Chlamydia pneumoniae infection associated with enhanced MRI spinal lesions in multiple sclerosis.

Cerebrospinal fluid (CSF) from 66 patients with multiple sclerosis (MS) and 25 patients with other neurological diseases (OND) were examined for the infection of Chlamydia pneumoniae by culture, polymerase chain reaction (PCR) assay, and determination of antibodies to C. pneumoniae. PCR was positive not only in 9 of 28 (32%) patients with MS but also in 2 patents with inflammatory disorders in 15 (13%) OND controls (p = 0.18). Viable C. pneumoniae was isolated from one patient with MS and one with paraneoplastic encephalomyelitis. C. pneumoniae could be detected only in cell-containing CSF. In MS, enhanced spinal magnetic resonance imaging (MRI) lesions were detected in all of four PCR-positive patents but none of five PCR-negative patients, and the difference was significant (p = 0.0079). However, no correlation was found between enhanced brain MRI lesions and CSF C. pneumoniae DNA. Elevated titers of anti-C. pneumoniae IgG were detected in CSF in 13 of 66 (20%) patients with MS and 1 of 25 (4%) OND controls (p = 0.064). CNS C. pneumoniae infection is not uncommon in MS as well as in other inflammatory disorders of the nervous system. The association of active spinal lesions with Chlamydia in CSF collected by lumber puncture suggests the detection of a recent infection. On the other hand, the lack of association of active MS brain lesions with CSF Chlamydia and the presence of PCR-positive patents who are clinically stable and have no enhancing MRI lesions imply the existence of a chronic infectious process.