Immune System Dysfunction in the Elderly

Eduardo Fuentes,Manuel Fuentes,Iván Palomo,Marcelo Alarcón

doi:10.1590/0001-3765201720160487

Eduardo Fuentes, Manuel Fuentes + Show 2 more

Open Access

https://doi.org/10.1590/0001-3765201720160487

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Abstract

Human aging is characterized by both physical and physiological frailty that profoundly affects the immune system. In this context aging is associated with declines in adaptive and innate immunity established as immunosenescence. Immunosenescence is a new concept that reflects the age-associated restructuring changes of innate and adaptive immune functions. Thus elderly individuals usually present chronic low-level inflammation, higher infection rates and chronic diseases. A study of alterations in the immune system during aging could provide a potentially useful biomarker for the evaluation of immune senescence treatment. The immune system is the result of the interplay between innate and adaptive immunity, yet the impact of aging on this function is unclear. In this article the function of the immune system during aging is explored.

Highlights

Human aging is characterized by both physical and physiological frailty
Infections, cancer and autoimmune diseases occur more frequently in the elderly, and many factors contribute to this, the age-related remodeling of the immune system, termed immunosenescence, Correspondence to: Eduardo Fuentes E-mail: edfuentes@utalca.cl plays a major role (Bueno et al 2014, Mocchegiani et al 2009, Sharma et al 2014)
Immunosenescence describing alterations including the decline of immune responses with age is comprised of inappropriate elevations, decreases, and dysregulated immune responses, leading to more severe consequences of bacterial and viral infections and reduced responses to vaccination (Montgomery and Shaw 2015)

Summary

INTRODUCTION

Immunosenescence involves age-associated restructuring changes of innate and adaptive immune functions (Baeza et al 2011, Dace and Apte 2008). An alteration in pathogen destruction mechanism mediated by neutrophil extracellular traps (NETs) was demonstrated, which it is one of the results of increased infections in older individuals (Brinkmann and Zychlinsky 2007) Besides these neutrophils have lower activation against TNF-α, interleukin (IL)-8 and lipopolysaccharide (LPS), with a consequent reduction in production of ROS (Hazeldine et al 2014, Summers et al 2010). Macrophages main function is involved in phagocytosis synthesize pro-inflammatory cytokines TNF-α, IL-1, IL-6 and IL-8, in addition to processing and presenting antigens to T cells and participating in adaptive immunity (Weiskopf et al 2009, Shi and Pamer 2011). We will describe the effect of aging on the function of B and T lymphocytes (Figure 1)

B LYMPHOCYTES

Findings

CONCLUSIONS