Study on the association between rheumatoid arthritis autoantibodies and interstitial lung disease

Objective To explore the potential association between serum autoantibodies in patients with rheumatoid arthritis(RA) and RA complicated with interstitial lung disease(ILD). Methods Total 856 RA patients hospitalized in the Rheumatology and Immunology Department of the First Affiliated Hospital of Bengbu Medical College from 2015 to 2018 were retrospectively analyzed, 152 patients with secondary Sjogren's syndrome(SS) of whom were divided into another group for observation. Anti cyclic citrullinated peptide antibody(anti-CCP2) and rheumatoid factor(RF) in patients' serum were quantitatively detected. Anti-SSA/Ro52, anti-SSA/Ro60 and anti-SSB antibodies were qualitatively detected to evaluate the potential risks of these autoantibodies and ILD complicated by RA patients. Results The incidence of ILD in RA and RA secondary SS was 19.89% and 24.34%, respectively. There was no significant difference in the incidence of ILD between the groups(χ²=1.511, P=0.219). Compared with RA patients without ILD, RA patients with ILD were older, had a longer course of disease, higher anti-CCP2 antibody levels, and higher RF titers, and The differences between the two groups were statistically significant(all P<0.05). Binary logistic regression analysis of age, course of disease, and risk of multiple autoantibodies and ILD in all RA patients showed that whether RA patients had secondary SS, age, course of disease, and anti-CCP2 antibodies were significantly related to the incidence of ILD(all P<0.05). Conclusion Anti-CCP2 positive in serum of RA patients is associated with concurrent ILD. Anti-SSA/Ro60, anti-SSA/Ro52 and anti-SSB antibodies in serum of RA patients with secondary SS are not related to the onset of ILD.