Nucleolar Anti-Histones (H) Antibodies (Ab) In Juvenile Dermatomyositis

Ten positive antinuclear antibody (ANA) sera from JDMS patients obtained within 4 months of disease onset were examined by indirect immunofluorescence (IF), radial immunodiffusion, hemmaglutination, and enzyme immunoassays for the specificity of the Ab. Antihistone Ab was identified by IF using HEP2-HCl washed and H reconstituted slides. No sera had Ab to Sm, RNP, SS-A, SS-B, DNA, and Sc170. Seven of ten showed the presence of IgG, IgA-H Ab, and three IgM-H Ab. All patients with anti-H Ab were reconstituted with fraction H2b and H3 and three with H2a; after reconstitution, the initial IF homogeneous-speckled pattern changed to speckled-nucleolar in 5/7 H-positive sera. In vitro complement fixation with HEP2-H reconstituted slides and JDMS sera showed that Clq but not C3 and C4 fixed this immune complex.