An analysis of clinical disease activity and nephritis-associated serum autoantibody profiles in patients with systemic lupus erythematosus: a cross-sectional study

Abstract

Objective. To establish the correlation between lupus nephritis‐associated autoantibody levels and the presence/activity of lupus nephritis and global disease activity using cross‐sectional data in patients with systemic lupus erythematosus (SLE). Methods. Disease activity was assessed using the British Isles Lupus Assessment Group (BILAG) index. Antibody levels against single‐stranded DNA (ssDNA), double‐stranded DNA (dsDNA), histones, nucleosomes and heparan sulphate (HS) were analysed by ELISA in SLE patients with (n=11) and without (n=22) nephritis and in normal controls (n=21). Antibody subclasses were also analysed. Results. Higher levels of anti‐dsDNA and anti‐HS antibodies were found in patients with lupus nephritis, the level of anti‐HS antibodies correlating with the BILAG renal score. Predominant subclasses were IgG1 and IgG3 for dsDNA antibodies, IgG2 for anti‐nucleosome antibodies, and IgG2 and IgG3 for anti‐HS antibodies. Conclusion. Correlation was demonstrated between antibodies to dsDNA, ssDNA, histones, nucleosomes and HS. There is a strong correlation between the level of anti‐HS antibodies and disease activity in patients with lupus nephritis as measured by BILAG.