Pediatric Rheumatology Online Journal → June 2003 → Epidemiology, Classification, Immunology and Immunogenetics → Abstract #3

A CLINICAL AND IMMUNOGENETIC COMPARISON OF CAUCASIAN AND NATIVE AMERICAN CHILDREN WITH JUVENILE RHEUMATOID ARTHRITIS

S. Y. Cleland,¹ B. Fishinghawk,¹ K. Sullivan,² J. N. Jarvis.¹

¹Pediatric Rheumatology Research, University of Oklahoma College of Medicine, Oklahoma City, OK; ²Pediatrics, University of Pennsylvania School of Medicine, Philadelphia, PA

Juvenile rheumatoid arthritis (JRA) has a worldwide distribution, but the phenotype varies in different ethnic groups and in different regions of the world. There is little data available on JRA in Native Americans, a group that has a high prevalence rate. Additionally, unique autoantibody profiles have been reported in Native American adults with rheumatoid arthritis. We provide clinical data on 43 Caucasian and 18 Native American children with JRA. Pauciarticular JRA was the most common JRA subtype in Caucasians, with 44% expressing this subtype. In contrast, pauciarticular-onset JRA was seen in only 17% Native American patients, and each of these patients was an adolescent, similar to what we have reported for pauciarticular-onset JRA in African Americans. The rest of the Native American children had polyarticular-onset disease, 50% of whom were IgM-RF-positive. HLA-DQA1 and TNFA 308 allele typing was performed on 37 Caucasian and 15 Native American patients with JRA. TNFA 308 allele typing showed a strong association of the A allele for Caucasian children with polyarticular JRA (OR 2.32 0.91,5.88, p = 0.0384), but this strong association was not seen among Native Americans. The HLA DQA1*0401-0601 allele was strongly associated with JRA among Caucasians (OR 15.85 1.97, 1.82 x 10¹⁰, p = 0.005), but not among American Indian patients. HLA DRB1 allele typing was performed on 22 Caucasian and 15 American Indian JRA patients. Among American Indians, HLA DRB1*0404 was significantly associated with JRA (OR 8.53 0.92, 3.89 x 10¹⁰, p = 0.029), consistent with previous studies. Native American children with JRA display a different clinical phenotype and different underlying immunogenetics compared with Caucasian children. These findings provide new insight into the pathogenesis and immunogenetics of this perplexing family of diseases.