Dendritic cells (DC) are potent antigen-presenting cells that initiate and regulate T-cell responses. In this study, the numbers and functional cytokine secretions of plasmacytoid and myeloid DC (pDC and mDC, respectively) in peripheral blood from young and elderly subjects were compared. Overall, pDC numbers in peripheral blood were lower in healthy elderly compared with healthy young subjects (p = 0.016). In response to influenza virus stimulation, isolated pDC from healthy elderly subjects secreted less interferon (IFN)–α compared with those from healthy young subjects. The decline in IFN-α secretion was associated with a reduced proportion of pDC that expressed Toll-like receptor–7 or Toll-like receptor-9. In contrast, there was little difference in the numbers and cytokine secretion function between healthy young and healthy elderly subjects (p = 0.82). However, in peripheral blood from frail elderly subjects, the numbers of mDC were severely depleted as compared with either healthy young or elderly subjects (p = 0.014 and 0.007, respectively). Thus, aging was associated with the numerical and functional decline in pDC, but not mDC, in healthy young versus elderly subject group comparisons, while declining health in the elderly can profoundly impact mDC negatively. Because of the importance of pDC for antiviral responses, the age-related changes in pDC likely contribute to the impaired immune response to viral infections in elderly persons, especially when combined with the mDC dysfunction occurring in those with compromised health.

OBJECTIVE:The purpose of the study was to determine whether a new method of scoring the Clock Drawing Test (CDT) is a reliable and valid method for identifying older adults with declining driving competence. DESIGN: Prospective cohort study.SETTING: An outpatient driving evaluation clinic. PARTICIPANTS:One hundred nineteen community-dwelling, active drivers with a valid driver's license, aged 60 and older referred for driving evaluation. MAIN OUTCOME MEASURES:The CDT and a driving test using a STISIM Drive simulator.RESULTS: The CDT showed a high level of accuracy in predicting driving simulation outcome (area under the receiver-operator curve, 0.90; 95% confidence interval, 0.82 to 0.95). CDT scoring scales were comparable and all correlations between CDT scores and driving performance were negative, implying that as the CDT score decreases, the number of errors increases. Interrater reliability of CDT scores was 0.95. Subjects scoring less than 5 out of 7 points on the CDT made significantly more driving errors, hazardous and in total (Po.001). CONCLUSIONS:The CDT can help establish problems with executive function and indicate the need for a formal driving evaluation. Our CDT scoring scale is a reliable, valid, and time-effective screening tool for identifying elderly drivers in need of further evaluation. D riving places demands on attention, memory, problem solving, and information processing, cognitive skills that often decline with aging. Older drivers crash at a rate second only to the youngest drivers.1,2 Older driver involvement in fatal crashes is projected to increase 155% by 2030, accounting for 54% of the total projected increase in fatal crashes among all drivers.3 As the population ages and the number of older drivers increases, declining driver competence becomes an urgent public health problem and a challenge for health professionals to recognize impaired driving ability in the elderly. Declining driving competence is associated with impairments in vision, functional abilities, and cognition. However, it is especially true that cognitive impairment is overlooked in the context of a brief office visit as are issues related to driving ability. Cognitive impairment and dementia are surprisingly prevalent among older apparently healthy individuals, affecting up to one third of people aged over 65 years, yet it remains undiagnosed in 25% to 90%. [4][5][6][7] Consequently, the impact on driving ability persists unnoticed. The responsibility for determining the driving fitness of older adults is increasingly falling upon the medical profession; however, clinicians have few tools and few data on which to base decisions about driving. A brief and time-efficient screening test is needed to assist clinicians to identify older drivers who may represent a public health hazard and need to undergo a driving evaluation.The purpose of the study was to determine whether a new method of scoring the Clock Drawing Test (CDT) is a reliable and valid method for identifying older adults with declining driving competen...

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