JC Virus Reactivation in Multiple Sclerosis

Overview

JC virus is a benign virus which infects approximately up to 90% of the normal adult population. However, it may be reactivated in people who have a decreased immune function as in HIV infection, cancer, chemotherapy, transplant recipients, or in MS patients treated with natalizumab (Tysabri). In these patients, JC virus can cause a severe brain disease called Progressive Multifocal Leukoencephalopathy (PML), for which there is no cure. As of September 2013, 400 MS patients in the world, who have been treated with natalizumab, have developed PML. The risk of PML is approximately 5 patients in 1000 after 24 months on the drug. Researchers do not know exactly in which cells of the body the virus lives but it has been isolated from the blood, urine, cerebrospinal fluid (CSF), and from the brains of patients with immunosuppression. In this study, the investigators wish to determine precisely where the virus lives, and how the body prevents it from causing brain disease. Because of the association of PML with natalizumab, the investigators would like to see if there is a difference in the amounts of virus in blood, urine, and CSF found in MS patients treated with natalizumab or those treated with different medications for MS, or those not treated at all. The investigators hope that this knowledge will allow us to find better ways of preventing the development of PML as well as treatments for patients with PML.

Subjects selected for participation in this study have been diagnosed with Multiple Sclerosis (MS). Of the MS patients enrolled in the study, some have been treated with natalizumab or a different medication for MS, and others have not been treated at all. All MS patients enrolled have their blood tested for the presence of the JC virus. Those testing negative for the JC virus do not continue in the study. Those testing positive for the JC virus continue participating in the study, and provide a urine sample, blood sample, lumbar puncture, and a neurological exam. Approximately 65 people will take part in this study at Beth Israel Deaconess Medical Center.

Conditions