- Patients will be excluded if they have an active, known or suspected autoimmune disease. Autoimmune disease: Patients with a history of inflammatory bowel disease are excluded from this study, as are patients with a history of symptomatic autoimmune disease (e.g., rheumatoid arthritis, systemic progressive sclerosis (scleroderma), systemic lupus erythematosus, autoimmune vasculitis e.g., Wegener's Granulomatosis); motor neuropathy considered of autoimmune origin (e.g. Guillain-Barre Syndrome).