Small-bowel abnormalities in multiple sclerosis.

Jejunal biopsies were performed in 12 randomly chosen patients with multiple sclerosis. The jejunal mucosa was examined histologically, ultrastructurally, and by tissue immune techniques. Histology showed a normal mucosa in 7 patients, increased inflammatory-cell infiltration in 3, a partial villous atrophy in 1, and a subtotal villous atrophy in the remaining patient. Fine structural abnormalities were seen in 6 of 8 patients studied. These included microvillous changes, increase in theliolymphocytes and epithelial lysosomes, thickening of the connective tissue with or without collagen fibres, and numerous macrophages containing large amounts of membrane-bound electron-dense material. The latter was seen in 5 of the 8 mucosae examined.