The study identified ‘several sputum autoantibodies of particular interest in subjects at risk for the future development of RA, including sputum ACPAs with early citrulline specificity & those with strong associations with NETs in the sputum.’
The study identified “several sputum autoantibodies of particular interest in subjects at risk for the future development of RA, including sputum ACPAs with early citrulline specificity and those with strong associations with NETs in the sputum,” conclude the authors. “These findings further support the hypothesis that the lung likely plays an important role in the development and evolution of RA-related autoimmunity,” states the article.
Dr. Demoruelle points out that among the people in the study considered at risk, some will go on to develop rheumatoid arthritis, but others will not. Future studies are planned to follow both groups to further explore the earliest features of antibody generation in the lung mucosa, she says.
“We understand that in this cross-sectional study, we can’t say that these antibody responses are all going to progress to RA,” she says. “Following them forward, even if someone’s antibody resolves over time, could be really important to understanding the bigger picture of how rheumatoid arthritis develops.”
Dr. Demoruelle notes that the ACPA test—in use for many years—was developed on the basis of citrullinated protein relevance in the joint tissue.
“Certainly, going forward, we are also interested to understand if there are unique antibody responses to citrullinated proteins in the lung that need to be identified and could be different from those that we’ve looked at, …” which have been associated with RA-related joint disease.
Catherine Kolonko is a medical writer based in Oregon.
Reference
- Demoruelle MK, Bowers E, Lahey LJ, et al. Antibody responses to citrullinated and noncitrullinated antigens in the sputum of subjects with rheumatoid arthritis and subjects at risk for development of rheumatoid arthritis. Arthritis Rheumatol. 2018 Apr;70(4):516–527.
