Researchers in Australia have published a case report documenting the rather dramatic response of a severe progressive MS patient to immunotherapy which was designed to boost a specific type of immune response against B Cells latently infected with Epstein Barr Virus, the cause of mononucleosis and a possible cause of MS. The patient experienced:
· A dramatic reduction in inflammatory MRI lesions
· Improvement in symptoms and neurological findings
· A reduction in the production of immunoglobulins within the spinal fluid
The reduction in immunoglobulin being produced within the nervous system and measured in spinal fluid was perhaps the most remarkable finding, as it suggests that this treatment eliminated intrathecal (meaning within the spinal fluid) B cells latently infected with Epstein Barr Virus.
There is a wealth of direct and indirect evidence that Epstein Barr Virus plays an important role in causing MS. Pathological studies reveal nodules of inflammatory cells scattered across the surface of the brain, often in clusters resembling tiny lymph nodes. Many of these cells are a type of lymphocyte, called a B cell, that are infected with Epstein Barr virus. These inflammatory cells appear to directly damage the underlying cortex of the brain, which may trigger an inflammatory response that spreads throughout the nervous system over many years. It is these same B cells that mature to become the type of cells (called plasma cells) that produce the immunoglobulins in the spinal fluid (CSF) that we use to help diagnose MS. We call these immunoglobulins in the CSF oligoclonal bands.
The therapy given to this patient was designed to boost the cytotoxic immune response against EBV infected B Cells. The immune system depends on cytoxic or CD8+ T immune cells to destroy cells infected with viruses, but this cytotoxic response is often lacking in MS patients. They used a novel approach to stimulate a sample of the patient’s blood with AdE1-LMPpoly, a recombinant adenovirus vector that boosts cytotoxic CD8+ T cell responses against Epstein Barr virus proteins expressed by infected B Cells, and then re-injected these boosted cells back into the patient. The patient tolerated the treatment well and improved.
Clearly, these results require confirmation in well designed and controlled clinical trials, but for the first time we seem to have a path forward to finding an effective therapy for MS that is based on a reasonable hypothesis regarding the cause of the disease. I wouldn’t be surprised to find a therapy like this available within 5 years if confirmed by additional studies.
Happy Valentine’s Day