Jan 5, 2011 -- People with early rheumatoid arthritis (RA) who smoke are less likely to respond to treatment with two of the most commonly used medications -- an older disease modifying antirheumatic drug called methotrexate and biologic drugs known as TNF blockers, according to a new study in January’s Arthritis & Rheumatism.
RA is an autoimmune disease that occurs when the body’s immune system misfires against its own joints and tissues, resulting in inflammation, swelling, pain, and ultimately the loss of mobility. Treating RA early with disease-modifying antirheumatic medications is considered the best way to stop this progressive disease in its tracks.
“Our findings indicate that cigarette smokers have a diminished chance of responding well to the currently first- and second-line agents of choice in early RA treatment today,” conclude researchers who were led by Saedis Saevarsdottir, MD, PhD, a rheumatologist at the Karolinska University Hospital in Stockholm, Sweden.
Exactly how smoking affects response to RA treatment is not fully understood, but one theory suggests smokers may metabolize some RA medications differently than nonsmokers, which could compromise its effectiveness.
Of 1,430 people with early RA who were part of a Swedish registry, 873 started therapy with methotrexate and 535 started taking anti-TNF drugs within about three years of their RA diagnosis.
If they smoked (27% of them were current smokers), participants were less likely to show a good response to treatment with methotrexate or anti-TNF drugs at three months, six months, one year, and five years out when compared with their counterparts who never smoked.
Those study participants who had smoked in the past did not experience a muted response to treatment when compared to those individuals who never smoked, the study showed.
Treatment response was based on guidelines put out by the European League against Rheumatism (EULAR), the European equivalent of the American College of Rheumatology, and based on the number and degree of painful joints and other measures of disease activity.
It is still too early to tell whether quitting smoking will improve response to therapy, but it seems plausible based on the fact that past smokers responded as well to therapy as never smokers, the researchers write.
“The findings provide a strong impetus for clinicians to include measures against smoking as a fundamental part of their therapeutic armamentarium in RA care,” the researchers write.
“This is a very interesting study that provides further information on the impact of smoking on RA,” says David Pisetsky, MD, chief of rheumatology at Duke University Medical Center in Durham, N.C, in an email.
Exactly how smoking affects treatment response is not fully understood, he says. “Likely, it causes chronic inflammation which exacerbates the underlying problem in RA and limits response to therapy. Patients who smoke should definitely stop, but it may be particularly difficult given the stress of a chronic disease as well as potential effects of nicotine on pain perception.”