[Aging and the cutaneous immune system].

The changes in the immune system during the ageing process have been described in numerous publications, which are sometimes contradictory. The study of cell mediated immunity and of hormonal immunity provide only a partial reflection of the smooth working of the cutaneous immune system, which is dependent on fragile cell interactions between T lymphocytes, cells of Langerhans and keratinocytes, which involves numerous soluble mediators. Three possible mechanisms leading to or contributing to the decline in immune function with age should be considered: a modification of the distribution of lymphocyte subpopulations (the T helper lymphocytes and T-suppressing lymphocytes are affected by age in particular), changes in the mechanisms of suppression and changes in the maturation of B and T lymphocytes.