A new study found that levels of certain antibodies in the body may aid doctors in accurately predicting the likelihood of someone developing rheumatoid arthritis (RA).

Researchers found that when someone with bronchiectasis produces two specific proteins, doctors and researchers may be able to predict that person’s risk of developing RA.

Bronchiectasis a condition where the bronchial tubes of the lungs are permanently damaged through widening and thickening.

It has been known that RA can develop in people with lung involvement (e.g., interstitial lung disease and asthma), but the finding about the risk for people with bronchiectasis developing RA is new.

How RA is triggered

It seems that the inflammation involved in bronchecstatis triggers inflammation involved in RA.

The study analyzed levels of the autoantibodies related to CRT and citCRT in blood samples taken from 388 people.

Fifty of the study participants had RA, and 122 had bronchiectasis. There were also 52 people who had bronchiectasis and RA, and 87 people who had asthma and small airways diseases. Seventy-seven of the subjects were considered healthy.

Researchers said 18 percent of the subjects with bronchiectasis (those with or without rheumatoid arthritis) had the CRT antibodies in their blood.

Additionally, 35 percent of people who had either bronchiectasis or RA had citCRT antibodies. This was compared with 58 percent of the subjects who had both diseases.

The researchers also noted that 75 percent of the subjects with bronchiectasis who developed RA over the following year-and-a-half also had citCRT antibodies in their blood.

“Recently, we have demonstrated that RA patients with BR [bronchiectasis] have increased disease activity, severity, and autoantibody positivity, and that RA autoantibodies are predictors of RA developing in BR patients,” the study authors wrote. “We studied RA patients with and without BR to assist in our understanding of the prevalence of citCRT in individuals and the autoantibody response in association with other risk factors such as lung disease.”

While this finding may not be meaningful for the average person with RA, it may be useful for scientists who hope to discover more about rheumatic and autoimmune diseases, or who may try to find more targeted therapies using personalized precision medicine to treat these diseases.