J Clin Immunol. 2000 Jan;20(1):68-76.  

Distal proctocolitis and n-3 polyunsaturated fatty acids (n-3 PUFAs): the

mucosal effect in situ.

Almallah YZ, Ewen SW, El-Tahir A, Mowat NA, Brunt PW, Sinclair TS, Heys SD,

Eremin O.

Department of Surgery, University of Aberdeen, United Kingdom.

yzalmallah@rcsed.ac.uk

It has been postulated that patients with ulcerative colitis (UC) have altered

reactivity of gut-associated lymphoid tissue. In such cases there is intense

infiltration of the mucosa with immune competent cells and associated tissue

damage. We have shown previously that the dietary supplementation with 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) daily 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 rectal biopsy specimens (before and

after six months supplementation) using monoclonal 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) and HLA-DR and IgM containing cells compared

with non-colitic controls (n = 8). Six months supplementation with n-3 PUFAs

resulted in significant reduction in the number of cells expressing CD3 and HLA

and the percentage of cells containing IgM. There was no significant change in

the CD20 nor the percentage of IgG or IgA containing cells in either group of

patients with procto-colitis. In patients receiving n-3 PUFA supplementation,

there was improvement in the disease activity and histological scores, compared

with pretreatment evaluation. This study has demonstrated both evidence of

suppression of in situ immune reactivity and concurrent reduction in disease

activity in patients with proctocolitis receiving n-3 PUFA supplementation. This

may have important implication for therapy in patients with ulcerative colitis.