Alcohol intoxication perturbs immune system of aged individuals

The immune system in the elderly is dysfunctional and infections are more prevalent, more severe, and harder to defeat. Drinking alcohol has a variety of damaging effects on the immune system and organs - like the gut, liver and lung - which can be worsened by pre-existing conditions as well as consumption of prescription and over-the-counter medications that aged individuals often take. This presentation addresses how alcohol affects the elderly more dramatically, and also suppresses their ability to battle infections, like pneumonia, much more severely than it does younger individuals.

"Our laboratory has been studying inflammatory and immune responses in the aged for well over a decade," said Brenda J. Curtis, Ph.D., a research assistant professor at the University of Colorado Denver. "We know that even healthy elderly individuals have an elevated basal inflammatory state, known as 'inflamm-aging.' Advanced age alone is a risk factor for a poor prognosis after injury or infection. Adding alcohol to the fragile immune milieu of the aged reduces their ability to fight infections."

"Our research suggests that alcohol intoxication perturbs the immune system of the aged both throughout the body and in local regions, like the lung," added Elizabeth J. Kovacs, Ph.D., director of Burn Research
and professor in the department of surgery at the
University of Colorado Denver / Anschutz Medical Campus. "We have shown that alcohol exposure makes macrophages less effective at clearing pathogens and releasing molecules important for recruiting other immune cells to the site of infection, and that this is worsened in the elderly."

Curtis and Kovacs will present their research at the 39th Annual Research Society on Alcoholism in New Orleans June 25-29, 2016.

Innate immune cells control the immediate response to an infection, including neutrophils and macrophages, Curtis explained. These cells work together to find and eradicate infectious organisms. However, drinking alcohol can impair innate immune function, thereby rendering the individual more susceptible to infections.

"This is due in part to direct effects of ethanol on innate immune cells," said Curtis. "Even short-term exposure of macrophages to alcohol reduces their ability to migrate to a site of infection as well as their ability to destroy the pathogen."

"In addition, the effects of alcohol on the elderly are more potent than they are in younger individuals in part because of the pro-inflammatory state of the aged," noted Kovacs. "Aged individuals also have decreased lung function and cough strength, which further escalates the risk for developing pneumonia."