Study rebuts finding that pneumonia bacterium may cause multiple sclerosis
By Susan Gilbert
MONDAY, Jan. 10 (HealthSCOUT) -- Now there may be one less thing to worry about, especially if you're unlucky enough to get pneumonia this nasty flu season. Rebutting earlier research, a new study finds that a common cause of pneumonia doesn't promote multiple sclerosis.
Doctors from Vanderbilt University Medical Center in Tennessee made headlines at a neurology meeting last year by saying that chlamydia pneumoniae, a common bacterium that causes respiratory infections such as walking pneumonia, might also cause multiple sclerosis.
MS is an incurable, crippling nervous-system disorder whose cause is unknown. The form of chlamydia in question is different from the one that causes sexually transmitted disease.
The Vanderbilt doctors based their conclusion on two small studies. In one, chlamydia was found in the spinal fluid of 46 percent of multiple sclerosis patients, but in just 15 percent of people without the disorder. In the other, a man crippled with progressive MS was able to return to full-time work within a year after being treated with antibiotics.
But when Dr. Margaret Hammerschlag, a chlamydia expert, tried to duplicate these findings, she found no relationship between the bacteria and multiple sclerosis. Chlamydia was found in fewer of the MS patients in her study than in the control groups, she says. And the antibiotics used on the Vanderbilt multiple sclerosis patient had no effect on chlamydia, she adds.
Her report appears in the current issue of the journal Neurology.
One possible reason why the two researcher teams got opposite results is that they used different laboratory methods. "The methods that our lab used are standard," says Hammerschlag, a professor of pediatrics and medicine at the State University of New York Health Sciences Center in Brooklyn. "There are issues with the methods that they used."
Dr. Sriram Subramaniam, leader of the Vanderbilt research team, did not respond to requests for comment.
"The new study throws a monkey wrench in the hypothesis that chlamydia is involved in MS," says Dr. Stephen Reingold, vice president of research for the National Multiple Sclerosis Society. But Reingold says more research is needed before it can be said for sure that chlamydia plays no role.
"We've believed for a very long time that some infectious agent triggers
MS," Reingold says. "About 40 or 50 of them, including the measles and
influenza viruses, have generated a lot of media attention as possible
causes, but none have panned out."