PRESENCE OF NUCLEOSOME-RESTRICTED ANTIBODIES IN PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS

Objective, To assess whether nucleosome-restricted antibodies, i.e., a ntibodies that react with the whole nucleosome particle but not with i ts individual components (double-stranded DNA [dsDNA] and histones), a re present in the sera of patients with systemic lupus erythematosus ( SLE), Methods, Antibodies were detected by enzyme-linked immunosorbent assay using purified nucleosomes, dsDNA, or histones. These tests wer e applied to the sera of 40 patients with SLE, Protein G-purified IgGs of representative sera were sequentially adsorbed on dsDNA- and histo ne-conjugated solid-phase supports and further assayed for their nucle osome, dsDNA, and histone reactivities, Results, Of the 40 sera tested , 16 displayed anti-dsDNA and/or antihistone antibody activity, which was always associated with significant antinucleosome reactivity, In a ddition, 3 sera showed antinucleosome activity that was not associated with concomitant anti-dsDNA or antihistone activity, The presence of true nucleosome-restricted antibodies was demonstrated, after solid-ph ase adsorption, in representative SLE sera that showed anti-dsDNA or a ntihistone antibody activity, and also in sera that did not show these activities, Conclusion. Our results provide evidence for the presence of nucleosome-restricted antibodies in patients with lupus. These nuc leosome-restricted antibodies, along with anti-dsDNA and antihistone a ntibodies, appear to belong to a broad set of antinuclear antibodies, the antinucleosome family.