Clinical and serological associations of autoantibodies in patients with systemic lupus erythematosus

Abstract

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by the formation of antigen-antibody complexes which trigger an immune response. We investigate certain autoantibodies including nucleosome, double-stranded DNA (dsDNA), Smith, ribonucleoprotein, and Sjögren's syndrome-related antigens, and examine their associations with disease activity, damage accrual, and SLE-related clinical and serological manifestations in patients with SLE. We conducted a cross-sectional study with a total 293 patients (90.4% female, mean age 46.87±12.94 years) and used the Systemic Lupus Erythematosus Disease Activity Index 2000 and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) to evaluate disease activity and disease-related damage, respectively. Systemic Lupus Erythematosus Disease Activity Index scores were significantly higher in anti-nucleosome-positive (3.87±2.72 vs 2.52±2.76, p=0.004) and anti-dsDNA-positive (3.08±2.91 vs 2.04±2.48, p=0.010) patients compared with patients without these antibodies. SDI scores were also significantly higher in anti-nucleosome-positive patients (1.61±1.99 vs 0.89±1.06, p=0.004). The presence of antinucleosome (p=0.019) and anti-dsDNA antibodies (p=0.001) both correlated significantly with the incidence of nephritis; anti-La antibodies were associated with arthritis (p=0.022), and we also observed a relationship between the presence of antinucleosome antibodies and leukopenia (p=0.011). Patients with antinucleosome or anti-dsDNA antibodies had a higher disease activity and were likely to have nephritis. Antinucleosome was also associated with more damage accrual. A greater understanding of these autoantibodies could lead to the development of new approaches to more accurate assessments of SLE.

Keywords: autoantibodies; autoimmune diseases; autoimmunity; lupus nephritis.