Circulating amylase-linked immunoglobulin complexes found in patients with ulcerative colitis

We examined the prevalence of amylase-linked immunoglobulin complexes, known as macroamylase, in the sera of 146 patients with ulcerative colitis (UC). Six of them were found to have this complex. Combining this group with the group of 59 patients with UC examined previously in a similar fashion, provided a prevalence rate of 7 in 205 (3.4%). Of the 7 patients the binding immunoglobulin was IgG in 4, IgA in 2 and both in the remaining patient. This distribution of the immunoglobulins contrasts strikingly with a preponderance of IgA in patients with a variety of diseases. The results make definite the association between UC and circulating enzyme-linked IgG complex, and provide support for the hypothesis that autoimmune mechanisms are involved in the pathogenesis of UC.