Autoimmune autonomic ganglionopathy (AAG) is a rare disease that results in severe dysautonomia (disorder of autonomic nervous system function). Many patients are unable to carry out activities of daily living due to autonomic symptoms that do not respond well to therapy (such as drops in blood pressure while standing). The recent discovery of antibodies that cause AAG has stimulated interest in immunomodulatory therapy (therapies that modify the functioning of the immune system). Studies in which a positive clinical response to these therapies have been reported in patients with AAG using immunomodulatory therapy as a treatment.