Alcohol consumption suppresses an immune-system protein involved in fighting pneumonia, which may explain why alcoholics have an increased risk of the lung infection, a study in mice suggests, ReutersHealth reports.
But transferring the gene for the protein, known as interleukin-17 (IL-17), restored the immune system's ability to fight pneumonia, researchers report in the June issue of the journal Alcoholism: Clinical and Experimental Research.
The findings suggest "that some of the harmful effects of alcoholism on the immune system can be reversed," according to the study's lead author, Dr. Judd Shellito, of the Louisiana State University Health Sciences Center in New Orleans.
In the future, Shellito said in an interview with Reuters Health, alcoholics who develop pneumonia might be treated not only with antibiotics to fight the infection, but also with therapy to restore normal IL-17 function.
He cautioned, however, that more research is needed to confirm that alcohol has the same effect on IL-17 in people.
Shellito and his colleagues added alcohol to the water of one set of mice and compared them with mice that did not consume any alcohol.
When the mice on the normal diet were exposed to pneumonia bacteria, their immune systems produced IL-17 to fight the infection.
In contrast, the researchers did not detect any IL-17 in mice that had been exposed to alcohol.
But Shellito's team was able to reverse the effects of alcohol on the immune system.
Mice that had been exposed to alcohol were injected with the gene for IL-17.
When they were exposed to pneumonia bacteria a few days later, the mice that received gene therapy were no more likely to die from pneumonia than normal mice.
Source: ReutersHealth and Alcoholism: Clinical and Experimental Research 2001;25:872-881.