From Appearance of Adrenal Autoantibodies to Clinical Symptoms of Addison's Disease: Natural History.

Recent progress in the immunopathology field has greatly improved our understanding of the natural history of autoimmune diseases, particularly of Addison's disease. Addison's disease is known to be a chronic illness characterized by adrenocortical gland insufficiency that develops following a long and mainly asymptomatic period, characterized by the presence of circulating autoantibodies directed to adrenal cortex antigens. In this chapter we describe the groups of subjects at risk of developing Addison's disease, together with the diagnostic tests considered the most appropriate for evaluating adrenal function: determination of basal plasma adrenocorticotropic hormone (ACTH) levels, plasma renin activity, plasma aldosterone and cortisol levels, and cortisol levels after intravenous stimulation with ACTH (ACTH test). The employment of specific clinical, immunological and functional criteria in the subjects with autoantibodies to the adrenal cortex allows identifying those at risk of developing overt disease. The independent risk factors for the progression to adrenal failure have also been identified and they contribute to different risks of developing clinical Addison's disease. Based on the risk level, the subjects should be monitored over time to observe early signs of adrenal dysfunction, and start substitutive treatment as soon as possible. For patients presenting with high risk, prevention strategies and trials might be available.