Rheumatoid arthritis-associated antibodies in healthy first-degree relatives of RA patients

Int J Immunogenet. 2023 Feb;50(1):19-23. doi: 10.1111/iji.12608. Epub 2022 Nov 25.

Abstract

Rheumatoid arthritis (RA) affects approximately 1.5% of the population worldwide and 0.5-3.3% of the Mexican population. The presence of rheumatoid factor (RF), anti-citrullinated protein antibodies (ACPA) and anti-carbamylated protein (anti-CarP) antibodies has been described in populations at risk of RA development, such as first-degree relatives (FDR). Anti-CarP antibodies are present in RA patients (44%), FDR of RA patients (18%) and healthy controls (4.7%). Anti-CarP antibodies have not been described in FDR of the Mexican population. The objective of this study was to determine the prevalence of Rheumatoid Factors (RF) isotypes, ACPA and anti-CarP antibodies isotypes in FDR of RA patients. An observational, cross-sectional study, in an FDR of RA cohort, was performed. We measured IgA, IgG and IgM isotypes of RF, ACPA and anti-CarP antibodies. A total of 144 FDRs from 99 RA patients were enrolled. The prevalence of anti-CarP antibodies was 2.8% for IgA, 4.2% for IgG, whereas IgM was not detected. The serologic association was for RF/ACPA 4.48%, RF/anti-CarP 2.7%, FR 64.5%, ACPA 1.3%, ACPA/anti-CarP 0.69%, anti-CarP 3.4%, and no RF/ACPA/anti-CarP was observed. We found a low prevalence of anti-CarP antibodies in our cohort of FDR of RA patients, but the prevalence of ACPA and RF were higher than other cohorts previously reported.

Keywords: HLA; antibodies; autoimmune; histocompatibility; rheumatoid arthritis.

MeSH terms

  • Arthritis, Rheumatoid* / genetics
  • Autoantibodies*
  • Cross-Sectional Studies
  • Humans
  • Immunoglobulin A
  • Immunoglobulin G
  • Rheumatoid Factor

Substances

  • Autoantibodies
  • Rheumatoid Factor
  • Immunoglobulin G
  • Immunoglobulin A