, n=1 rectal tumour and 4 patients had persistently elevated CgA levels but with improvement of symptoms. In one patient, octreotide was commenced which resulted in normalisation of CgA and symptoms.

Conclusion: CgA levels appear to be transiently elevated in D-IBS. Future work assessing CgA in patients with refractory D-IBS may potentially identify individuals who will benefit from octreotide therapy.