Iris protein antibodies in serum of patients with juvenile rheumatoid arthritis and uveitis.
Homogenates of bovine iris were fractionated by gel filtration chromatography, and the column-eluted proteins were probed with pooled sera obtained from patients with pauciarticular juvenile rheumatoid arthritis (JRA). The serum pool prepared from patients with pauciarticular JRA and a history of anterior uveitis, but not from those without the eye disease, contained IgG antibodies which bound a low molecular weight iris antigen (LMW-IA) as measured by a modified ELISA. LMW-IA was protease-sensitive and contained at least four proteins of approximate molecular weights of 16, 13, 9 and 6.5 kD with no uronic acid or carbohydrate. Analysis of individual patient sera for IgG anti-LMW-IA antibody demonstrated that 1/20 (5%) pediatric non-rheumatic disease controls (NRDC), 1/19 (5.3%) non-uveitic pauciarticular JRA patients and 6/21 (28.6%) uveitic pauciarticular JRA patients were positive by ELISA. Levels of anti-LMW-IA antibody did not correlate with serum IgG concentration, the presence of IgG antibody to soluble retinal S antigen (S antigen) or reactivity to the low molecular weight fraction of bovine choroid (LMW-C). Ten of 21 (47.6%) children with pauciarticular JRA and uveitis had serum antibody that reacted with LMW-IA and/or retinal S antigen as compared to 1/20 (5%) NRDC patients and 3/19 (15.8%) patients with pauciarticular JRA uncomplicated by uveitis. Analysis of patient immunoreactivity to proteins of the anterior uveal tract may provide a greater understanding of pathogenic features related to arthritis-associated eye disease.
Hunt
D W
DW
Department of Pediatrics, University of British Columbia, Vancouver, Canada.
Petty
R E
RE
Millar
F
F
D001171:Arthritis, Juvenile / Q000276:immunology*; D001323:Autoantibodies / Q000276:immunology*; D001324:Autoantigens / Q000737:chemistry / Q000276:immunology*; D002675:Child, Preschool; D005136:Eye Proteins / Q000737:chemistry / Q000276:immunology*; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007498:Iris; D008297:Male; D008970:Molecular Weight; D014605:Uveitis / Q000276:immunology*
D001323:Autoantibodies; D001324:Autoantigens; D005136:Eye Proteins; D007074:Immunoglobulin G