Identifiering av mastceller och vasoaktiv intestinal polypeptid och deras association till irritable bowel syndrome

Sammanfattning: IBS (irritable bowel syndrome) is a functional gastrointestinal disorder which is estimated to affect one in ten individuals. It affects bowel function and leads to discomfort and pain for the patient. IBS can be subdivided into three separate groups named after the symptoms they bring: IBS-C (constipation), IBS-D (diarrhea) and IBS-M (mix). Today, there are no diagnostic markers for the disorder. The small and large intestine are regularly exposed to foreign substances and microorganisms; hence they contain a large number of immune cells of all sorts. Mastcells (MC) are pro-inflammatory cells and can be found in vast numbers in the intestine wall. They are thought to play an important role in the development of IBS. Studies has also shown that the neuropeptide vasoactive intestinal polypeptide (VIP) alter the function of the intestine and increased amount of VIP have been detected in plasma from IBS-patients. The purpose of this study was to compare the number of MCs and MCs containing VIP in colonic biopsies from: 6 healthy women, 6 women with IBS-D and 6 women with IBS-C. VIP in plasma was also measured in order to compare the amount between healthy and IBS-patients. MCs and VIP containing MCs were quantified using immunohistochemical techniques where the colonic tissue was double stained with antibodies directed towards mast cell tryptase and VIP. Evaluation of the immunostained tissue was performed using fluorescent microscopy. VIP in plasma was analysed using enzyme immunoassay (EIA). No significant difference in the number of MCs nor in MCs containing VIP was detected between the groups. However, significant differences in the amount of VIP in plasma was detected between healthy women and women with IBS-D. More studies are needed to elucidate the role of MC and VIP in the pathogenesis of IBS.