England BR, et al. - Investigators estimated 1823 subjects to assess the serum anti-malondialdehyde acetaldehyde (MAA) antibodies expression in lung tissues of candidates with rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) vs controls. They observed higher serum IgA and IgM anti-MAA antibody concentrations in RA-ILD as compared to RA+chronic obstructive pulmonary disease (COPD) or RA alone. They also found a significant relation of the highest quartiles of IgA and IgM anti-MAA antibody with the presence of RA-ILD, after adjusting for covariates. They noted greater MAA expression in RA-ILD lung tissues as compared to all other groups and co-localized with citrulline, CD19+ B cells, and extracellular matrix proteins (type-II collagen and vimentin) to the greatest degree in RA-ILD.