Distal proctocolitis and n-3 polyunsaturated fatty acids (n-3 PUFAs): The mucosal effect in situ

It has been postulated that patients with ulcerative colitis (UC) have alte red reactivity of gut-associated lymphoid tissue. In such cases there is in tense infiltration of the mucosa with immune competent cells and associated tissue damage. We have shown previously that the dietary supplementation w ith the n-3 polyunsaturated fatty acids (n-3 PUFAs), eicosapentaenoic acid; EPA), and docosahexaenoic acid (DHA) results in significant systemic immune suppression. The aim of this study, therefore, was to evaluate the in situ effect of n-3 PUFAs on distal proctocolitis. Each patient received either fish oil extract (EPA 3.2 g, DHA 2.4 g) (n = 9) or sunflower oil (n = 9) da ily in a double blind manner for six months. Monthly assessment included: ( 1) disease activity using clinical, sigmoidoscopic, and histological scores and (2) immunohistochemical analysis (immunoglobulins, CD profiles) of rec tal biopsy specimens (before and after six months supplementation) using mo noclonal antibodies and quantitative computer-assisted video image analysis . Prior to receiving supplementation, patients with proctocolitis (n = 18) Showed significantly higher numbers of cells expressing CD3 (pan T cells) a nd HLA-DR and IgM containing cells compared with non-colitic controls (II = 8). Six months supplementation with n-3 PUFAs resulted in significant redu ction in the number of cells expressing CD3 and HLA and the percentage of c ells containing IgM. There was no significant change in the CD20 nor the pe rcentage of IgG or IgA containing cells in either group of patients with pr octo-colitis. In patients receiving n-3 PUFA supplementation, there was imp rovement in the disease activity and histological scores, compared with pre treatment evaluation. This study has demonstrated both evidence of suppress ion of in situ immune reactivity and concurrent reduction in disease activi ty in patients with proctocolitis receiving n-3 PUFA supplementation. This may have important implication for therapy in patients with ulcerative coli tis.