Multiple Sclerosis Drug May Change Immune Cells

A recent study discovered that changes in immune cells may be linked to relapses in patients with multiple sclerosis who take the drug Gilenya (fingolimod).

In multiple sclerosis, T cells enter the brain and react with the myelin coating on neurons. Before this occurs, T cells must migrate to the brain. Currently, Gilenya and Tysabri are the only approved treatments that prevent the migration of T cells.

Gilenya prevents T cells from moving from secondary lymphoid organs, and decreases the number of central memory T cells. This drug has also demonstrated the ability to reduce relapses.

However, some studies have indicated that the drug may not lower the amount of central memory cells in the periphery blood, and is linked to relapses.

The current study, published by Scientific Reports, examined T cells in blood samples from patients with multiple sclerosis treated with Gilenya, both in remission and relapse. These findings were then compared with blood samples from healthy patients and patients with multiple sclerosis who have not been treated with Gilenya.

Included in the study were 33 patients with relapsing-remitting multiple sclerosis, and 10 control patients. Of the 16 patients receiving Gilenya, 11 did not experience relapses, but 5 did.

Patients were considered to be in remission if they were clinically stable for longer than 30 days. Relapse was defined as the period within 14 days after a flare, with neurological episodes occurring longer than 24 hours.

During blood analysis, investigators found that T cell composition changed in patients treated with Gilenya, with significantly increased changes observed during relapse. This finding was not present in any other group, according to the study.

Patients receiving Gilenya had increased levels of CD56+-expressing T cells, that are linked to multiple sclerosis pathology. These T cells increased even further during relapse.

They also discovered that central memory T cell levels were lower in patients treated with Gilenya who relapsed compared with those who were relapse-free. This indicated that the level of central memory T cell reduction cannot explain relapse in these patients, according to the study.

Interestingly, the investigators found that 1 patient’s levels of CD56+-expressing T cells increased 6 months prior to relapse, and relapse-experienced patients taking Gilenya had high levels of these T cells during remission.

These findings suggest that the frequency of CD56+-expressing T cells could be a used as a biomarker to predict relapses.

The investigators said that Gilenya may put the patients with multiple sclerosis in different immune situations, even though the drug does not directly cause an increased expression of these cells that seems to cause disease progression.

Additional studies are needed to determine the role of these T cells in patients with multiple sclerosis being treated with Gilenya, the study concluded.