Abstract
Thirteen sera from children with ulcerative colitis were examined for antibodies reacting with constituents of human colonic tissue by means of immunofluorescent methods. 3 out of 10 sera reacted positively when tested by the direct staining method while 6 out of 13 reacted positively when tested by the indirect method with conjugates of rabbit anti-human gamma globulin. The specificity of the reactions could be confirmed by inhibition tests. 16 sera from healthy children and adults yielded completely negative results. The staining capacity of various sera was correlated to their hemagglutinating titer when they were tested with sheep erythrocytes, coated with phenol-water extract of human colon. Absorption experiments indicated that the stainable antigen was also present in the extracts used for the hemagglutination experiments.