Reaginic hypersensitivity in ulcerative colitis

Abstract

To investigate the role of reaginic mechanisms in ulcerative colitis, IgE positive and IgG4 positive cells (using immunoperoxidase staining), mast cells (using toluidine blue staining), eosinophils and tissue histamine levels (using fluorometric method with o-phthaldialdehyde) were studied. In active stage, there were significantly more IgE positive and IgG4 positive cells, and eosinophils as well as significantly elevated tissue histamine levels compared with ulcerative colitis in remission and normal controls. In active disease, mast cells were reduced in number suggesting degranulation and releasing histamine into the tissue. Following induction of remission, there was a decrease in the number of IgE positive and IgG4 positive cells, eosinophils and tissue histamine levels and an increase in the number of mast cells. These studies strongly suggested that the reaginic mechanisms were involved in recurrence and aggravation of ulcerative colitis, playing a role as an initiator of inflammation.