Bacteriological investigation on biopsy specimens from patients with sarcoidosis.

Biopsy specimens, mostly lymph nodes, removed under aseptic conditions, were emulsified and the homogenate was inoculated in various media, which were incubated aerobically or anaerobically. Only Propionibacterium acnes was isolated in high incidence and the highest concentration of bacteria was 6.5 X 10(5) per g tissue: 28 and 31 out of 40 lymph nodes were positive on solid and on liquid media, respectively. P.acnes was also isolated from control non-sarcoidosis lymph nodes: 4 and 8 out of 14 were positive on solid and on liquid media, respectively. The highest concentration of bacteria was 1 X 10(4). A bacterial component derived from P. acnes was used for the passive hemagglutination test to estimate antibodies against the bacterium and also for skin test on patients. These results showed only slight differences between patients with sarcoidosis and control patients. No other bacteria or fungi were isolated.