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)-alpha, 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 3.11+/-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-alpha, 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.