293 Autoimmune autonomic ganglionopathy: the NHNN experience

Abstract

BackgroundAutoimmune Autonomic Ganglionopathy (AAG) is a rare, immune-mediated condition characterised by subacute pandysautonomia. 50% have auto-antibodies to the ganglionic nicotinic acetylcholine receptor (gAChR), affecting synaptic transmission at autonomic ganglia.MethodsWe describe 13 patients (5 female, median age 47) presenting with widespread autonomic failure, confirmed on cardiovascular, sudomotor and pupillometry testing at the National Hospital for Neurology and Neurosurgery (NHNN), and high gAChR antibody levels (>200 pm) measured by radioimmunoprecipitation assay at Oxford University.ResultsOf the 13 patients, 8 had other autoimmune conditions, 3 had antecedent infection and 3 were paraneoplastic. All had orthostatic hypotension, gastro-intestinal and urinary symptoms, 11 had documented pupillary abnormalities (9 mixed sympathetic and parasympathetic deficits, 2 subclinical sympathetic deficits), 11 had secretomotor dysfunction, 8 had generalised/partial anhidrosis, 8 had sexual dysfunction and 7 had evidence of small fibre dysfunction on neurophysiology.Ten received immunomodulatory treatment; 6 plasma exchange and 4 combination treatment including intravenous immunoglobulin, mycophenolate and rituximab. Earlier treatment was associated with greater clinical response.DiscussionPatients with AAG and high gAChR antibody levels have widespread dysfunction of the autonomic nervous system, which can respond dramatically to immunomodulation. Further research is needed to develop robust clinical biomarkers to guide treatment and monitor response.