Abstract
Objective To describe the clinical, radiological and pathological features of a novel demyelinating disease.
Methods 105 patients with multiple sclerosis (MS) were examined for phenotypic differences radiologically, and their sera were tested for novel autoantibodies using a solid phase, indirect, immunofluorescence method. The characteristics of patients that had a specific autoantibody in their sera, were compared to a cohort of 163 conventional MS patients (CMS).
Results Three of 105 (2.8%) MS patients had a serum autoantibody directed against vesicles of the Purkinje cell layer, synaptic molecules in the molecular layers of the cerebellum and hippocampus and the surface of choroid plexus epithelium. AQP4 and MOG antibodies were absent. Oligoclonal bands were absent in one patient. None of the other MS patients, 64 healthy controls or 78 other neurological controls exhibited this antibody.
Patients with synaptic antibodies had recurrent transverse myelitis, occasional optic neuritis and short, swollen cord lesions affecting the grey matter of the cord, in acute phase. Spinal cord demyelination was much more common in these patients (2.8 cord to 1 brain lesion) compared to CMS (1 cord to 5.8 brain lesions). Antibody positive patients suffered disease reactivation on Fingolimod (n=1) or responded poorly to Natalizumab (n=1). The disease was controlled with plasma exchange and Rituximab. The autoantibody bound to choroid plexus cells in culture from all three patients.
Discussion Synaptic antibodies and spinal predominant demyelination (SAPD) can be diagnosed with a new serological test and responds to treatment directed at humoral immunity.
