The role of mycobacteria in the pathogenesis of sarcoidosis.

The pathogenesis of sarcoidosis has intrigued clinicians since the first descriptions of the disease, and a number of causes have been proposed. Among the candidate agents, the possible role of mycobacterial infection in the pathogenesis of sarcoidosis has attracted by far the most attention. The purpose of this review is to summarize current evidence concerning the role of mycobacterial infection in sarcoidosis. First, the similarities in clinical and histological features of tuberculosis and sarcoidosis that have raised suspicion that mycobacterial infection could be involved in the pathogenesis of sarcoidosis are discussed. In addition, experimental evidence for and against a role of mycobacterial infection is summarized, including recent attempts to detect mycobacterial DNA in clinical samples from patients with sarcoidosis by polymerase chain reaction.