Age-related changes in functions of peripheral blood phagocytes.

Ingestion, digestion and antibody-dependent cell-mediated cytotoxicity (ADCC) of opsonized sheep red blood cells (SRBC), as effector functions of peripheral blood phagocytes, were studied in newborns, children, mature and aged adults. All tested functions changed non-synchronously during the lifetime. The ingestion was maximal in newborns, digestion in children and ADCC in mature adults. The ingestion was minimal in aged, but digestion was minimal both in newborns and aged. Such changes of phagocytes' functions could possibly contribute to differences in immune reactions of the age-groups studied. The study indicates the need for establishing age-adjusted normal values for major granulocyte and monocyte effector functions.