AUTOANTIBODIES TO NONHISTONE CHROMOSOMAL-PROTEINS HMG-1 AND HMG-2 IN SERA OF PATIENTS WITH JUVENILE RHEUMATOID-ARTHRITIS

IgG antibodies against the high mobility group (HMG) nonhistone chromosomal proteins HMG‐1 and/or HMG‐2 were detected in the sera of 49 (39%) of 126 antinuclear antibody (ANA)‐positive patients with juvenile rheumatoid arthritis (JRA), by immunoblotting. Clinical diagnosis classified these patients in 2 major groups, 105 with pauciarticular‐onset JRA and 21 with polyarticular‐onset JRA. Anti‐HMG‐1 and/or anti‐HMG‐2 antibodies were found in 8 (25%) of 32 pauciarticular‐onset JRA patients with uveitis and in 34 (47%) of 73 patients without uveitis, whereas anti‐HMG‐1 and/or anti‐HMG‐2 antibodies were found in 4 (24%) of 17 children with polyarticular‐onset JRA without uveitis. Among 53 sera from ANA‐negative JRA patients, 3 (6%) were positive for anti‐HMG‐1 and/or anti‐HMG‐2 antibodies, whereas no reactivity to HMG‐1 or HMG‐2 proteins was observed in 48 sera from age‐matched children with nonrheumatic diseases. Copyright © 1990 American College of Rheumatology