ANALYSIS OF PARAFFIN SECTIONS OF CROHNS-DISEASE FOR MYCOBACTERIUM-PARATUBERCULOSIS USING POLYMERASE CHAIN-REACTION

Although Mycobacterium paratuberculosis has been reported by both cult ure and polymerase chain reaction in unfixed intestinal tissue from pa tients with Crohn's disease, its pathologic significance is unclear. W e used polymerase chain reaction to analyze DNA for the presence of M. paratuberculosis from 27 specimens in 23 patients with Crohn's diseas e, Seventeen of these cases contained granulomata. DNA from unstained paraffin tissue sections was amplified using nested PCR specific for a 264-base pair fragment of IS900, a multicopy insertion element specif ic to M. paratuberculosis, The sensitivity of this technique was demon strated by the amplification of small numbers of cultured organisms in a paraffin cell block in the presence of large amounts of added human DNA. M. paratuberculosis was not identified in any of the specimens f rom patients with Crohn's disease, nor in any of 11 normal colon secti ons tested. Therefore, we were unable to confirm a role for M. paratub erculosis in Crohn's disease.