Transmissible agents from human sarcoid and Crohn's disease tissues.

Abstract Mice were inoculated with human sarcoid tissue homogenates or with a first or a second passage homogenate of mouse tissue (including 0·2 μm membrane filtrates) originating from the inoculation of human sarcoid, Crohn's disease, or control tissue homogenates. Epithelioid and giant cell granulomas were present in the footpads and/or viscera of some of the mice given homogenates originating from each sarcoid or Crohn's disease tissue 15 months after inoculation but were not present in mice given control homogenates. Among mice given homogenates originating from human sarcoidosis, granulomas were present in many organs and tissues; in contrast, a pattern of selective dissemination of visceral granulomas was found among mice given homogenates originating from Crohn's disease. This differential distribution of visceral granulomas also followed the inoculation of 0·2 μm membrane filtrates. Granulomatous responses at Kveim test sites in the ear 9-17 months after inoculation of homogenates originating from human sarcoidosis or Crohn's disease were confined to mice showing granulomas in footpads or viscera. The ability of the transmissible agents to induce granulomas in mice was destroyed when sarcoid or Crohn's tissues were autoclaved or when sarcoid homogenates were stored at -20°C for 1 week or exposed to 60 Co irradiation (2·5 MR).