Decreased cell proliferation and altered cytokine production in frail older adults

Background and aims: Frailty is a geriatric syndrome that predicts increased morbidity and mortality. In order to investigate specific immune system modulations that may contribute to frailty, eleven age- and sex-matched pairs of community-dwelling frail and non-frail older adults were identified. Methods: Peripheral blood mononuclear cells (PBMC) were isolated and PBMC proliferation and production of IL-6, tumor necrosis factor (TNF)-α, and IL-10 in the presence and absence of lipopolysaccharide (LPS) were examined. Results: We found that frail subjects had a significantly lower LPS-induced PBMC proliferation ratio compared with non-frail subjects (2.1±0.9 vs 3.1±1.9, p<0.03). In addition, frail subjects had higher IL-6 production by PBMC at 48 hours after LPS stimulation (35678±15637 vs 25178±6342 pg/mL, p<0.03). No significant differences were observed in TNF-α, and IL-10 production between groups. Conclusions: These results suggest that, compared with non-frail controls, frail older adults have both decreased LPS-induced proliferation and increased IL-6 production by PBMC.