Antinuclear antibody positivity Antichromatin antibody positivity 2026-08-02T11:47:06Z Eukaryotic chromatin is comprised of approximately 40% DNA, 40% histones, 20% nonhistone proteins (i.e., HMG proteins), RNA, and other macromolecules. The presence of autoantibodies (immunoglobulins) in the blood circulation that react against the chromatin. Human autoantibodies that bind to chromatin targets can be divided into those that recognize dsDNA, protein components of chromatin (i.e., histones, HMG proteins), mononucleosomes, or macromolecular components of nucleosomes as represented by low salt extracted nucleosomes (core particle).