MYCOBACTERIUM-PARATUBERCULOSIS IN INTESTINAL TISSUE FROM PATIENTS WITH CROHNS-DISEASE DEMONSTRATED BY A NESTED PRIMER POLYMERASE CHAIN-REACTION

Background: The etiology of Crohn's disease remains unknown, but current research has concentrated on autoimmunity and/or mycobacterial infection. The polymerase chain reaction (PCR) enables the detection of genetic material even when very few microorganisms are present. Methods: A nested primer PCR for detection of a multi-copy insertional element (IS900) specific for Mycobacterium paratuberculosis was applied to DNA extracted from fresh and from paraffin-embedded intestinal tissue obtained from patients undergoing surgery. Results: In fresh intestinal tissue from 11 of 24 patients with Crohn's disease, from 2 of 10 patients with ulcerative colitis, and from 3 of 28 patients with other colonic disorders, specific M. paratuberculosis DNA was found. In paraffin-embedded Crohn's disease tissue the presence of specific M. paratuberculosis DNA was also increased. Conclusions: Whether the presence of M. paratuberculosis is connected to the inflammatory bowel disease or is a mere coincidence cannot be stated. We find this presence interesting and encouraging for further investigations.