Chlamydia pneumoniae and multiple sclerosis: no significant association.

The cause of multiple sclerosis (MS) is unknown. Despite indications from epidemiological and identical-twin studies that MS is infectious, no virus or other infectious agent has been tightly linked to disease. The isolation of Chlamydia pneumoniae from the cerebrospinal fluid (CSF) of MS patients and the detection of both Chlamydia-specific DNA and antibody in MS CSF have been reported. Other analyses of brain and CSF have shown no significant difference in C. pneumoniae-specific DNA or antibody between MS and control subjects. Recent work has revealed intrathecal production of C. pneumoniae-specific IgG in only 24% of MS patients compared with 5% of control patients. More importantly, the major CSF oligoclonal bands from MS patients did not react to C. pneumoniae.