Lysosomal enzymes of neutrophils and lymphocytes in aged subjects

The activity and intracellular localization of some main lysosomal enzymes such as: acid phosphatase (AP), beta-glucuronidase (GR) and N-acetyl-beta-glucosaminidase (GS) in peripheral blood neutrophils and lymphocytes has been studied in a total group of 141 subjects of both sexes aged 18 to 90 years, divided into two age groups consisting of 81 younger controls aged 18 to 42 years and 60 older subjects aged 66 to 90 years. The most important finding concerning the neutrophil system was the decrease in the aged group of enzyme-positive cells not accompanied by alterations of AP and GR intracellular activity whereas the activity of GS was increased in older subjects. The lymphocytes of aged persons were characterized by lack of normal lysosomal granules and diffusion of AP, GR and GS within the cell cytoplasm. The authors discuss the above changes in the neutrophils and lymphocytes of aged persons within the overall present-day knowledge on ageing of the neutrophilic and lymphocytic series.