April 3, 2003
By Jill Stein
Chlamydia pneumoniae infections are associated with an increased risk for exacerbations in patients with relapsing-remitting multiple sclerosis (MS), investigators reported here at the 55th Annual Meeting of the American Academy of Neurology.
Dr. Rogier Q. Hintzen and colleagues at Erasmus University. Rotterdam, the Netherlands, conducted a prospective follow-up of 73 patients with the relapsing-remitting form of MS. The mean length of follow-up was 1.7 years.
Patients were seen every 8 weeks, and an additional two visits 3 weeks apart were scheduled in the event of an exacerbation or clinically evident infection.
The Expanded Disability Status Scale (EDSS) was evaluated at each visit, and blood was collected.
Overall, 1,001 sera were tested by ELISA for anti-C. pneumoniae immunoglobulin G (IgG), -A, or -M. Control antibodies were assessed against Chlamydia trachomatis, Mycoplasma pneumoniae, and anti-staphylolysine.
At a total follow-up of 6,466 weeks, 17 of 73 patients had at least one episode in which a significant titre increase of IgG, -A, or -M against C. pneumoniae occurred. Of these 17 patients, C. pneumoniae serology was positive during 442 of 1,633 weeks of follow-up. During these seropositive weeks, the risk rate ratio for exacerbation was 2.3 (P=0.015) compared with the seronegative weeks in the same patients.
Control antibodies were not increased during the C. pneumoniae seropositive episodes.
In addition, PCR was positive for C. pneumoniae in nine of 12 nasopharyngeal swabs of the C. pneumoniae seropositive patients compared with only one in 10 swabs of the C. pneumoniae-negative patients.
Results show that transient serologically defined C. pneumoniae infections occur with the same frequency in relapsing-remitting MS patients as has been reported for the healthy population in other investigations. In MS patients, these periods of C. pneumoniae infections are associated with an increased risk of flare-ups.
Dr. Hintzen said that the investigation is the first to examine the effect of C. pneumoniae infections on MS disease activity.
The study was supported by Erasmus MC, Preventiefonds, and the Dutch MS Foundation.
[Study title: Chlamydia Pneumoniae Infections Are Associated with Increased
Disease Activity in Multiple Sclerosis. Abstract: P01.119]
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