Immunosenescence: the association between leukocytes, cytokines and chronic diseases

ABSTRACT The aging process and its natural consequence – oldness – are one of the major concerns of modern society, especially due to the rapid growth of the elderly population when compared to other age groups. This particular growth brings about significant changes in our civilization and also challenges society in several aspects, especially in those concerning health issues. This latter aspect is probably the most emphasized and worrisome, since a large proportion of older-adults bear at least one chronic disease or health restrictions. Regarding biological features, the aging process is a complex phenomenon that submits the organism to several physiological alterations, affecting its integrity and allowing the manifestation of chronic illnesses in old-age, with impact in the elder’s health and quality of life. Among the systems of the organism, the nervous, endocrine and immune systems suffer more changes as one grows old. This literature review deals with the aging process in view of alterations of the immune system known as immunosenescence. It will analyze aspects related to numerical, morphological and functional alterations of different cell types that form the system, with emphasis to the biological effects of the major inflammatory mediators (citokines) in the onset of chronic-degenerative diseases inherent to the aging process.