Antihistone antibodies detected by ELISA and immunoblotting in systemic lupus erythematosus and rheumatoid arthritis

Antihistone antibodies were sought in sera from patients with systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), melanomas, leukemias and other cancers (particularly breast cancer) by micro-ELISA, using a solution of total histones as antigen. This solution contained H1 and core histones (H2A, H2B, H3 and H4). ELISA was positive in 59.8% of SLE cases, 5.2% of RA cases, 11.1% of melanomas, 13.6% of leukemias and 5.6% of other cancers. Immunoblotting using total histones enabled us to clarify the histone fraction recognized by antihistone antibodies. In SLE, these were mainly anti-H1 and anti-H2B antibodies. In RA, antibodies recognized all histone fractions. However, some sera from patients with RA stained the H4 band more intensely.