Circulating progenitor cells and the elderly: a seven-year observational study.

Cardiovascular (CV) diseases and related complications are the main causes of morbidity and mortality in the elderly. CV progenitor cells, including CD34+ cells, play a role in delaying the progression of atherosclerosis. In the present study we observed 100 octogenarians for seven years, in order to address the question of whether CD34+ cell number is a predictor of longevity in selected survivors. We also checked for associations of cell expression of manganese superoxide dismutase (Mn-SOD), catalase (CAT), and glutathione peroxidase type-1 (GPx-1) antioxidative enzymes, with number of CD34+ progenitor cells and mortality. We found that in very old subjects the number of CD34+ cells at baseline were higher in subjects who reached older age at death or were still living at the end of observation period, with respect to subjects who died from all causes, including CV deaths. On the other hand, HDL-C plasma levels and, with the exception of diabetes, the classic CV risk factors (hypertension, smoking, hypercholesterolemia) showed a loss of their predictive power. A significant association between the redox system of CD34+ cells and mortality was also observed. These data suggest that, even in the elderly, CD34+ cells maintain their role in predicting mortality. CD34+ cells could thus be considered as a biomarker of longevity.