In the elderly, cell marker expression is extremely important due to the decline of the immune system observed in advancing age [ 18, 60, 61], with a decreased functional capacity observed in studies of responses to mitogen stimulation.
Recently, a phase II trial demonstrated that the botezomib-containing combination treatment in elderly mantle cell lymphoma patients results in high complete responses and prolonged progression-free survival with predictable and manageable toxic effect.
Furthermore, at least two lines of evidence suggest that stem cell-based tissue-replacement therapies might be hindered in the elderly, because all cells along the developmental lineage (e.g., stem cells, more differentiated progenitor cells or even tissues containing a pool of precursors) might rapidly 'age' and fail to contribute to organ repair when introduced into the old organism in vivo.
Thus, radiation may cause a major impact in the elderly, whose aging cells already naturally showed an impaired redox system.
In the elderly, the B cell production rate decreases, however the number of peripheral B cells remain constant [ 17, 18].
In young subjects the CD45RA/CD45RO T cell ratio was higher (p < 0.01) than in T cell of elderly subjects, which is expected based on the higher frequency of memory cells (identified as CD45RO-expressing cells).
We demonstrated that CD4+ T cells in elderly humans and aged mice showed impaired IL-2 receptor (IL-2R) expression, IL-2 production, and cell division.
Ex vivo stimulation decreased CD25 expression, IL-2 production, and proliferation to a greater extent in CD4+ T cells from elderly patients and aged septic mice than in those from adult patients and young septic mice.
TLR expression is reportedly decreased in the immune cells of elderly human donors and aged mice (Panda et al., 2010; Shaw et al., 2013).
While our current study focused on the role of CD4+ T-cells and the function of regulatory T-cells in elderly recipients, the importance of age-dependent changes of CD8+ T-cells is well-recognized.
