In the previous OCTO longitudinal study, we identified an immune risk phenotype (IRP) of high CD8 and low CD4 numbers and poor proliferative response. We also demonstrated that cognitive impairment constitutes a major predictor of nonsurvival. In the present NONA longitudinal study, we simultaneously examine in a model of allostatic load IRP and compromised cognition in 4-year survival in a population-based sample (n = 138, 86-94 years). Immune system measurements consisted of determinations of T-cell subsets, plasma interleukin 6 and cytomegalovirus and Epstein-Barr virus serology. Interleukin 2 responsiveness to concanavalin A, using data from the previous OCTO (octogenarians) immune study, hereafter OCTO immune, was also examined. Cognitive status was rated using a battery of neuropsychological tests. Logistic regression indicated that the IRP and cognitive impairment together predicted 58% of observed deaths. IRP was associated with late differentiated CD8+CD28-CD27- cells (p < .001), decreased interleukin 2 responsiveness (p < .05) and persistent viral infection (p < .01). Cognitive impairment was associated with increased plasma interleukin 6 (p < .001). IRP individuals with cognitive impairment were all deceased at the follow-up, indicating an allostatic overload.
As a part of an ongoing longitudinal investigation, this study examined relationships between survival and selected immune system parameters in a sample (n = 102) of very old individuals (86-92 years at the time of initial immune system data collection). Analyses were performed comparing initial time-point measurements from those individuals who were alive (n = 75) and those who were deceased (n = 27) two years after initial data collection. Immune system measurements consisted of determination of peripheral blood lymphocytes and lymphocyte subsets, as well as T-cell responses to activation by Concanavalin A. Cluster analysis identified a subgroup associated with nonsurvival which indicated characteristics that included: poor T-cell proliferative responses, high CD8 percentages, and low CD4 and CD19 percentages. This multivariate analysis suggested that combinations of immune system parameters predict two-year survival otherwise not apparent when single immune system parameters were evaluated in the elderly.
SUMMARY In all of 12 patients with chronic liver disease, whose platelet dynamics were investigated by the 51Cr-labelling technique in association with surface counting, platelet survival was reduced and in Ithe splenic platelet pool was increased. Surface counting showed high initial spleen:liver ratios in eight patients, and in four there was evidence of progressive destruction of platelets in the spleen. In one patient, subsequently shown to have a hepatoma, progressive accumulation of platelets was noted at the tumour site.
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