Immunoregulation in aging.

Senescence of the immune system leads to a decline of functional capacities of lymphoid cells. In this regard, evidence has been provided for a reduction of T and B cell-mediated responses. T-B regulation is also affected by the aging process. Since the proportion of lymphocytes is similar to that observed in young donors, either intracellular or extracellular factors may play an important role in the impaired immunoresponsiveness. An intrinsic defect of T or B cells has been in fact postulated. However, soluble suppressive factors or decreased LK production seem to represent the key events involved in the decline of the immune response. Nevertheless, over the past few years emphasis has been given to the increased lymphocyte membrane microviscosity in the elderly [Rivnay et al: Mech Ageing Dev 10: 71-79, 1979]. All together, these findings suggest a multifactorial therapeutic approach for the correction of the impaired immune response in aged individuals.