ATP Expression in Lymphocytes of MS Patients by Means of "ImmuKnow®" Assay.

The purpose of this study is to see if we can find a new way to test how certain Multiple Sclerosis (MS) medications work in the body and to better understand how the medicines change certain substances (cells) found in the immune (protective) system. Blood test will be drawn by doing the following: * Use a new method called the "Immuknow®" Test to see if this method will help to better understand how MS medicines work. * Measure certain levels of immune cells in a new way, to see if it this will help to understand the body's response to MS medicines. These methods will test those with MS who are not taking any MS medications, to help us compare the results. About 100 subjects will be enrolled in this study at the Partners Multiple Sclerosis Center at Brigham and Women's Hospital. Biogen Idec, Inc. of Cambridge, MA, is paying for this study to be done.