Anti-Nucleosome Antibody as a Marker of Systemic Lupus Erythematosus Activity

Abstract
Background: Systemic Lupus Erythematosus (SLE) is a chronic multisystem autoimmune disease that is highly heter-ogeneous in its presentation. Effective SLE patient care relies on serological biomarkers. There is high interest in the iden-tification of autoantibodies other than Antinuclear Antibodies (ANA) and anti-double stranded DNA (Anti-dsDNA).
Aim: To evaluate the use of antinucleosome (Anti-NCS) antibody as a single marker to detect disease activity and renal involvement in SLE patients.
Methods and Material: This case-control study was carried out in Clinical Pathology Department at Assiut University Hospital in the period from 2014 to 2017. It included 92 patients. Sixty-two patients were diagnosed as SLE. Thirty patients had connective tissue diseases other than SLE (non-SLE). Twenty apparently healthy subjects were taken as controls. All subjects were tested for ANA, anti-dsDNA antibody and Serum anti-NCS antibody on Alegria ® (OR-GENTEC Diagnostic GmbH-Germany). Statistical analysis: Date entry and data analysis were done using SPSS Version 19, Chicago, USA (Statistical Package for Social Science).
Results: There was higher significant elevation in the level of anti-NCS antibodies than anti-dsDNA in SLE patients in comparison to those with non-SLE and control groups.In LN patients anti-NCS antibodies were highly elevated than anti-dsDNA comparing to non LN patients. Anti-NCS anti-bodies had a stronger correlation than anti-dsDNA antibodies with SLEDAI score. In 22 negative anti-dsDNA SLE patients, 13 (59.1%) were positive for anti-NCS. Anti-NCS antibodies showed higher sensitivity and specificity than anti-dsDNA in SLE and LN patients.
Conclusion: Anti-nucleosome antibodies is highly sensitive and specific in diagnosis of SLE, especially if anti-dsDNA antibodies are absent. Anti-NCS antibodies are good disease activity markers for the assessment of SLE and LN disease activity.