The influence of age and sex on phagocyte chemiluminescence

Abstract

The process of ageing is associated with increased susceptibility to infection. Phagocytes form the primary defence mechanism against infecting microorganisms, but the influence of ageing on phagocyte function remains controversial. In this study we have applied a microtitre plate phagocyte chemiluminescence (CL) assay suitable for clinical use to compare phagocyte oxidative metabolism in younger healthy subjects (age 20-60 years) and healthy older (60-70 years) subjects. Polymorphonuclear leukocytes (PMNL) and monocytes were stimulated using phorbol myristate acetate (PMA), serum opsonized zymosan (SOZ), and non-opsonized zymosan (ZYM) in the presence of both lucigenin and luminol. Monocytes showed a higher luminol-enhanced CL response to PMA in males compared with females in the younger age group. No PMNL differences were observed between the sexes. Although no differences were found in relation to age when cells were stimulated with PMA and SOZ, significantly lower background (unstimulated) CL was obtained from PMNL with luminol. PMNL luminol-enhanced CL responses were also lower in response to ZYM. The findings suggest a reduced response of PMNL from older subjects to minimal stimulation. This could be related to abnormalities in the triggering of the respiratory burst or myeloperoxidase release due to ageing. The influence of age and sex should be taken into account in clinical studies of phagocyte CL.

Natural killer cell activity in patients with major depressive disorder treated with escitalopram

“…The current sample included patients with a wide range of ages (21-69 years) and higher percentage of females. Elderly depressed patients showed an increase in the number of NK cells [32], but the activity was not reported. Gender could be regarded as a factor affecting different components of the immune system, even though the exact relation is not known [33].…”

Neutrophil Oxidative Metabolism in Aged Humans: A Perspective

“…Yet, although the majority of them provided evidence for an impairment of neutrophil oxidative responsiveness (4)(5)(6)(8)(9)(10)(11)(12), others showed a normal (14)(15)(16) or even increased function with age (17). Yet, although the majority of them provided evidence for an impairment of neutrophil oxidative responsiveness (4)(5)(6)(8)(9)(10)(11)(12), others showed a normal (14)(15)(16) or even increased function with age (17).…”

Influence of Age on Oxidative Bursts (Chemiluminescence) of Polymorphonuclear Neutrophil Leukocytes

“…Curiously, investigators of the aging immune system have mainly concentrated on lymphocytes; less attention has been paid to the function of polymorphonuclear neutrophils (PMNs) in the elderly, despite the fact that phagocytes are known to play a major role in primary host Inhibition of PMN Chemiluminescence in Elderly Subjects Gerontology 1998;44:192-197 193 defense against infections [10,11]. Some phagocytic activities have been shown to be impaired in the elderly [12,13], thus leading to their greater susceptibility to infectious agents [14,15] and contributing towards infectioninduced morbidity and mortality.…”