Immunosenescence revisited. Does it have any clinical significance?

Immunosenescence refers to the influence of aging on the immune system. Numerous problems are encountered in studying this topic, the main one being the influence of concomitant disease. Despite the great efforts that have been devoted to research in this field, the results of studies performed to date have not been convincing and, until now, no sound scientific evidence has emerged to show that immunosenescence is clinically significant. The only possible exceptions to this are the discovery of a selective defect in cell-mediated immunity and the reactivation of varicella zoster virus. Therefore, many more, and better designed, studies will have to be conducted before the full clinical impact of immunosenescence can be delineated.