Women who were regularly exposed to secondhand smoke as children might be at slightly increased risk of rheumatoid arthritis, a new study hints.

Rheumatoid arthritis is an autoimmune disease in which the immune system mistakenly attacks the lining of the joints. Researchers believe that a mix of genes and certain environmental factors conspire to cause the disease. And a number of studies have linked smoking to a heightened risk of RA.

The new study, published Aug. 14 in the journal Rheumatology, looked at whether childhood exposure to secondhand smoke might be a risk factor for RA, too.

The answer, researchers found, is “maybe.”

Among more than 71,000 French women followed for two decades, those exposed to secondhand smoke as kids were at somewhat higher risk of rheumatoid arthritis, versus other women. That was true of women who currently smoked, and those who’d never smoked.

But those differences were not quite significant in statistical terms. That means the association between secondhand smoke and RA risk could be a chance finding.

So while the results are “provocative,” further research is necessary, one U.S. expert said.

“It’s hard to definitively say from the data what role secondhand smoke exposure in childhood plays in RA development,” said Dr. Tamar Rubinstein, a pediatric rheumatologist at Children’s Hospital at Montefiore in New York City.

Rubinstein, who is also a member of the American College of Rheumatology, was not involved in the study.