The role of serum chromogranin A in diarrhoea predominant irritable bowel syndrome.

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 + or - 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.