Samson LD, et al. - Researchers examined how frailty is associated with immunological aspects of human aging in the Doetinchem Cohort Study (DCS). Frailty index scores based on 36 health parameters were obtained for each individual in the DCS and were used to define three health groups (healthy, intermediate, and frail), stratified by age and sex. Blood samples were obtained in a sub-cohort (n = 289, 60–85 years, selected by balanced random sampling per frailty group) to ascertain absolute numbers of leukocyte subsets. According to findings, frail elderly individuals tend to experience chronic and stable low-grade inflammation compared with their age- and sex-matched peers, which is associated with a myeloid cell lineage expansion. Both sexes displayed these findings; however, they were more pronounced among women. These findings may support monitoring the elderly with clinically significant immunological decline.