Associations between periodontitis and serum anti‐malondialdehyde–acetaldehyde antibody concentrations in rheumatoid arthritis: A case‐control study

Background Malondialdehyde–acetaldehyde (MAA) adducts lead to generation of anti‐MAA autoantibodies and have been independently identified in inflamed periodontal and rheumatoid arthritis (RA) tissues. This study evaluates serum samples from RA cases and osteoarthritis (OA) controls to quantify associations between periodontal clinical measures, alveolar bone loss (ABL), and anti‐Porphyromonas gingivalis, anti‐Prevotella intermedia, and anti‐Fusobacterium nucleatum antibody concentrations with anti‐MAA antibody concentrations. Methods Participants (n = 284 RA cases, n = 330 OA controls) underwent periodontal clinical assessments and ABL measurements. Serum immunoglobulin (Ig) A, IgG, and IgM anti‐MAA and serum IgG antibacterial antibody concentrations were quantified by enzyme‐linked immunosorbent assay (ELISA). Analyses utilized simple linear regression and multivariable adjusted models. Results No significant associations of periodontal clinical measures with serum anti‐MAA were found. Moderate (p = 0.038 and p = 0.036, respectively) and high ABL (p = 0.012 and p = 0.014, respectively) in RA cases (but not in OA) were positively associated with IgG and IgM anti‐MAA. Anti‐P. gingivalis and anti‐P. intermedia antibody concentrations were positively associated with IgA (p = 0.001 for both), IgG (p = 0.007 and p = 0.034, respectively), and IgM anti‐MAA antibody concentrations (p