In laboratory findings, the positivity of ANA (81.0% vs 51.0%, p < 0.001), anti-SSA (70.5% vs 7.1%, p < 0.001) and anti-SSB (23.8% vs 2.9%, p < 0.001) were significantly higher in RA/SS patients than in RA controls. This evidence concerns the gene BTG3 and rheumatoid arthritis.