Abstract:

Objective To investigate the correlations of 3 subtypes（IgG,IgM and IgA） of anti-double-stranded DNA（ds-DNA） antibodies with the disease activity of systemic lupus erythematosus（SLE） and SLE clinical phenotypes. Methods A total of 202 SLE patients were enrolled. The 3 subtypes（IgG,IgM and IgA） of anti-ds-DNA antibodies were determined by enzyme-linked immunosorbent assay（ELISA）,and the correlations of IgG,IgM and IgA anti-ds-DNA antibodies with 15 clinical phenotypes and systemic lupus erythematosus disease activity index（SLEDAI） were evaluated. Results The levels of IgG,IgM and IgA anti-ds-DNA antibodies in SLE group were higher than those in healthy control group（P<0.01）. The levels of IgM, IgA and IgG anti-ds-DNA antibodies in SLE group were from low to high in turn（P<0.01）,which were higher in SLE active group than those in SLE remission group（P<0.01）. However, the positive rates of IgG,IgM and IgA anti-ds-DNA antibodies between the 2 groups had no statistical significance（P>0.05）. Spearman correlation analysis showed that there were positive correlations of IgG, IgM and IgA anti-ds-DNA antibodies with SLEDAI in SLE group（r_s=0.446,0.249 and 0.507,P<0.01）. Clinical phenotypes,including anti-nucleosome antibody positive,anti-nuclear antibody positive,proteinuria,complement decreasing,peripheral arthritis,malar rash and alopecia,were correlated with IgG anti-ds-DNA antibody（P<0.05,P<0.01）. Anti-nucleosome antibody positive,complement decreasing,leukopenia,pleuritis and fever were correlated with IgM anti-ds-DNA antibody（P<0.05,P<0.01）. Anti-nucleosome antibody positive,anti-nuclear antibody positive,complement decreasing, peripheral arthritis and leukopenia were correlated with IgA anti-ds-DNA antibody（P<0.05,P<0.01）. Conclusions The levels of IgG and IgA anti-ds-DNA antibodies are correlated with the disease activity of SLE,while IgM has less effect in SLE. Clinical phenotypes such as anti-nucleosome antibody positive and complement decreasing show correlations with the 3 subtypes.

Key words: Anti-double-stranded DNA antibody, Systemic lupus erythematosus, Clinical phenotype, Disease activity