Comparison of Polymorphonuclear Leukocyte Functions in Elderly Patients and Healthy Young Volunteers

Abstract

Objective: To compare the polymorphonuclear leukocyte (PMN) functions (phagocytosis and intracellular killing activity) of elderly patients with healthy young volunteers. Subjects and Methods: Fifty-nine elderly patients who had various diseases (cancer, hypertension and diabetes mellitus, DM) and 10 healthy young volunteers were included in this study. Ficoll-Hypaque gradient centrifugation was used to isolate PMNs from venous blood containing EDTA (0.1 g/ml). Phagocytosis and intracellular killing activity of neutrophils were assayed using a modification of Alexander’s method, in which serum opsonins, number of neutrophils and number of microorganisms are standardized in order to detect both increases and decreases in phagocytosis and intracellular killing as well as combined abnormalities of these two functions. The least significant difference test was used to compare the results in the two groups. Results: Phagocytic activity of PMNs from patients with cancer was significantly higher than that of healthy young volunteers (p < 0.05) and elderly patients with hypertension and DM (p < 0.05). There was no statistical difference between the phagocytic activity of PMNs from elderly patients with hypertension and DM and healthy young volunteers (p > 0.05). The intracellular killing activity of PMNs from elderly patients with hypertension, DM and cancer was significantly lower than that of healthy young volunteers (p = 0.001, p < 0.0001, p = 0.003, respectively). Conclusions: The intracellular killing activity of PMNs from elderly patients was significantly decreased when compared with that of healthy young volunteers. Ageing, chronic diseases and drugs used in the treatment of these elderly patients may be the cause for decreased intracellular killing activity.

Neutrophils are immune cells preferentially targeted by retinoic acid in elderly subjects

“…Innate immunity is mediated by a diverse group of cell types and mechanisms, including monocytes/macrophages, natural killer (NK) cells, dendritic cells, neutrophils (PMNs), eosinophils and basophils, and by the elaboration of cytokines. Given that PMNs are the largest fraction of white blood cells and the first line of defense against pathogens, the literature contains numerous but inconsistent findings on the effect of aging on PMN numbers and functions (adhesion, chemotaxis, phagocytosis, radical oxygen species (ROS) production) (see review [4-7]) (table 1) [8-26]. These conflicting data may result from difficulties in distinguishing age-dependent specific changes in the immune system.…”

Interplay between Inflammaging, Frailty and Nutrition in Covid-19: Preventive and Adjuvant Treatment Perspectives

“…In the innate arm, the neutrophils show reduced chemotaxis, phagocytic activity, and intracellular killing of the pathogens. These cells also present defective ROS production ( 57 , 58 ). The macrophages become hyperreactive due to inflammatory cytokines in blood flow.…”