Immune-inflammatory responses in the elderly: an update

Background In Western countries the number of persons 65 years or older is most rapidly increasing. The percentage of people over 60 in the world has risen from 9.2% in 1990 to 11.7% in 2013 and, according to several estimates, it will reach 21% by 2050. It is expected to exceed the number of children for the first time in 2047. In addition, the number of persons above 80 years is projected to increase even more dramatically from a worldwide total of 125 million in 2015 to 434 million in 2050. Therefore, the problem of the elderly health is now a priority in medicine [1]. In May 2012, a group of scientists and clinicians developed a consensus statement to highlight the importance of a common view on ageing and healthy lifespan [2]. As reported in the panel, ageing is most likely one component of life, which first emerged in economically developed countries and results from a breakdown of self-organizing system and reduced ability to adapt to the environment. Ageing processes are defined as those that amplify the vulnerability of subjects, as they become older, to the factors that finally lead to death. In Western countries, the mortality rate increases 25 times more rapidly in individuals over 60 years old compared to people aged 25–44. Causes of death in aged are increased compared to individuals between 25 and 44 years old: cancer 43-fold, pneumonia and influenza 89-fold, heart diseases 92-fold, and stroke and chronic lung disease greater than 100-fold. These data suggest a key role for immunity in the survival of the elderly because resistance to these diseases depends at least in part on optimal immune function [3].