With age, most individuals after 55-60 years, there has been a gradual, increasingly profound immunodepression. The speed of this process has a purely individual character.
It is proved that the absolute number of T – and b-cells is not reduced, however, changes their functional activity. At persons of senile age (after 80 years) especially affects the function of T-system of immunity, in particular, the recognition of ALLO-antigens by macrophages and lymphocytes, suppressed activity of helper T-cells (as TX2, and Txl), perverted suppressor function of the immune system. Very likely an imbalance in the cytokine-ing the regulation of immune responses (in relation to the elderly, this problem is still poorly investigated).
In connection with razbalansirovat system physiological immuno-regulation during aging increases the frequency of malignancies and autoimmune disorders.
On top of that due to the lower metabolic activity in phagocytes and other cells responsible for the function of nonspecific anti-infective reactivity in older persons are becoming more frequent chronic and indolent bacterial, viral and fungal infections.
Thus, the typical diseases of old age are directly linked to suppression of immunoreactivity due to the profound changes in the population structure of T-cells and their functions, and also due to the decrease in the activity of cells involved in realization of nonspecific cellular and humoral reactions.