Reactivity of antinuclear antibodies with histones and other antigens in juvenile rheumatoid arthritis

Antinuclear antibodies are found in serum samples from most children with juvenile rheumatoid arthritis (JRA), but the antigenic specificities of these antibodies are not known. Using an immunoblot technique, we found that JRA patients' sera react with a variety of proteins in the nuclei of HEp-2 cells. Antibody to histone H1 was found in 42% of the JRA serum samples. An IgG antibody to a 45-kd protein was found in serum samples from some patients without uveitis, but it was not found in any sample from patients with uveitis. The immunoblot reactivity patterns do not appear to be useful in distinguishing between disease onset types or disease course types in patients with JRA.