In a study of nearly 700 people whose medical records were reviewed by researchers in Sweden, current smokers were significantly more likely to develop antibodies associated with immunity to interferon beta treatment
for MS than non-smokers. These neutralizing antibodies to interferon beta may be associated with incomplete response to therapy. Anna Karin Hedström, MD, and colleagues (Karolinska Institutet, Stockholm) report their findings in Multiple Sclerosis Journal
(early online publication, August 7 2013).
MS is not contagious or directly inherited, but scientists have identified risk factors that help determine whether a person will develop MS. These factors include genes, gender, age, geography, and ethnic background. In addition, previous studies have suggested that cigarette smoking increases a person’s risk for developing MS. Some studies have also hinted that smoking contributes to disease progression (worsening), and that MS disability progressed more quickly in smokers, suggesting that quitting may delay MS progression.
People with MS taking interferon beta medications may develop immunity to the treatment demonstrated by the presence of neutralizing antibodies (Nabs) detected in their blood. These may be associated with incomplete response to therapy. A recent small study in 31 people indicated that smoking might be a factor in development of Nabs. (Journal of Neurology 2010; 257: 1703–1707)
Investigators reviewed the treatment records, antibody status, and smoking habits of 695 people with MS who had participated in Swedish epidemiologic studies. Those who were current smokers (i.e., those who had smoked in the year that antibodies were tested) showed a significantly increased risk of developing NAbs to interferon beta-1a, compared with non-smokers. There was no association between smoking before that year and the risk of developing NAbs to interferon beta-1a. In this study the investigators did not investigate whether those who developed NAbs did more poorly than those who did not, although other studies have shown such a relationship.
The authors comment that these results point to the possibility that the lungs may react to immune system activity when irritated and may alter the interferon molecule, although this idea warrants confirmation in further study. Further research also is necessary to determine whether smoking affects other MS treatments.
“The practical implications of our findings, together with previous literature, are clear,” they write. “Avoid smoking because it can trigger MS and may worsen the course of the disease.”
Watch a webcast to find out more about “Living Well with MS.”
and join a discussion in the Online Community about “Daily Life”
The National Institutes of Health provides resources to help quit smoking: visit smokefree.gov
or call 1-800-QUITNOW (1-800-784-8669).