ABSTRACT
To evaluate the prevalence of anti-nucleosome antibodies [anti-NCS Abs] in systemic lupus erythematosus [SLE], their role in diagnosis, disease activity and lupus nephritis [LN]. The study was conducted on 23 SLE female patients. They were divided into two groups according to the presence or absence of LN. Ten apparently healthy individuals served as a control group. Clinical assessment was done to all patients especially for renal affection. Disease activity was scored with SLEDAI. Anti-NCS and anti-dsDNA antibodies were measured with ELISA. Renal biopsy was performed for patients with LN. The prevalence of anti-NCS Abs was [78.3%] and anti-dsDNA Abs was [56.5%] in SLE. Seventeen patients presented with LN and 6patients without. Among these patients, the prevalence of anti-NCS Abs and anti-dsDNA Abs were [88%-64.7%] and [50%-33.3%] respectively. Anti-NCS Abs were found to be positive in 21.7% of SLE patients lacking anti-dsDNA Abs. The mean anti-NCS and anti-dsDNA Abs tiler in SLE was 250.60 +/- 207.00 and 443.3 +/- 714.3 respectively, showing a highly significant increase compared with healthy controls [12.3 +/- 4.54 and 31.0 +/- 20.11] [p<0.001]. Moreover, in LN and those without LN, the mean anti-NCS Abs showed a highly significant increase [331.41 +/- 179. 73 and 21.67 +/- 8.36] [p<0.001], while there was a significant increase in the mean of anti-ds DNA Abs [574.71 +/- 794.07 and 71.17 +/- 46.99] [p<0.05] respectively. The sensitivity and specificity of anti-NCS Abs in SLE were 82.6% and 100% and in LN were 88.2% and 100% respectively. Anti-NCS Abs showed a positive significant correlation with ESR [r=0.900], SLEDAI [r=0.761] and anti-dsDNA Abs [r=0.681] in LN, but showed a negative significant correlation with disease duration [r=-0.511] and C4 [r=-0.650] in patients without LN. In LN 7 patients hadproliferative glomerular lesion [WHO class III], 6 patients class IV and 4 patients class II on renal biopsy. They were associated with a statistically significant proteinuria, anti-ds DNA and anti-NCS especially in classes II and IV, Anti-NCS Abs could be a useful parameter for diagnosis and assessment of disease activity and LN in SLE, It seems to be a more sensitive marker of SLE than anti-ds DNA especially in patients who are anti-dsDNA antibody negative