A new study has identified and “immune exchange” that allows disease-causing cells in patients with multiple sclerosis to move in and out of the brain. Researchers state that this exchange may be the key to better treatments and diagnostics in the future.

According to the study’s authors, one current theory on multiple sclerosis holds that self-reactive B cells in the brain activate and cause inflammation. The exchange of B cells uncovered by the new study could mean that the B cells are “accessible” when moving from the brain.

“The hope is that if we can identify culprit B cells, using precise tools, we will be able to better diagnose multiple sclerosis and monitor disease activity,” said Dr. Hans Christian von Büdingen, lead author of the study and neurologist at the University of California at San Francisco (UCSF). “In addition, in ways that may have to be tailored for each patient, this may also allow us to develop therapies that directly target disease-causing B cells.”

The study, published this week in the Journal of Clinical Investigation, obtained DNA sequences from multiple sclerosis patients at the UCSF Medical Center. Since 2008, two UCSF clinical trials have shown that blocking B cells may stop multiple sclerosis flare-ups from occurring. Büdingen and his colleagues hope their new findings will lead to a “precision strategy” where treatments can be tailored to the exact identity of the culprit B cells in a particular patient.