Sepsis is a complex condition that is initiated by infection. The incidence of sepsis and its severity are higher at an older age (mean age of approximately 65 years). Clinical manifestations of sepsis are derived from systemic inflammatory response syndrome. Age‐related defects in immunity are shown by changes in cellular and humoral immunity. Recent studies have shown significant changes in the innate response (e.g., changes in toll‐like receptor expression, abnormal activation of mitogen-activated protein kinases, and production of reactive oxygen species) in older people. Transcriptomic analysis on a large scale has provided interesting information showing that specific groups of patients actually have singular profiles for inflammatory responses. Findings from our research group have identified major molecular pathways that are particularly affected in older people during sepsis. Oxidative phosphorylation pathways and mitochondrial dysfunction are altered the most in older people with sepsis compared with younger patients with sepsis. These pathways might have a pivotal role in worsening clinical outcomes compared with younger people with sepsis. The mechanisms leading to specific dysfunction of several signaling pathways in the immune response of older people are complex and appear to involve multiple factors, including environmental factors, microRNAs, and epigenetic changes.
Part of the book: Sepsis