Autoimmunity in the Elderly: Insights from Basic Science and Clinics - A Mini-Review

Abstract

Advancements in the field of biomedicine, including the control of infectious diseases through antibiotics and vaccination practices and the prevention of chronic disorders, have led to reduced mortality, increased life expectancy and, as such, growth of the older population. Ageing is accompanied by profound morphological and physiological alterations. In particular, the immune system undergoes a complex series of remodeling/restructuring events, involving almost all compartments - both the innate and the adaptive system. This process is termed immunosenescence or immune dysregulation and, basically, includes 3 events: a reduction in immune response, an increase in the inflammatory and oxidation background (inflammaging and oxi-inflammaging), and a production of autoantibodies. While there is an increase in autoimmunity in the elderly, this does not always translate into an increase in autoimmune diseases, which represent an important cause of morbidity and mortality and affect 5-10% of the world population. Each disease involves a specific age group. Generally speaking, most autoimmune diseases have a decreased peak age of onset, except for very few diseases such as giant cell arteritis and primary biliary cirrhosis, which are more prevalent among the elderly, or inflammatory bowel disease, which has 2 peaks of onset, the first one in young subjects and the other in those older than 60 years. Autoimmune disorders in the elderly have unique clinical presentations, and insidious and atypical symptoms may constitute a challenge for the physician. They are generally milder than in adults and can be controlled by a proper therapeutic treatment. However, despite advancements both in basic and clinical sciences, further studies and investigations are warranted and should be carried out in order to dissect the molecular framework induced by ageing.

Keywords: Ageing; Autoantibodies; Autoimmune diseases; Autoimmunity; Elderly; Immunosenescence.