Plasma Exchange for Autoimmune Autonomic Failure

This study will explore whether an antibody is influencing the autonomic nervous system, and if its removal will eliminate signs and symptoms of failure in that system. The autonomic nervous system is responsible for many automatic changes involved in everyday activities, such as standing up, digesting food, and exercising in the heat. Antibodies fight germs but sometimes cause health problems. Removal of the antibody is done through a procedure called a plasma exchange. Patients with primary chronic autonomic failure and a circulating antibody to what is called the neuronal nicotinic receptor may be eligible for this study. To be eligible, patients will have participated in an earlier study, protocol number 03-N-0004. Patients will undergo tests and procedures that include an electrocardiogram, and blood collection for hepatitis, HIV, and pregnancy. Blood will be tested for a complete blood count, clotting factors, and chemistries. There will also be tests for liver function, kidney function, cortisol, and thyroid. Participants will be tested for signs and symptoms of autonomic failure, and will be asked to complete questionnaires about various symptoms before the plasma exchange, 1 or 2 weeks afterward, and then monthly or bimonthly for up to 1 year. Patients will undergo a series of other tests. In one test, a patient is upright and blows against a resistance (Valsalva maneuver). The quantitative sudomotor axon reflex test (QSART) uses iontophoresis, involving application of acetylcholine, a chemical messenger, and a small amount of electricity. QSART examines the regulation of sweating, a particular aspect of the autonomic nervous system. There will be a test using edrophonium, given intravenously (IV), to evaluate that drug's effects on the heart, skin, glands, gastrointestinal activity, bladder tone, and salivation. A glucagon test, also by IV, will show patients' ability to release the hormone adrenaline. The plasma exchange will be performed by use of an a