Impaired Immune Function in a Homeless Population with Stress-Related Disorders

Abstract

Objective: Homeless people suffer high levels of psychological distress. The aim of the present work was to study the immune function in a group of homeless people with stress-related disorders and compare it with that of healthy non-homeless controls. Methods: We included in the study 40 homeless persons and 40 housed controls recruited from the population of Madrid and matched for age and gender. Samples from peripheral blood were collected and we studied several leukocyte functions previously described as good health and survival markers [adherence, chemotaxis, phagocytosis, superoxide anion levels, lymphocyte proliferation in response to phytohemagglutinin, NK activity and cytokine (IL-2, TNF-α) levels], as well as other related parameters, such as plasma cortisol levels and total antioxidant capacity. Results: There was a strongly suppressed immune response in the homeless group, with decreased adherence, chemotaxis, phagocytosis, superoxide levels, lymphoproliferation and NK activity. IL-2 and plasma antioxidant levels were also impaired. Conclusions: These findings suggest an altered immune function in the homeless population that might be responsible for the higher morbidity and mortality of homeless people. In addition, the present work points out directions for future research attempting to increase the quality of life and health status of homeless individuals, since it shows that oxidative stress seems to play a key role in this immune function impairment.

Activation of the sympathetic nervous system modulates neutrophil function

“…Collectively, our findings are supportive of an immunosuppressive modulatory role for NA on neutrophil function. In fact, the immunosuppressive effect of sympathetic activation has been widely demonstrated in the context of both psychological stress models and exercise science, whereby psychological stressors activating the “fight or flight” response and high‐intensity exercise primarily impair immune function and increase susceptibility to infection . Numerous studies have observed that elite athletes commonly suffer symptoms of upper respiratory tract infections .…”

“…In fact, the immunosuppressive effect of sympathetic activation has been widely demonstrated in the context of both psychological stress models and exercise science, whereby psychological stressors activating the "fight or flight" response and high-intensity exercise primarily impair immune function and increase susceptibility to infection. [47][48][49] Numerous studies have observed that elite athletes commonly suffer symptoms of upper respiratory tract infections. 50 Moreover, studies examining neutrophil function following exercise have also shown that high-intensity bouts of exercise and exercise for longer durations result in impaired oxidative burst in response to stimulation.…”

Models of Aging of Neuroimmunomodulation: Strategies for Its Improvement

“…These animals show altered behavior, immunosenescence and oxidative stress. Moreover, human subjects with stress-related disorders and suffering from anxiety or depression show a significant immunosenescence and oxidative stress [7] .…”

Influence of Stress and Depression on the Immune System in Patients Evaluated in an Anti-aging Unit

“…In humans, several studies have reported that depression or stress situations such as bereavement, a divorce, demanding work environment, or students in exam periods produce a decrease in NK, neutrophil, and lymphocyte activities such as lysis, proliferation, and chemotaxis, making the activities of these immune cells good markers of immune status in patients (Irwin et al, 1988;Schleifer et al, 1996;Andersen et al, 1998;Benschop et al, 1998;Byrnes et al, 1998;Bosch et al, 2005;Arranz et al, 2009;Boscolo, 2009). Stress and depression also modulate the production of hormones such as adrenaline, corticoids, and catecholamine that in turn influence the immune system (Leonard, 2010).…”