Development and detection of antinucleosome antibody by an elisa for studying the correlation in systemic lupus erythematosus patients

Abstract

To study the prevalence of antinucleosome antibody in systemic lupus erythematosus patients, the enzyme-linked immunosorbent assay (ELISA), indirect technique, was developed. In addition, the association of antinucleosome and other laboratory parameters (i.e., anti-dsDNA, C3 and C4 levels) were also evaluated. Sixty-five patient sera with systemic lupus erythematosus (SLE) were recruited. One hundred and fifteen sera were used as controls. When antinucleosome and anti-dsDNA ELISA were performed, the prevalence of antinucleosome and anti-dsDNA were 52.3% and 36.9%, respectively, indicating the frequency of antinucleosome antibody in SLE patients was higher than in anti-dsDNA antibody lupus patients. The similar results were obtained when studied in the active SLE (64.4% and 46.7% for antinucleosome and anti-dsDNA positive sera, respectively). Sixteen of 34 sera (47.1%) were shown antinucleosome without anti-dsDNA activity, suggesting that antinucleosome antibody may be a useful marker for diagnosis in anti-dsDNA negative SLE. In contrast to the active group, only 25% and 15% of the inactive SLE patients were positive for antinucleosome and anti-dsDNA antibody, respectively. Further studied in correlation analysis, we found that antinucleosome antibody activity were significantly correlated with the disease activity (SLEDAI) scores and C3 levels, however, on correlation was found between antinucleosome antibody activity and C4 levels. We conclude that antinucleosome antibody may be a useful marker in diagnosis of SLE, particularly in SLE patient whose reactivity to dsDNA is absent.