Immunological studies in ulcerative colitis. VII. Anti-colon antibodies of different immunoglobulin classes.

Ten out of sixty-three sera from patients with ulcerative colitis gave positive staining of goblet cells in the indirect immunofluorescence test, applied to acetone–ethanol fixed sections of colon from germ-free rats. Nine of these sera were also positive in triple layer tests in which the second layer consisted of rabbit antibodies to human immunoglobulin chains and the third layer of fluorescein conjugated sheep anti-rabbit immunoglobulin. All sera contained anti-colon antibodies having light chains of both κ- and λ-type. Heavy chains of both γ-, μ- and α-type occurred at almost equal frequency and only three of the nine positive sera contained antibodies of a single immunoglobulin class. One out of four tested sera which contained antibody of the IgA-class also gave positive reactions for secretory-piece determinants. The staining pattern obtained with antibodies of different classes was similar. Anti-colon antibodies belonging to the IgD or IgE classes were not detected. The triple layer test was negative when the patients' sera were replaced by normal human sera.