Diagnosing autoimmune diseases of the nervous system
Autoimmune diseases are caused when the body makes antibodies that attack our own proteins.
Research by Professor Angela Vincent FRS and her team from the Nuffield Department of Clinical Neurosciences has created a step change in the diagnosis and treatment of disorders including myasthenia gravis (muscle weakness) and forms of encephalitis (inflammation of the brain).
The majority of cases of autoimmune myasthenia gravis are caused by antibodies targeting the acetylcholine receptor. However, approximately 15% of patients have a previously unexplained form of the disease. The cause of a great many of these unexplained cases was identified in 2001 when Angela Vincent and her team identified antibodies to the protein MuSK in these individuals. This has had a profound effect on the diagnosis and treatment of autoimmune myasthenia. As a result the European Federation of Neurological Societies has revised its guidelines highlighting that two widely used treatments may not be appropriate in these cases. More recently they have shown how 'cell-based' antibody tests can improve the diagnosis of myasthenia and be applied to other diseases as well, particularly those described below.
Angela Vincent’s team have also shown that autoantibodies targeting potassium channel (VGKC) and associated proteins, and the NMDA receptor, can be the cause of two different forms of encephalitis which many would previously have thought were due to viral infections. Crucially, as autoimmune brain disorders often respond dramatically to immunosuppressive therapy, these findings provide new hope for these patients. As a result the European Federation of Neurological Societies, the Association of British Neurologists and the British Infection Association guidelines all recommend that potential autoimmune causes of encephalitis should be high on the list of possible diagnoses. In this way effective treatment can often be provided earlier.
The success of Angela Vincent’s work led to the creation of the first, and the largest, Clinical Neuroimmunology service to test NHS samples in the UK. Providing the optimal antibody testing for another disease, neuromyelitis optica, supports the NHS national service established between Oxford and Liverpool for the clinical care of these patients. Demand for the service overall has expanded fivefold in recent years and in 2012 over 27 thousand samples were tested; mostly from the NHS but also from across Europe and elsewhere. Any proceeds from this service are fed back into improving antibody testing as well as frontline medical research.