What is not clear is whether C. pneumonia is the cause of MS, a fortuitous bystander, or whether it in some way triggers an autoimmune response which causes the disease. The cause of MS is not known. In MS, the insulating material of the nerves, myelin, is destroyed. This leads to problems in vision, balance, gait, and other neurologic functions. Current theories suggest that a poorly regulated immune response against common infectious agents may be responsible for the disease.
Chlamydial species are well-known pathogens involved in a number of human diseases.
Chlamydia pneumonia was discovered about 10 years ago and is now thought to be responsible for many cases of community-acquired pneumonia. The association between C. pneumonia and MS has not been previously noted. In a study of 17 patients with newly diagnosed relapsing remitting MS and 13 patients without the disease, researchers found evidence of the chlamydia pneumonia organism in the spinal fluid of all 17 MS patients. In 47 percent of newly diagnosed MS patients, the organism was directly cultured from cerebrospinal fluid. Using sophisticated genetic tests, researchers found the DNA of chlamydia pneumonia in the cerebrospinal fluid of all the MS patients.