Histone protein and peptide reactivity within patients with systemic lupus erythematosus (SLE) from the ABCoN cohort

The aim of the study was to test the hypothesis that IFN high SLE patient sera is more reactive to whole histone proteins and post-translationally modified histone peptides than IFN low patient sera. We diluted patient sera 1:250 and incubated dilutions on a nitrocellulose-platform array printed with whole protein and peptide histone antigens. In this study, serum from 30 patients subsetted into high and low interferon signature categories were profiled for IgG autoantibody reactivity to whole histone proteins, unmodified and post-translationally modified histone peptides. IFN high patient sera was found using the significance analysis of microarrays (SAM) algorithm to be significantly more reactive with whole histone and modified histone peptide antigens.