US researchers have confirmed that binge drinking undermines the immune system and weakens the body’s ability to fight off infection for at least 24 hours afterwards by inhibiting certain signalling molecules that launch pro-inflammatory responses.

The research was the work of Stephen Pruett, currently at the College of Veterinary Medicine at Mississippi State University and Ruping Fan of Louisiana State University Health Sciences Center and is due to be published in the journal BMC Immunology.

Previous studies using mice showed that binge drinking, defined as drinking large amounts of alcohol over a short period of time with the intention of getting drunk, stops the body making pro-inflammatory cytokines, signalling molecules that launch immune responses to infection.

For this study, Pruett and Fan focused on the effect of heavy drinking on the TLR4 (toll-like receptor 4) protein which plays a key role in recognizing pathogens and then triggering production of the appropriate cytokines.

They compared the in vivo (using live mice) and in vitro (in test tubes or cultures) effects of alcohol on cytokines and TLR4 and found that acute exposure to alcohol stops the body making certain key pro-inflammatory cytokines.

Pruett and Fan suggested that ethanol suppresses TLR4’s ability to send signals that would normally tell the immune system to make inflammatory cytokines.

The results from the in vivo and in vitro tests were similar except in live mice they were able to discern more detail about ethanol’s ability to inhibit NF-[kappa]B, a DNA transcription activator that is triggered by pathogenic stimuli and is known to control expression of some of the cytokines that are inhibited by alcohol.

The researchers also found that the after effects lasted for a day at least: some cytokines were not on infection guard duty 24 hours after the binge.

Pruett told the press that:

“The time frame during which the risk of infection is increased might be at least 24 hours.”

“A persistent effect of ethanol on cells is indicated, such that inhibition of the response of some cytokines occurs even after the ethanol is cleared,” he added.

“Ethanol inhibits LPS-induced signaling and modulates cytokine production in peritoneal macrophages in vivo in a model for binge drinking.”
Stephen B Pruett and Ruping Fan.
BMC Immunology, In Press.

Sources: BioMed Central, National Library of Medicine (MESH).

Written by: Catharine Paddock, PhD