A study of Crohn's syndrome using tissue extracts and the Kveim and Mantoux tests.

Fifty patients with Crohn's syndrome and 20 with ulcerative colitis were investigated in an attempt to assess the possible antigenic activity of Crohn's tissue extracts as determined by skin testing and precipitin reactions; the response to Kveim testing in Crohn's syndrome; the Mantoux state in Crohn's cases compared with that in ulcerative colitis; the correlation between the Mantoux state with (a) the histological type of Crohn's syndrome and (b) with the severity of inflammation in ulcerative colitis. I suggested in 1963 that skin testing with extracts of Crohn's tissue might be worthwhile on the analogy of the Kveim test in sarcoidosis. The histology of Crohn's tissue may be subdivided into two main groups, with and without focal (sarcoid-like) granuloma (Williams, 1964). On this analogy the Crohn's extracts were prepared from tissue showing focal granuloma and the tests were only made on patients with negative Mantoux reactions.