To compare the frequencies of antibodies to high mobility group proteins 1 and 2 (HMG-1, HMG-2) in boys and girls with juvenile idiopathic arthritis (JIA).
Sera of 60 children (44 girls, 16 boys) with JIA were screened for the presence of anti-nuclear antibodies (ANA) and antichromatin antibodies by indirect immunofluorescence (IIF) on eukaryotic cells and were assayed further for the presence of antibodies to purified HMG-1 and HMG-2 by enzyme immunoassays.
A positive test for ANA was significantly associated with the presence of antibodies to both HMG-1 and HMG-2. There was a significant association between antibodies targeting the chromosomal regions of metaphase cells and antibodies to both HMG-1 and HMG-2. Females were significantly more likely than males to have ANA, and specifically more likely to have antibodies to HMG-1. There was a significant association between the presence of antibodies to HMG proteins and chromosomal reactivity detected by IIF on HEp-2 cells.
The results suggest that females with JIA are more likely to be ANA positive than males and more likely than males to have antibodies to HMG-1.