Living near busy roads with high levels of air pollution raises lung transplant patients' risk of organ rejection and death, but some antibiotics lower that risk, a new study shows.
Researchers examined data gathered from more than 5,700 lung transplant patients in 10 European countries between 1987 and 2013.
The analysis revealed that patients who lived in areas where air pollution was above maximum levels recommended by the World Health Organization (WHO) were 10 percent more likely to die than those in areas with lower levels of pollution.
But this increased risk of death was not seen among patients who took a class of antibiotics called macrolides, which include azithromycin (Zithromax) and clarithromycin (Biaxin), according to the study presented Tuesday at a meeting of the European Respiratory Society in Amsterdam.
"Short and long-term exposure to air pollution has been linked to an increase in deaths from respiratory diseases, particularly among vulnerable populations. Lung transplant patients are among the most vulnerable because they have weakened immune systems due to the immunosuppressive drugs they have to take to prevent organ rejection," study author Dr. David Ruttens said in a European Lung Foundation news release. Ruttens is a specialist in respiratory medicine at the University of Leuven in Belgium.
During the nearly six years of follow-up, about 45 percent of the patients died and 47 percent had organ rejection. About 62 percent of patients took macrolides at some point.
Organ rejection occurred in more than 61 percent of those taking macrolides. Nearly 30 percent of patients taking macrolides died, compared with more than 54 percent of those who did not take macrolides.
Macrolides are typically given only when organ rejection or inflammation occurs, Ruttens said. Since fewer patients who took macrolides died, the drugs appear to be protecting against further complications and death, he added.
The results show that both deaths and chronic rejection in lung transplant patients are associated with air pollution and exposure to traffic, Ruttens said.
If air pollution were reduced to below the level recommended by the WHO, Ruttens said, "there would be a 9.9 percent reduction in deaths among lung transplant patients who were not taking macrolides, and 6.4 percent reduction among all patients, regardless of whether or not they were taking macrolides."
The use of macrolides seems to protect patients against the devastating effects of air pollution, he concluded.
Studies presented at meetings are typically considered preliminary because they are not subject to the same scrutiny as published research.