Progressive Multifocal Leukoencephalopathy (PML) is an infectious, demyelinating disease of the central nervous system, which occurs in immunosuppressed individuals with AIDS, leukemia, or in organ transplant recipients. PML has also been reported in patients with inflammatory or auto-immune diseases treated with immunomodulatory medications. PML is caused by a reactivation of the polyomavirus JC (JCV), which destroys oligodendrocytes, the myelin-producing cells in the brain. JCV is a benign virus, which infects the majority of healthy individuals without causing any disease.
The goal of these NIH-sponsored, IRB-approved studies is to characterize the immunological, virological and radiological prognostic factors of disease evolution. HIV-positive or HIV-negative immunosuppressed individuals will qualify for these studies if they have neurological symptoms and brain lesions suggestive of PML, or if they have a positive brain biopsy or detectable JCV DNA in their cerebrospinal fluid.
Clinical studies are conducted in conjunction with the basic research laboratories within Division of Neuro-Virology. To learn more the Division of Neuro-Virology and its basic research work, please click
Title: Cellular Localization and Immune Response to JCV
Purpose: To determine precisely where in the body JCV is hiding and how the immune response prevents it from causing brain disease. One of the goals of this study is to characterize determinants of JCV latency and reactivation in the body.
Title: Role of Inflammation in PML
Purpose: To determine precisely which host or viral factors may predict a favorable outcome for PML patients, and the role of inflammation in preventing JCV from causing brain disease. One of the goals of this study is to help establish non-invasive markers of PML evolution by studying the brain metabolism in PML lesions using Magnetic Resonance Imaging (MRI), Magnetic Spectroscopy (MRS) and other advanced imaging modalities.
Title: JC virus reactivation in Multiple Sclerosis
Purpose: To identify biological factors that increase the risk of developing PML while being treated with the MS drug Natalizumab (Tysabri). The study evaluates a patient's immune response against the JC Virus after 18, 24, or 36 months of continuous Natalizumab (Tysabri) therapy, and compares these results to that of control groups. If biomarkers that increase risk can be identified, patients who consider Natalizumab therapy will be better informed as to their individual risk of developing this very rare disease.
If you are interested to refer a patient or if you have any questions about any of these studies, please feel free to contact Igor J. Koralnik, MD at 617-735-4460.